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<!doctype html>
<title>CodeMirror: User Manual</title>
<meta charset="utf-8"/>
<link rel=stylesheet href="docs.css">
<script src="activebookmark.js"></script>
<script src="../lib/codemirror.js"></script>
<link rel="stylesheet" href="../lib/codemirror.css">
<script src="../addon/runmode/runmode.js"></script>
<script src="../addon/runmode/colorize.js"></script>
<script src="../mode/javascript/javascript.js"></script>
<script src="../mode/xml/xml.js"></script>
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<script src="../mode/htmlmixed/htmlmixed.js"></script>
<style>
dt { text-indent: -2em; padding-left: 2em; margin-top: 1em; }
dd { margin-left: 1.5em; margin-bottom: 1em; }
dt {margin-top: 1em;}
dd dl, dd dt, dd dd, dd ul { margin-top: 0; margin-bottom: 0; }
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</style>
<div id=nav>
<a href="http://codemirror.net"><h1>CodeMirror</h1><img id=logo src="logo.png"></a>
<ul>
<li><a href="../index.html">Home</a></li>
<li><a href="#overview" class=active data-default="true">Manual</a></li>
<li><a href="https://github.com/codemirror/codemirror">Code</a></li>
</ul>
<ul>
<li><a href="#usage">Basic Usage</a></li>
<li><a href="#config">Configuration</a></li>
<li><a href="#events">Events</a></li>
<li><a href="#keymaps">Key maps</a></li>
<li><a href="#commands">Commands</a></li>
<li><a href="#styling">Customized Styling</a></li>
<li><a href="#api">Programming API</a>
<ul>
<li><a href="#api_constructor">Constructor</a></li>
<li><a href="#api_content">Content manipulation</a></li>
<li><a href="#api_selection">Selection</a></li>
<li><a href="#api_configuration">Configuration</a></li>
<li><a href="#api_doc">Document management</a></li>
<li><a href="#api_history">History</a></li>
<li><a href="#api_marker">Text-marking</a></li>
<li><a href="#api_decoration">Widget, gutter, and decoration</a></li>
<li><a href="#api_sizing">Sizing, scrolling, and positioning</a></li>
<li><a href="#api_mode">Mode, state, and tokens</a></li>
<li><a href="#api_misc">Miscellaneous methods</a></li>
<li><a href="#api_static">Static properties</a></li>
</ul>
</li>
<li><a href="#addons">Addons</a></li>
<li><a href="#modeapi">Writing CodeMirror Modes</a></li>
</ul>
</div>
<article>
<section class=first id=overview>
<h2 style="position: relative">
User manual and reference guide
<span style="color: #888; font-size: 1rem; position: absolute; right: 0; bottom: 0">version 5.1.1</span>
</h2>
<p>CodeMirror is a code-editor component that can be embedded in
Web pages. The core library provides <em>only</em> the editor
component, no accompanying buttons, auto-completion, or other IDE
functionality. It does provide a rich API on top of which such
functionality can be straightforwardly implemented. See
the <a href="#addons">addons</a> included in the distribution,
and the <a href="https://github.com/codemirror/CodeMirror/wiki/CodeMirror-addons">list
of externally hosted addons</a>, for reusable
implementations of extra features.</p>
<p>CodeMirror works with language-specific modes. Modes are
JavaScript programs that help color (and optionally indent) text
written in a given language. The distribution comes with a number
of modes (see the <a href="../mode/"><code>mode/</code></a>
directory), and it isn't hard to <a href="#modeapi">write new
ones</a> for other languages.</p>
</section>
<section id=usage>
<h2>Basic Usage</h2>
<p>The easiest way to use CodeMirror is to simply load the script
and style sheet found under <code>lib/</code> in the distribution,
plus a mode script from one of the <code>mode/</code> directories.
(See <a href="compress.html">the compression helper</a> for an
easy way to combine scripts.) For example:</p>
<pre data-lang="text/html">&lt;script src="lib/codemirror.js">&lt;/script>
&lt;link rel="stylesheet" href="../lib/codemirror.css">
&lt;script src="mode/javascript/javascript.js">&lt;/script></pre>
<p>(Alternatively, use a module loader. <a href="#modloader">More
about that later.</a>)</p>
<p>Having done this, an editor instance can be created like
this:</p>
<pre data-lang="javascript">var myCodeMirror = CodeMirror(document.body);</pre>
<p>The editor will be appended to the document body, will start
empty, and will use the mode that we loaded. To have more control
over the new editor, a configuration object can be passed
to <a href="#CodeMirror"><code>CodeMirror</code></a> as a second
argument:</p>
<pre data-lang="javascript">var myCodeMirror = CodeMirror(document.body, {
value: "function myScript(){return 100;}\n",
mode: "javascript"
});</pre>
<p>This will initialize the editor with a piece of code already in
it, and explicitly tell it to use the JavaScript mode (which is
useful when multiple modes are loaded).
See <a href="#config">below</a> for a full discussion of the
configuration options that CodeMirror accepts.</p>
<p>In cases where you don't want to append the editor to an
element, and need more control over the way it is inserted, the
first argument to the <code>CodeMirror</code> function can also
be a function that, when given a DOM element, inserts it into the
document somewhere. This could be used to, for example, replace a
textarea with a real editor:</p>
<pre data-lang="javascript">var myCodeMirror = CodeMirror(function(elt) {
myTextArea.parentNode.replaceChild(elt, myTextArea);
}, {value: myTextArea.value});</pre>
<p>However, for this use case, which is a common way to use
CodeMirror, the library provides a much more powerful
shortcut:</p>
<pre data-lang="javascript">var myCodeMirror = CodeMirror.fromTextArea(myTextArea);</pre>
<p>This will, among other things, ensure that the textarea's value
is updated with the editor's contents when the form (if it is part
of a form) is submitted. See the <a href="#fromTextArea">API
reference</a> for a full description of this method.</p>
<h3 id=modloader>Module loaders</h3>
<p>The files in the CodeMirror distribution contain shims for
loading them (and their dependencies) in AMD or CommonJS
environments. If the variables <code>exports</code>
and <code>module</code> exist and have type object, CommonJS-style
require will be used. If not, but there is a
function <code>define</code> with an <code>amd</code> property
present, AMD-style (RequireJS) will be used.</p>
<p>It is possible to
use <a href="http://browserify.org/">Browserify</a> or similar
tools to statically build modules using CodeMirror. Alternatively,
use <a href="http://requirejs.org/">RequireJS</a> to dynamically
load dependencies at runtime. Both of these approaches have the
advantage that they don't use the global namespace and can, thus,
do things like load multiple versions of CodeMirror alongside each
other.</p>
<p>Here's a simple example of using RequireJS to load CodeMirror:</p>
<pre data-lang="javascript">require([
"cm/lib/codemirror", "cm/mode/htmlmixed/htmlmixed"
], function(CodeMirror) {
CodeMirror.fromTextArea(document.getElementById("code"), {
lineNumbers: true,
mode: "htmlmixed"
});
});</pre>
<p>It will automatically load the modes that the mixed HTML mode
depends on (XML, JavaScript, and CSS).</p>
</section>
<section id=config>
<h2>Configuration</h2>
<p>Both the <a href="#CodeMirror"><code>CodeMirror</code></a>
function and its <code>fromTextArea</code> method take as second
(optional) argument an object containing configuration options.
Any option not supplied like this will be taken
from <a href="#defaults"><code>CodeMirror.defaults</code></a>, an
object containing the default options. You can update this object
to change the defaults on your page.</p>
<p>Options are not checked in any way, so setting bogus option
values is bound to lead to odd errors.</p>
<p>These are the supported options:</p>
<dl>
<dt id="option_value"><code><strong>value</strong>: string|CodeMirror.Doc</code></dt>
<dd>The starting value of the editor. Can be a string, or
a <a href="#api_doc">document object</a>.</dd>
<dt id="option_mode"><code><strong>mode</strong>: string|object</code></dt>
<dd>The mode to use. When not given, this will default to the
first mode that was loaded. It may be a string, which either
simply names the mode or is
a <a href="http://en.wikipedia.org/wiki/MIME">MIME</a> type
associated with the mode. Alternatively, it may be an object
containing configuration options for the mode, with
a <code>name</code> property that names the mode (for
example <code>{name: "javascript", json: true}</code>). The demo
pages for each mode contain information about what configuration
parameters the mode supports. You can ask CodeMirror which modes
and MIME types have been defined by inspecting
the <code>CodeMirror.modes</code>
and <code>CodeMirror.mimeModes</code> objects. The first maps
mode names to their constructors, and the second maps MIME types
to mode specs.</dd>
<dt id="option_theme"><code><strong>theme</strong>: string</code></dt>
<dd>The theme to style the editor with. You must make sure the
CSS file defining the corresponding <code>.cm-s-[name]</code>
styles is loaded (see
the <a href="../theme/"><code>theme</code></a> directory in the
distribution). The default is <code>"default"</code>, for which
colors are included in <code>codemirror.css</code>. It is
possible to use multiple theming classes at once—for
example <code>"foo bar"</code> will assign both
the <code>cm-s-foo</code> and the <code>cm-s-bar</code> classes
to the editor.</dd>
<dt id="option_indentUnit"><code><strong>indentUnit</strong>: integer</code></dt>
<dd>How many spaces a block (whatever that means in the edited
language) should be indented. The default is 2.</dd>
<dt id="option_smartIndent"><code><strong>smartIndent</strong>: boolean</code></dt>
<dd>Whether to use the context-sensitive indentation that the
mode provides (or just indent the same as the line before).
Defaults to true.</dd>
<dt id="option_tabSize"><code><strong>tabSize</strong>: integer</code></dt>
<dd>The width of a tab character. Defaults to 4.</dd>
<dt id="option_indentWithTabs"><code><strong>indentWithTabs</strong>: boolean</code></dt>
<dd>Whether, when indenting, the first N*<code>tabSize</code>
spaces should be replaced by N tabs. Default is false.</dd>
<dt id="option_electricChars"><code><strong>electricChars</strong>: boolean</code></dt>
<dd>Configures whether the editor should re-indent the current
line when a character is typed that might change its proper
indentation (only works if the mode supports indentation).
Default is true.</dd>
<dt id="option_specialChars"><code><strong>specialChars</strong>: RegExp</code></dt>
<dd>A regular expression used to determine which characters
should be replaced by a
special <a href="#option_specialCharPlaceholder">placeholder</a>.
Mostly useful for non-printing special characters. The default
is <code>/[\u0000-\u0019\u00ad\u200b-\u200f\u2028\u2029\ufeff]/</code>.</dd>
<dt id="option_specialCharPlaceholder"><code><strong>specialCharPlaceholder</strong>: function(char) → Element</code></dt>
<dd>A function that, given a special character identified by
the <a href="#option_specialChars"><code>specialChars</code></a>
option, produces a DOM node that is used to represent the
character. By default, a red dot (<span style="color: red">•</span>)
is shown, with a title tooltip to indicate the character code.</dd>
<dt id="option_rtlMoveVisually"><code><strong>rtlMoveVisually</strong>: boolean</code></dt>
<dd>Determines whether horizontal cursor movement through
right-to-left (Arabic, Hebrew) text is visual (pressing the left
arrow moves the cursor left) or logical (pressing the left arrow
moves to the next lower index in the string, which is visually
right in right-to-left text). The default is <code>false</code>
on Windows, and <code>true</code> on other platforms.</dd>
<dt id="option_keyMap"><code><strong>keyMap</strong>: string</code></dt>
<dd>Configures the key map to use. The default
is <code>"default"</code>, which is the only key map defined
in <code>codemirror.js</code> itself. Extra key maps are found in
the <a href="../keymap/"><code>key map</code></a> directory. See
the <a href="#keymaps">section on key maps</a> for more
information.</dd>
<dt id="option_extraKeys"><code><strong>extraKeys</strong>: object</code></dt>
<dd>Can be used to specify extra key bindings for the editor,
alongside the ones defined
by <a href="#option_keyMap"><code>keyMap</code></a>. Should be
either null, or a valid <a href="#keymaps">key map</a> value.</dd>
<dt id="option_lineWrapping"><code><strong>lineWrapping</strong>: boolean</code></dt>
<dd>Whether CodeMirror should scroll or wrap for long lines.
Defaults to <code>false</code> (scroll).</dd>
<dt id="option_lineNumbers"><code><strong>lineNumbers</strong>: boolean</code></dt>
<dd>Whether to show line numbers to the left of the editor.</dd>
<dt id="option_firstLineNumber"><code><strong>firstLineNumber</strong>: integer</code></dt>
<dd>At which number to start counting lines. Default is 1.</dd>
<dt id="option_lineNumberFormatter"><code><strong>lineNumberFormatter</strong>: function(line: integer) → string</code></dt>
<dd>A function used to format line numbers. The function is
passed the line number, and should return a string that will be
shown in the gutter.</dd>
<dt id="option_gutters"><code><strong>gutters</strong>: array&lt;string&gt;</code></dt>
<dd>Can be used to add extra gutters (beyond or instead of the
line number gutter). Should be an array of CSS class names, each
of which defines a <code>width</code> (and optionally a
background), and which will be used to draw the background of
the gutters. <em>May</em> include
the <code>CodeMirror-linenumbers</code> class, in order to
explicitly set the position of the line number gutter (it will
default to be to the right of all other gutters). These class
names are the keys passed
to <a href="#setGutterMarker"><code>setGutterMarker</code></a>.</dd>
<dt id="option_fixedGutter"><code><strong>fixedGutter</strong>: boolean</code></dt>
<dd>Determines whether the gutter scrolls along with the content
horizontally (false) or whether it stays fixed during horizontal
scrolling (true, the default).</dd>
<dt id="option_scrollbarStyle"><code><strong>scrollbarStyle</strong>: string</code></dt>
<dd>Chooses a scrollbar implementation. The default
is <code>"native"</code>, showing native scrollbars. The core
library also provides the <code>"null"</code> style, which
completely hides the
scrollbars. <a href="#addon_simplescrollbars">Addons</a> can
implement additional scrollbar models.</dd>
<dt id="option_coverGutterNextToScrollbar"><code><strong>coverGutterNextToScrollbar</strong>: boolean</code></dt>
<dd>When <a href="#option_fixedGutter"><code>fixedGutter</code></a>
is on, and there is a horizontal scrollbar, by default the
gutter will be visible to the left of this scrollbar. If this
option is set to true, it will be covered by an element with
class <code>CodeMirror-gutter-filler</code>.</dd>
<dt id="option_inputStyle"><code><strong>inputStyle</strong>: string</code></dt>
<dd>Selects the way CodeMirror handles input and focus. The core
library defines the <code>"textarea"</code>
and <code>"contenteditable"</code> input models. On mobile
browsers, the default is <code>"contenteditable"</code>. On
desktop browsers, the default is <code>"textarea"</code>.
Support for IME and screen readers is better in
the <code>"contenteditable"</code> model. The intention is to
make it the default on modern desktop browsers in the
future.</dd>
<dt id="option_readOnly"><code><strong>readOnly</strong>: boolean|string</code></dt>
<dd>This disables editing of the editor content by the user. If
the special value <code>"nocursor"</code> is given (instead of
simply <code>true</code>), focusing of the editor is also
disallowed.</dd>
<dt id="option_showCursorWhenSelecting"><code><strong>showCursorWhenSelecting</strong>: boolean</code></dt>
<dd>Whether the cursor should be drawn when a selection is
active. Defaults to false.</dd>
<dt id="option_lineWiseCopyCut"><code><strong>lineWiseCopyCut</strong>: boolean</code></dt>
<dd>When enabled, which is the default, doing copy or cut when
there is no selection will copy or cut the whole lines that have
cursors on them.</dd>
<dt id="option_undoDepth"><code><strong>undoDepth</strong>: integer</code></dt>
<dd>The maximum number of undo levels that the editor stores.
Note that this includes selection change events. Defaults to
200.</dd>
<dt id="option_historyEventDelay"><code><strong>historyEventDelay</strong>: integer</code></dt>
<dd>The period of inactivity (in milliseconds) that will cause a
new history event to be started when typing or deleting.
Defaults to 1250.</dd>
<dt id="option_tabindex"><code><strong>tabindex</strong>: integer</code></dt>
<dd>The <a href="http://www.w3.org/TR/html401/interact/forms.html#adef-tabindex">tab
index</a> to assign to the editor. If not given, no tab index
will be assigned.</dd>
<dt id="option_autofocus"><code><strong>autofocus</strong>: boolean</code></dt>
<dd>Can be used to make CodeMirror focus itself on
initialization. Defaults to off.
When <a href="#fromTextArea"><code>fromTextArea</code></a> is
used, and no explicit value is given for this option, it will be
set to true when either the source textarea is focused, or it
has an <code>autofocus</code> attribute and no other element is
focused.</dd>
</dl>
<p>Below this a few more specialized, low-level options are
listed. These are only useful in very specific situations, you
might want to skip them the first time you read this manual.</p>
<dl>
<dt id="option_dragDrop"><code><strong>dragDrop</strong>: boolean</code></dt>
<dd>Controls whether drag-and-drop is enabled. On by default.</dd>
<dt id="option_cursorBlinkRate"><code><strong>cursorBlinkRate</strong>: number</code></dt>
<dd>Half-period in milliseconds used for cursor blinking. The default blink
rate is 530ms. By setting this to zero, blinking can be disabled. A
negative value hides the cursor entirely.</dd>
<dt id="option_cursorScrollMargin"><code><strong>cursorScrollMargin</strong>: number</code></dt>
<dd>How much extra space to always keep above and below the
cursor when approaching the top or bottom of the visible view in
a scrollable document. Default is 0.</dd>
<dt id="option_cursorHeight"><code><strong>cursorHeight</strong>: number</code></dt>
<dd>Determines the height of the cursor. Default is 1, meaning
it spans the whole height of the line. For some fonts (and by
some tastes) a smaller height (for example <code>0.85</code>),
which causes the cursor to not reach all the way to the bottom
of the line, looks better</dd>
<dt id="option_resetSelectionOnContextMenu"><code><strong>resetSelectionOnContextMenu</strong>: boolean</code></dt>
<dd>Controls whether, when the context menu is opened with a
click outside of the current selection, the cursor is moved to
the point of the click. Defaults to <code>true</code>.</dd>
<dt id="option_workTime"><code id="option_wordkDelay"><strong>workTime</strong>, <strong>workDelay</strong>: number</code></dt>
<dd>Highlighting is done by a pseudo background-thread that will
work for <code>workTime</code> milliseconds, and then use
timeout to sleep for <code>workDelay</code> milliseconds. The
defaults are 200 and 300, you can change these options to make
the highlighting more or less aggressive.</dd>
<dt id="option_pollInterval"><code><strong>pollInterval</strong>: number</code></dt>
<dd>Indicates how quickly CodeMirror should poll its input
textarea for changes (when focused). Most input is captured by
events, but some things, like IME input on some browsers, don't
generate events that allow CodeMirror to properly detect it.
Thus, it polls. Default is 100 milliseconds.</dd>
<dt id="option_flattenSpans"><code><strong>flattenSpans</strong>: boolean</code></dt>
<dd>By default, CodeMirror will combine adjacent tokens into a
single span if they have the same class. This will result in a
simpler DOM tree, and thus perform better. With some kinds of
styling (such as rounded corners), this will change the way the
document looks. You can set this option to false to disable this
behavior.</dd>
<dt id="option_addModeClass"><code><strong>addModeClass</strong>: boolean</code></dt>
<dd>When enabled (off by default), an extra CSS class will be
added to each token, indicating the
(<a href="#innerMode">inner</a>) mode that produced it, prefixed
with <code>"cm-m-"</code>. For example, tokens from the XML mode
will get the <code>cm-m-xml</code> class.</dd>
<dt id="option_maxHighlightLength"><code><strong>maxHighlightLength</strong>: number</code></dt>
<dd>When highlighting long lines, in order to stay responsive,
the editor will give up and simply style the rest of the line as
plain text when it reaches a certain position. The default is
10 000. You can set this to <code>Infinity</code> to turn off
this behavior.</dd>
<dt id="option_viewportMargin"><code><strong>viewportMargin</strong>: integer</code></dt>
<dd>Specifies the amount of lines that are rendered above and
below the part of the document that's currently scrolled into
view. This affects the amount of updates needed when scrolling,
and the amount of work that such an update does. You should
usually leave it at its default, 10. Can be set
to <code>Infinity</code> to make sure the whole document is
always rendered, and thus the browser's text search works on it.
This <em>will</em> have bad effects on performance of big
documents.</dd>
</dl>
</section>
<section id=events>
<h2>Events</h2>
<p>Various CodeMirror-related objects emit events, which allow
client code to react to various situations. Handlers for such
events can be registered with the <a href="#on"><code>on</code></a>
and <a href="#off"><code>off</code></a> methods on the objects
that the event fires on. To fire your own events,
use <code>CodeMirror.signal(target, name, args...)</code>,
where <code>target</code> is a non-DOM-node object.</p>
<p>An editor instance fires the following events.
The <code>instance</code> argument always refers to the editor
itself.</p>
<dl>
<dt id="event_change"><code><strong>"change"</strong> (instance: CodeMirror, changeObj: object)</code></dt>
<dd>Fires every time the content of the editor is changed.
The <code>changeObj</code> is a <code>{from, to, text, removed,
origin}</code> object containing information about the changes
that occurred as second argument. <code>from</code>
and <code>to</code> are the positions (in the pre-change
coordinate system) where the change started and ended (for
example, it might be <code>{ch:0, line:18}</code> if the
position is at the beginning of line #19). <code>text</code> is
an array of strings representing the text that replaced the
changed range (split by line). <code>removed</code> is the text
that used to be between <code>from</code> and <code>to</code>,
which is overwritten by this change.</dd>
<dt id="event_changes"><code><strong>"changes"</strong> (instance: CodeMirror, changes: array&lt;object&gt;)</code></dt>
<dd>Like the <a href="#event_change"><code>"change"</code></a>
event, but batched per <a href="#operation">operation</a>,
passing an array containing all the changes that happened in the
operation.</dd>
<dt id="event_beforeChange"><code><strong>"beforeChange"</strong> (instance: CodeMirror, changeObj: object)</code></dt>
<dd>This event is fired before a change is applied, and its
handler may choose to modify or cancel the change.
The <code>changeObj</code> object
has <code>from</code>, <code>to</code>, and <code>text</code>
properties, as with
the <a href="#event_change"><code>"change"</code></a> event. It
also has a <code>cancel()</code> method, which can be called to
cancel the change, and, <strong>if</strong> the change isn't
coming from an undo or redo event, an <code>update(from, to,
text)</code> method, which may be used to modify the change.
Undo or redo changes can't be modified, because they hold some
metainformation for restoring old marked ranges that is only
valid for that specific change. All three arguments
to <code>update</code> are optional, and can be left off to
leave the existing value for that field
intact. <strong>Note:</strong> you may not do anything from
a <code>"beforeChange"</code> handler that would cause changes
to the document or its visualization. Doing so will, since this
handler is called directly from the bowels of the CodeMirror
implementation, probably cause the editor to become
corrupted.</dd>
<dt id="event_cursorActivity"><code><strong>"cursorActivity"</strong> (instance: CodeMirror)</code></dt>
<dd>Will be fired when the cursor or selection moves, or any
change is made to the editor content.</dd>
<dt id="event_keyHandled"><code><strong>"keyHandled"</strong> (instance: CodeMirror, name: string, event: Event)</code></dt>
<dd>Fired after a key is handled through a
key map. <code>name</code> is the name of the handled key (for
example <code>"Ctrl-X"</code> or <code>"'q'"</code>),
and <code>event</code> is the DOM <code>keydown</code>
or <code>keypress</code> event.</dd>
<dt id="event_inputRead"><code><strong>"inputRead"</strong> (instance: CodeMirror, changeObj: object)</code></dt>
<dd>Fired whenever new input is read from the hidden textarea
(typed or pasted by the user).</dd>
<dt id="event_electricInput"><code><strong>"electrictInput"</strong> (instance: CodeMirror, line: integer)</code></dt>
<dd>Fired if text input matched the
mode's <a href="#option_electricChars">electric</a> patterns,
and this caused the line's indentation to change.</dd>
<dt id="event_beforeSelectionChange"><code><strong>"beforeSelectionChange"</strong> (instance: CodeMirror, obj: {ranges, update})</code></dt>
<dd>This event is fired before the selection is moved. Its
handler may inspect the set of selection ranges, present as an
array of <code>{anchor, head}</code> objects in
the <code>ranges</code> property of the <code>obj</code>
argument, and optionally change them by calling
the <code>update</code> method on this object, passing an array
of ranges in the same format. Handlers for this event have the
same restriction
as <a href="#event_beforeChange"><code>"beforeChange"</code></a>
handlers — they should not do anything to directly update the
state of the editor.</dd>
<dt id="event_viewportChange"><code><strong>"viewportChange"</strong> (instance: CodeMirror, from: number, to: number)</code></dt>
<dd>Fires whenever the <a href="#getViewport">view port</a> of
the editor changes (due to scrolling, editing, or any other
factor). The <code>from</code> and <code>to</code> arguments
give the new start and end of the viewport.</dd>
<dt id="event_swapDoc"><code><strong>"swapDoc"</strong> (instance: CodeMirror, oldDoc: Doc)</code></dt>
<dd>This is signalled when the editor's document is replaced
using the <a href="#swapDoc"><code>swapDoc</code></a>
method.</dd>
<dt id="event_gutterClick"><code><strong>"gutterClick"</strong> (instance: CodeMirror, line: integer, gutter: string, clickEvent: Event)</code></dt>
<dd>Fires when the editor gutter (the line-number area) is
clicked. Will pass the editor instance as first argument, the
(zero-based) number of the line that was clicked as second
argument, the CSS class of the gutter that was clicked as third
argument, and the raw <code>mousedown</code> event object as
fourth argument.</dd>
<dt id="event_gutterContextMenu"><code><strong>"gutterContextMenu"</strong> (instance: CodeMirror, line: integer, gutter: string, contextMenu: Event: Event)</code></dt>
<dd>Fires when the editor gutter (the line-number area)
receives a <code>contextmenu</code> event. Will pass the editor
instance as first argument, the (zero-based) number of the line
that was clicked as second argument, the CSS class of the
gutter that was clicked as third argument, and the raw
<code>contextmenu</code> mouse event object as fourth argument.
You can <code>preventDefault</code> the event, to signal that
CodeMirror should do no further handling.</dd>
<dt id="event_focus"><code><strong>"focus"</strong> (instance: CodeMirror)</code></dt>
<dd>Fires whenever the editor is focused.</dd>
<dt id="event_blur"><code><strong>"blur"</strong> (instance: CodeMirror)</code></dt>
<dd>Fires whenever the editor is unfocused.</dd>
<dt id="event_scroll"><code><strong>"scroll"</strong> (instance: CodeMirror)</code></dt>
<dd>Fires when the editor is scrolled.</dd>
<dt id="event_scrollCursorIntoView"><code><strong>"scrollCursorIntoView"</strong> (instance: CodeMirror, event: Event)</code></dt>
<dd>Fires when the editor tries to scroll its cursor into view.
Can be hooked into to take care of additional scrollable
containers around the editor. When the event object has
its <code>preventDefault</code> method called, CodeMirror will
not itself try to scroll the window.</dd>
<dt id="event_update"><code><strong>"update"</strong> (instance: CodeMirror)</code></dt>
<dd>Will be fired whenever CodeMirror updates its DOM display.</dd>
<dt id="event_renderLine"><code><strong>"renderLine"</strong> (instance: CodeMirror, line: LineHandle, element: Element)</code></dt>
<dd>Fired whenever a line is (re-)rendered to the DOM. Fired
right after the DOM element is built, <em>before</em> it is
added to the document. The handler may mess with the style of
the resulting element, or add event handlers, but
should <em>not</em> try to change the state of the editor.</dd>
<dt id="event_dom"><code><strong>"mousedown"</strong>,
<strong>"dblclick"</strong>, <strong>"contextmenu"</strong>, <strong>"keydown"</strong>, <strong>"keypress"</strong>,
<strong>"keyup"</strong>, <strong>"dragstart"</strong>, <strong>"dragenter"</strong>,
<strong>"dragover"</strong>, <strong>"drop"</strong>
(instance: CodeMirror, event: Event)</code></dt>
<dd>Fired when CodeMirror is handling a DOM event of this type.
You can <code>preventDefault</code> the event, or give it a
truthy <code>codemirrorIgnore</code> property, to signal that
CodeMirror should do no further handling.</dd>
</dl>
<p>Document objects (instances
of <a href="#Doc"><code>CodeMirror.Doc</code></a>) emit the
following events:</p>
<dl>
<dt id="event_doc_change"><code><strong>"change"</strong> (doc: CodeMirror.Doc, changeObj: object)</code></dt>
<dd>Fired whenever a change occurs to the
document. <code>changeObj</code> has a similar type as the
object passed to the
editor's <a href="#event_change"><code>"change"</code></a>
event.</dd>
<dt id="event_doc_beforeChange"><code><strong>"beforeChange"</strong> (doc: CodeMirror.Doc, change: object)</code></dt>
<dd>See the <a href="#event_beforeChange">description of the
same event</a> on editor instances.</dd>
<dt id="event_doc_cursorActivity"><code><strong>"cursorActivity"</strong> (doc: CodeMirror.Doc)</code></dt>
<dd>Fired whenever the cursor or selection in this document
changes.</dd>
<dt id="event_doc_beforeSelectionChange"><code><strong>"beforeSelectionChange"</strong> (doc: CodeMirror.Doc, selection: {head, anchor})</code></dt>
<dd>Equivalent to
the <a href="#event_beforeSelectionChange">event by the same
name</a> as fired on editor instances.</dd>
</dl>
<p>Line handles (as returned by, for
example, <a href="#getLineHandle"><code>getLineHandle</code></a>)
support these events:</p>
<dl>
<dt id="event_delete"><code><strong>"delete"</strong> ()</code></dt>
<dd>Will be fired when the line object is deleted. A line object
is associated with the <em>start</em> of the line. Mostly useful
when you need to find out when your <a href="#setGutterMarker">gutter
markers</a> on a given line are removed.</dd>
<dt id="event_line_change"><code><strong>"change"</strong> (line: LineHandle, changeObj: object)</code></dt>
<dd>Fires when the line's text content is changed in any way
(but the line is not deleted outright). The <code>change</code>
object is similar to the one passed
to <a href="#event_change">change event</a> on the editor
object.</dd>
</dl>
<p>Marked range handles (<code>CodeMirror.TextMarker</code>), as returned
by <a href="#markText"><code>markText</code></a>
and <a href="#setBookmark"><code>setBookmark</code></a>, emit the
following events:</p>
<dl>
<dt id="event_beforeCursorEnter"><code><strong>"beforeCursorEnter"</strong> ()</code></dt>
<dd>Fired when the cursor enters the marked range. From this
event handler, the editor state may be inspected
but <em>not</em> modified, with the exception that the range on
which the event fires may be cleared.</dd>
<dt id="event_clear"><code><strong>"clear"</strong> (from: {line, ch}, to: {line, ch})</code></dt>
<dd>Fired when the range is cleared, either through cursor
movement in combination
with <a href="#mark_clearOnEnter"><code>clearOnEnter</code></a>
or through a call to its <code>clear()</code> method. Will only
be fired once per handle. Note that deleting the range through
text editing does not fire this event, because an undo action
might bring the range back into existence. <code>from</code>
and <code>to</code> give the part of the document that the range
spanned when it was cleared.</dd>
<dt id="event_hide"><code><strong>"hide"</strong> ()</code></dt>
<dd>Fired when the last part of the marker is removed from the
document by editing operations.</dd>
<dt id="event_unhide"><code><strong>"unhide"</strong> ()</code></dt>
<dd>Fired when, after the marker was removed by editing, a undo
operation brought the marker back.</dd>
</dl>
<p>Line widgets (<code>CodeMirror.LineWidget</code>), returned
by <a href="#addLineWidget"><code>addLineWidget</code></a>, fire
these events:</p>
<dl>
<dt id="event_redraw"><code><strong>"redraw"</strong> ()</code></dt>
<dd>Fired whenever the editor re-adds the widget to the DOM.
This will happen once right after the widget is added (if it is
scrolled into view), and then again whenever it is scrolled out
of view and back in again, or when changes to the editor options
or the line the widget is on require the widget to be
redrawn.</dd>
</dl>
</section>
<section id=keymaps>
<h2>Key Maps</h2>
<p>Key maps are ways to associate keys with functionality. A key map
is an object mapping strings that identify the keys to functions
that implement their functionality.</p>
<p>The CodeMirror distributions comes
with <a href="../demo/emacs.html">Emacs</a>, <a href="../demo/vim.html">Vim</a>,
and <a href="../demo/sublime.html">Sublime Text</a>-style keymaps.</p>
<p>Keys are identified either by name or by character.
The <code>CodeMirror.keyNames</code> object defines names for
common keys and associates them with their key codes. Examples of
names defined here are <code>Enter</code>, <code>F5</code>,
and <code>Q</code>. These can be prefixed
with <code>Shift-</code>, <code>Cmd-</code>, <code>Ctrl-</code>,
and <code>Alt-</code> to specify a modifier. So for
example, <code>Shift-Ctrl-Space</code> would be a valid key
identifier.</p>
<p>Common example: map the Tab key to insert spaces instead of a tab
character.</p>
<pre data-lang="javascript">
editor.setOption("extraKeys", {
Tab: function(cm) {
var spaces = Array(cm.getOption("indentUnit") + 1).join(" ");
cm.replaceSelection(spaces);
}
});</pre>
<p>Alternatively, a character can be specified directly by
surrounding it in single quotes, for example <code>'$'</code>
or <code>'q'</code>. Due to limitations in the way browsers fire
key events, these may not be prefixed with modifiers.</p>
<p id="normalizeKeyMap">Multi-stroke key bindings can be specified
by separating the key names by spaces in the property name, for
example <code>Ctrl-X Ctrl-V</code>. When a map contains
multi-stoke bindings or keys with modifiers that are not specified
in the default order (<code>Shift-Cmd-Ctrl-Alt</code>), you must
call <code>CodeMirror.normalizeKeyMap</code> on it before it can
be used. This function takes a keymap and modifies it to normalize
modifier order and properly recognize multi-stroke bindings. It
will return the keymap itself.</p>
<p>The <code>CodeMirror.keyMap</code> object associates key maps
with names. User code and key map definitions can assign extra
properties to this object. Anywhere where a key map is expected, a
string can be given, which will be looked up in this object. It
also contains the <code>"default"</code> key map holding the
default bindings.</p>
<p>The values of properties in key maps can be either functions of
a single argument (the CodeMirror instance), strings, or
<code>false</code>. Strings refer
to <a href="#commands">commands</a>, which are described below. If
the property is set to <code>false</code>, CodeMirror leaves
handling of the key up to the browser. A key handler function may
return <code>CodeMirror.Pass</code> to indicate that it has
decided not to handle the key, and other handlers (or the default
behavior) should be given a turn.</p>
<p>Keys mapped to command names that start with the
characters <code>"go"</code> or to functions that have a
truthy <code>motion</code> property (which should be used for
cursor-movement actions) will be fired even when an
extra <code>Shift</code> modifier is present (i.e. <code>"Up":
"goLineUp"</code> matches both up and shift-up). This is used to
easily implement shift-selection.</p>
<p>Key maps can defer to each other by defining
a <code>fallthrough</code> property. This indicates that when a
key is not found in the map itself, one or more other maps should
be searched. It can hold either a single key map or an array of
key maps.</p>
<p>When a key map needs to set something up when it becomes
active, or tear something down when deactivated, it can
contain <code>attach</code> and/or <code>detach</code> properties,
which should hold functions that take the editor instance and the
next or previous keymap. Note that this only works for the
<a href="#option_keyMap">top-level keymap</a>, not for fallthrough
maps or maps added
with <a href="#option_extraKeys"><code>extraKeys</code></a>
or <a href="#addKeyMap"><code>addKeyMap</code></a>.</p>
</section>
<section id=commands>
<h2>Commands</h2>
<p>Commands are parameter-less actions that can be performed on an
editor. Their main use is for key bindings. Commands are defined by
adding properties to the <code>CodeMirror.commands</code> object.
A number of common commands are defined by the library itself,
most of them used by the default key bindings. The value of a
command property must be a function of one argument (an editor
instance).</p>
<p>Some of the commands below are referenced in the default
key map, but not defined by the core library. These are intended to
be defined by user code or addons.</p>
<p>Commands can also be run with
the <a href="#execCommand"><code>execCommand</code></a>
method.</p>
<dl>
<dt class=command id=command_selectAll><code><strong>selectAll</strong></code><span class=keybinding>Ctrl-A (PC), Cmd-A (Mac)</span></dt>
<dd>Select the whole content of the editor.</dd>
<dt class=command id=command_singleSelection><code><strong>singleSelection</strong></code><span class=keybinding>Esc</span></dt>
<dd>When multiple selections are present, this deselects all but
the primary selection.</dd>
<dt class=command id=command_killLine><code><strong>killLine</strong></code><span class=keybinding>Ctrl-K (Mac)</span></dt>
<dd>Emacs-style line killing. Deletes the part of the line after
the cursor. If that consists only of whitespace, the newline at
the end of the line is also deleted.</dd>
<dt class=command id=command_deleteLine><code><strong>deleteLine</strong></code><span class=keybinding>Ctrl-D (PC), Cmd-D (Mac)</span></dt>
<dd>Deletes the whole line under the cursor, including newline at the end.</dd>
<dt class=command id=command_delLineLeft><code><strong>delLineLeft</strong></code></dt>
<dd>Delete the part of the line before the cursor.</dd>
<dt class=command id=command_delWrappedLineLeft><code><strong>delWrappedLineLeft</strong></code><span class=keybinding>Cmd-Backspace (Mac)</span></dt>
<dd>Delete the part of the line from the left side of the visual line the cursor is on to the cursor.</dd>
<dt class=command id=command_delWrappedLineRight><code><strong>delWrappedLineRight</strong></code><span class=keybinding>Cmd-Delete (Mac)</span></dt>
<dd>Delete the part of the line from the cursor to the right side of the visual line the cursor is on.</dd>
<dt class=command id=command_undo><code><strong>undo</strong></code><span class=keybinding>Ctrl-Z (PC), Cmd-Z (Mac)</span></dt>
<dd>Undo the last change.</dd>
<dt class=command id=command_redo><code><strong>redo</strong></code><span class=keybinding>Ctrl-Y (PC), Shift-Cmd-Z (Mac), Cmd-Y (Mac)</span></dt>
<dd>Redo the last undone change.</dd>
<dt class=command id=command_undoSelection><code><strong>undoSelection</strong></code><span class=keybinding>Ctrl-U (PC), Cmd-U (Mac)</span></dt>
<dd>Undo the last change to the selection, or if there are no
selection-only changes at the top of the history, undo the last
change.</dd>
<dt class=command id=command_redoSelection><code><strong>redoSelection</strong></code><span class=keybinding>Alt-U (PC), Shift-Cmd-U (Mac)</span></dt>
<dd>Redo the last change to the selection, or the last text change if
no selection changes remain.</dd>
<dt class=command id=command_goDocStart><code><strong>goDocStart</strong></code><span class=keybinding>Ctrl-Home (PC), Cmd-Up (Mac), Cmd-Home (Mac)</span></dt>
<dd>Move the cursor to the start of the document.</dd>
<dt class=command id=command_goDocEnd><code><strong>goDocEnd</strong></code><span class=keybinding>Ctrl-End (PC), Cmd-End (Mac), Cmd-Down (Mac)</span></dt>
<dd>Move the cursor to the end of the document.</dd>
<dt class=command id=command_goLineStart><code><strong>goLineStart</strong></code><span class=keybinding>Alt-Left (PC), Ctrl-A (Mac)</span></dt>
<dd>Move the cursor to the start of the line.</dd>
<dt class=command id=command_goLineStartSmart><code><strong>goLineStartSmart</strong></code><span class=keybinding>Home</span></dt>
<dd>Move to the start of the text on the line, or if we are
already there, to the actual start of the line (including
whitespace).</dd>
<dt class=command id=command_goLineEnd><code><strong>goLineEnd</strong></code><span class=keybinding>Alt-Right (PC), Ctrl-E (Mac)</span></dt>
<dd>Move the cursor to the end of the line.</dd>
<dt class=command id=command_goLineRight><code><strong>goLineRight</strong></code><span class=keybinding>Cmd-Right (Mac)</span></dt>
<dd>Move the cursor to the right side of the visual line it is on.</dd>
<dt class=command id=command_goLineLeft><code><strong>goLineLeft</strong></code><span class=keybinding>Cmd-Left (Mac)</span></dt>
<dd>Move the cursor to the left side of the visual line it is on. If
this line is wrapped, that may not be the start of the line.</dd>
<dt class=command id=command_goLineLeftSmart><code><strong>goLineLeftSmart</strong></code></dt>
<dd>Move the cursor to the left side of the visual line it is
on. If that takes it to the start of the line, behave
like <a href="#command_goLineStartSmart"><code>goLineStartSmart</code></a>.</dd>
<dt class=command id=command_goLineUp><code><strong>goLineUp</strong></code><span class=keybinding>Up, Ctrl-P (Mac)</span></dt>
<dd>Move the cursor up one line.</dd>
<dt class=command id=command_goLineDown><code><strong>goLineDown</strong></code><span class=keybinding>Down, Ctrl-N (Mac)</span></dt>
<dd>Move down one line.</dd>
<dt class=command id=command_goPageUp><code><strong>goPageUp</strong></code><span class=keybinding>PageUp, Shift-Ctrl-V (Mac)</span></dt>
<dd>Move the cursor up one screen, and scroll up by the same distance.</dd>
<dt class=command id=command_goPageDown><code><strong>goPageDown</strong></code><span class=keybinding>PageDown, Ctrl-V (Mac)</span></dt>
<dd>Move the cursor down one screen, and scroll down by the same distance.</dd>
<dt class=command id=command_goCharLeft><code><strong>goCharLeft</strong></code><span class=keybinding>Left, Ctrl-B (Mac)</span></dt>
<dd>Move the cursor one character left, going to the previous line
when hitting the start of line.</dd>
<dt class=command id=command_goCharRight><code><strong>goCharRight</strong></code><span class=keybinding>Right, Ctrl-F (Mac)</span></dt>
<dd>Move the cursor one character right, going to the next line
when hitting the end of line.</dd>
<dt class=command id=command_goColumnLeft><code><strong>goColumnLeft</strong></code></dt>
<dd>Move the cursor one character left, but don't cross line boundaries.</dd>
<dt class=command id=command_goColumnRight><code><strong>goColumnRight</strong></code></dt>
<dd>Move the cursor one character right, don't cross line boundaries.</dd>
<dt class=command id=command_goWordLeft><code><strong>goWordLeft</strong></code><span class=keybinding>Alt-B (Mac)</span></dt>
<dd>Move the cursor to the start of the previous word.</dd>
<dt class=command id=command_goWordRight><code><strong>goWordRight</strong></code><span class=keybinding>Alt-F (Mac)</span></dt>
<dd>Move the cursor to the end of the next word.</dd>
<dt class=command id=command_goGroupLeft><code><strong>goGroupLeft</strong></code><span class=keybinding>Ctrl-Left (PC), Alt-Left (Mac)</span></dt>
<dd>Move to the left of the group before the cursor. A group is
a stretch of word characters, a stretch of punctuation
characters, a newline, or a stretch of <em>more than one</em>
whitespace character.</dd>
<dt class=command id=command_goGroupRight><code><strong>goGroupRight</strong></code><span class=keybinding>Ctrl-Right (PC), Alt-Right (Mac)</span></dt>
<dd>Move to the right of the group after the cursor
(see <a href="#command_goGroupLeft">above</a>).</dd>
<dt class=command id=command_delCharBefore><code><strong>delCharBefore</strong></code><span class=keybinding>Shift-Backspace, Ctrl-H (Mac)</span></dt>
<dd>Delete the character before the cursor.</dd>
<dt class=command id=command_delCharAfter><code><strong>delCharAfter</strong></code><span class=keybinding>Delete, Ctrl-D (Mac)</span></dt>
<dd>Delete the character after the cursor.</dd>
<dt class=command id=command_delWordBefore><code><strong>delWordBefore</strong></code><span class=keybinding>Alt-Backspace (Mac)</span></dt>
<dd>Delete up to the start of the word before the cursor.</dd>
<dt class=command id=command_delWordAfter><code><strong>delWordAfter</strong></code><span class=keybinding>Alt-D (Mac)</span></dt>
<dd>Delete up to the end of the word after the cursor.</dd>
<dt class=command id=command_delGroupBefore><code><strong>delGroupBefore</strong></code><span class=keybinding>Ctrl-Backspace (PC), Alt-Backspace (Mac)</span></dt>
<dd>Delete to the left of the <a href="#command_goGroupLeft">group</a> before the cursor.</dd>
<dt class=command id=command_delGroupAfter><code><strong>delGroupAfter</strong></code><span class=keybinding>Ctrl-Delete (PC), Ctrl-Alt-Backspace (Mac), Alt-Delete (Mac)</span></dt>
<dd>Delete to the start of the <a href="#command_goGroupLeft">group</a> after the cursor.</dd>
<dt class=command id=command_indentAuto><code><strong>indentAuto</strong></code><span class=keybinding>Shift-Tab</span></dt>
<dd>Auto-indent the current line or selection.</dd>
<dt class=command id=command_indentMore><code><strong>indentMore</strong></code><span class=keybinding>Ctrl-] (PC), Cmd-] (Mac)</span></dt>
<dd>Indent the current line or selection by one <a href="#option_indentUnit">indent unit</a>.</dd>
<dt class=command id=command_indentLess><code><strong>indentLess</strong></code><span class=keybinding>Ctrl-[ (PC), Cmd-[ (Mac)</span></dt>
<dd>Dedent the current line or selection by one <a href="#option_indentUnit">indent unit</a>.</dd>
<dt class=command id=command_insertTab><code><strong>insertTab</strong></code></dt>
<dd>Insert a tab character at the cursor.</dd>
<dt class=command id=command_insertSoftTab><code><strong>insertSoftTab</strong></code></dt>
<dd>Insert the amount of spaces that match the width a tab at
the cursor position would have.</dd>
<dt class=command id=command_defaultTab><code><strong>defaultTab</strong></code><span class=keybinding>Tab</span></dt>
<dd>If something is selected, indent it by
one <a href="#option_indentUnit">indent unit</a>. If nothing is
selected, insert a tab character.</dd>
<dt class=command id=command_transposeChars><code><strong>transposeChars</strong></code><span class=keybinding>Ctrl-T (Mac)</span></dt>
<dd>Swap the characters before and after the cursor.</dd>
<dt class=command id=command_newlineAndIndent><code><strong>newlineAndIndent</strong></code><span class=keybinding>Enter</span></dt>
<dd>Insert a newline and auto-indent the new line.</dd>
<dt class=command id=command_toggleOverwrite><code><strong>toggleOverwrite</strong></code><span class=keybinding>Insert</span></dt>
<dd>Flip the <a href="#toggleOverwrite">overwrite</a> flag.</dd>
<dt class=command id=command_save><code><strong>save</strong></code><span class=keybinding>Ctrl-S (PC), Cmd-S (Mac)</span></dt>
<dd>Not defined by the core library, only referred to in
key maps. Intended to provide an easy way for user code to define
a save command.</dd>
<dt class=command id=command_find><code><strong>find</strong></code><span class=keybinding>Ctrl-F (PC), Cmd-F (Mac)</span></dt>
<dt class=command id=command_findNext><code><strong>findNext</strong></code><span class=keybinding>Ctrl-G (PC), Cmd-G (Mac)</span></dt>
<dt class=command id=command_findPrev><code><strong>findPrev</strong></code><span class=keybinding>Shift-Ctrl-G (PC), Shift-Cmd-G (Mac)</span></dt>
<dt class=command id=command_replace><code><strong>replace</strong></code><span class=keybinding>Shift-Ctrl-F (PC), Cmd-Alt-F (Mac)</span></dt>
<dt class=command id=command_replaceAll><code><strong>replaceAll</strong></code><span class=keybinding>Shift-Ctrl-R (PC), Shift-Cmd-Alt-F (Mac)</span></dt>
<dd>Not defined by the core library, but defined in
the <a href="#addon_search">search addon</a> (or custom client
addons).</dd>
</dl>
</section>
<section id=styling>
<h2>Customized Styling</h2>
<p>Up to a certain extent, CodeMirror's look can be changed by
modifying style sheet files. The style sheets supplied by modes
simply provide the colors for that mode, and can be adapted in a
very straightforward way. To style the editor itself, it is
possible to alter or override the styles defined
in <a href="../lib/codemirror.css"><code>codemirror.css</code></a>.</p>
<p>Some care must be taken there, since a lot of the rules in this
file are necessary to have CodeMirror function properly. Adjusting
colors should be safe, of course, and with some care a lot of
other things can be changed as well. The CSS classes defined in
this file serve the following roles:</p>
<dl>
<dt id="class_CodeMirror"><code><strong>CodeMirror</strong></code></dt>
<dd>The outer element of the editor. This should be used for the
editor width, height, borders and positioning. Can also be used
to set styles that should hold for everything inside the editor
(such as font and font size), or to set a background. Setting
this class' <code>height</code> style to <code>auto</code> will
make the editor <a href="../demo/resize.html">resize to fit its
content</a> (it is recommended to also set
the <a href="#option_viewportMargin"><code>viewportMargin</code>
option</a> to <code>Infinity</code> when doing this.</dd>
<dt id="class_CodeMirror_focused"><code><strong>CodeMirror-focused</strong></code></dt>
<dd>Whenever the editor is focused, the top element gets this
class. This is used to hide the cursor and give the selection a
different color when the editor is not focused.</dd>
<dt id="class_CodeMirror_gutters"><code><strong>CodeMirror-gutters</strong></code></dt>
<dd>This is the backdrop for all gutters. Use it to set the
default gutter background color, and optionally add a border on
the right of the gutters.</dd>
<dt id="class_CodeMirror_linenumbers"><code><strong>CodeMirror-linenumbers</strong></code></dt>
<dd>Use this for giving a background or width to the line number
gutter.</dd>
<dt id="class_CodeMirror_linenumber"><code><strong>CodeMirror-linenumber</strong></code></dt>
<dd>Used to style the actual individual line numbers. These
won't be children of the <code>CodeMirror-linenumbers</code>
(plural) element, but rather will be absolutely positioned to
overlay it. Use this to set alignment and text properties for
the line numbers.</dd>
<dt id="class_CodeMirror_lines"><code><strong>CodeMirror-lines</strong></code></dt>
<dd>The visible lines. This is where you specify vertical
padding for the editor content.</dd>
<dt id="class_CodeMirror_cursor"><code><strong>CodeMirror-cursor</strong></code></dt>
<dd>The cursor is a block element that is absolutely positioned.
You can make it look whichever way you want.</dd>
<dt id="class_CodeMirror_selected"><code><strong>CodeMirror-selected</strong></code></dt>
<dd>The selection is represented by <code>span</code> elements
with this class.</dd>
<dt id="class_CodeMirror_matchingbracket"><code><strong>CodeMirror-matchingbracket</strong></code>,
<code><strong>CodeMirror-nonmatchingbracket</strong></code></dt>
<dd>These are used to style matched (or unmatched) brackets.</dd>
</dl>
<p>If your page's style sheets do funky things to
all <code>div</code> or <code>pre</code> elements (you probably
shouldn't do that), you'll have to define rules to cancel these
effects out again for elements under the <code>CodeMirror</code>
class.</p>
<p>Themes are also simply CSS files, which define colors for
various syntactic elements. See the files in
the <a href="../theme/"><code>theme</code></a> directory.</p>
</section>
<section id=api>
<h2>Programming API</h2>
<p>A lot of CodeMirror features are only available through its
API. Thus, you need to write code (or
use <a href="#addons">addons</a>) if you want to expose them to
your users.</p>
<p>Whenever points in the document are represented, the API uses
objects with <code>line</code> and <code>ch</code> properties.
Both are zero-based. CodeMirror makes sure to 'clip' any positions
passed by client code so that they fit inside the document, so you
shouldn't worry too much about sanitizing your coordinates. If you
give <code>ch</code> a value of <code>null</code>, or don't
specify it, it will be replaced with the length of the specified
line.</p>
<p>Methods prefixed with <code>doc.</code> can, unless otherwise
specified, be called both on <code>CodeMirror</code> (editor)
instances and <code>CodeMirror.Doc</code> instances. Methods
prefixed with <code>cm.</code> are <em>only</em> available
on <code>CodeMirror</code> instances.</p>
<h3 id="api_constructor">Constructor</h3>
<p id="CodeMirror">Constructing an editor instance is done with
the <code><strong>CodeMirror</strong>(place: Element|fn(Element),
?option: object)</code> constructor. If the <code>place</code>
argument is a DOM element, the editor will be appended to it. If
it is a function, it will be called, and is expected to place the
editor into the document. <code>options</code> may be an element
mapping <a href="#config">option names</a> to values. The options
that it doesn't explicitly specify (or all options, if it is not
passed) will be taken
from <a href="#defaults"><code>CodeMirror.defaults</code></a>.</p>
<p>Note that the options object passed to the constructor will be
mutated when the instance's options
are <a href="#setOption">changed</a>, so you shouldn't share such
objects between instances.</p>
<p>See <a href="#fromTextArea"><code>CodeMirror.fromTextArea</code></a>
for another way to construct an editor instance.</p>
<h3 id="api_content">Content manipulation methods</h3>
<dl>
<dt id="getValue"><code><strong>doc.getValue</strong>(?separator: string) → string</code></dt>
<dd>Get the current editor content. You can pass it an optional
argument to specify the string to be used to separate lines
(defaults to <code>"\n"</code>).</dd>
<dt id="setValue"><code><strong>doc.setValue</strong>(content: string)</code></dt>
<dd>Set the editor content.</dd>
<dt id="getRange"><code><strong>doc.getRange</strong>(from: {line, ch}, to: {line, ch}, ?separator: string) → string</code></dt>
<dd>Get the text between the given points in the editor, which
should be <code>{line, ch}</code> objects. An optional third
argument can be given to indicate the line separator string to
use (defaults to <code>"\n"</code>).</dd>
<dt id="replaceRange"><code><strong>doc.replaceRange</strong>(replacement: string, from: {line, ch}, to: {line, ch}, ?origin: string)</code></dt>
<dd>Replace the part of the document between <code>from</code>
and <code>to</code> with the given string. <code>from</code>
and <code>to</code> must be <code>{line, ch}</code>
objects. <code>to</code> can be left off to simply insert the
string at position <code>from</code>. When <code>origin</code>
is given, it will be passed on
to <a href="#event_change"><code>"change"</code> events</a>, and
its first letter will be used to determine whether this change
can be merged with previous history events, in the way described
for <a href="#selection_origin">selection origins</a>.</dd>
<dt id="getLine"><code><strong>doc.getLine</strong>(n: integer) → string</code></dt>
<dd>Get the content of line <code>n</code>.</dd>
<dt id="lineCount"><code><strong>doc.lineCount</strong>() → integer</code></dt>
<dd>Get the number of lines in the editor.</dd>
<dt id="firstLine"><code><strong>doc.firstLine</strong>() → integer</code></dt>
<dd>Get the first line of the editor. This will
usually be zero but for <a href="#linkedDoc_from">linked sub-views</a>,
or <a href="#api_doc">documents</a> instantiated with a non-zero
first line, it might return other values.</dd>
<dt id="lastLine"><code><strong>doc.lastLine</strong>() → integer</code></dt>
<dd>Get the last line of the editor. This will
usually be <code>doc.lineCount() - 1</code>,
but for <a href="#linkedDoc_from">linked sub-views</a>,
it might return other values.</dd>
<dt id="getLineHandle"><code><strong>doc.getLineHandle</strong>(num: integer) → LineHandle</code></dt>
<dd>Fetches the line handle for the given line number.</dd>
<dt id="getLineNumber"><code><strong>doc.getLineNumber</strong>(handle: LineHandle) → integer</code></dt>
<dd>Given a line handle, returns the current position of that
line (or <code>null</code> when it is no longer in the
document).</dd>
<dt id="eachLine"><code><strong>doc.eachLine</strong>(f: (line: LineHandle))</code></dt>
<dt><code><strong>doc.eachLine</strong>(start: integer, end: integer, f: (line: LineHandle))</code></dt>
<dd>Iterate over the whole document, or if <code>start</code>
and <code>end</code> line numbers are given, the range
from <code>start</code> up to (not including) <code>end</code>,
and call <code>f</code> for each line, passing the line handle.
This is a faster way to visit a range of line handlers than
calling <a href="#getLineHandle"><code>getLineHandle</code></a>
for each of them. Note that line handles have
a <code>text</code> property containing the line's content (as a
string).</dd>
<dt id="markClean"><code><strong>doc.markClean</strong>()</code></dt>
<dd>Set the editor content as 'clean', a flag that it will
retain until it is edited, and which will be set again when such
an edit is undone again. Useful to track whether the content
needs to be saved. This function is deprecated in favor
of <a href="#changeGeneration"><code>changeGeneration</code></a>,
which allows multiple subsystems to track different notions of
cleanness without interfering.</dd>
<dt id="changeGeneration"><code><strong>doc.changeGeneration</strong>(?closeEvent: boolean) → integer</code></dt>
<dd>Returns a number that can later be passed
to <a href="#isClean"><code>isClean</code></a> to test whether
any edits were made (and not undone) in the meantime.
If <code>closeEvent</code> is true, the current history event
will be ‘closed’, meaning it can't be combined with further
changes (rapid typing or deleting events are typically
combined).</dd>
<dt id="isClean"><code><strong>doc.isClean</strong>(?generation: integer) → boolean</code></dt>
<dd>Returns whether the document is currently clean — not
modified since initialization or the last call
to <a href="#markClean"><code>markClean</code></a> if no
argument is passed, or since the matching call
to <a href="#changeGeneration"><code>changeGeneration</code></a>
if a generation value is given.</dd>
</dl>
<h3 id="api_selection">Cursor and selection methods</h3>
<dl>
<dt id="getSelection"><code><strong>doc.getSelection</strong>(?lineSep: string) → string</code></dt>
<dd>Get the currently selected code. Optionally pass a line
separator to put between the lines in the output. When multiple
selections are present, they are concatenated with instances
of <code>lineSep</code> in between.</dd>
<dt id="getSelections"><code><strong>doc.getSelections</strong>(?lineSep: string) → string</code></dt>
<dd>Returns an array containing a string for each selection,
representing the content of the selections.</dd>
<dt id="replaceSelection"><code><strong>doc.replaceSelection</strong>(replacement: string, ?select: string)</code></dt>
<dd>Replace the selection(s) with the given string. By default,
the new selection ends up after the inserted text. The
optional <code>select</code> argument can be used to change
this—passing <code>"around"</code> will cause the new text to be
selected, passing <code>"start"</code> will collapse the
selection to the start of the inserted text.</dd>
<dt id="replaceSelections"><code><strong>doc.replaceSelections</strong>(replacements: array&lt;string&gt;, ?select: string)</code></dt>
<dd>The length of the given array should be the same as the
number of active selections. Replaces the content of the
selections with the strings in the array.
The <code>select</code> argument works the same as
in <a href="#replaceSelection"><code>replaceSelection</code></a>.</dd>
<dt id="getCursor"><code><strong>doc.getCursor</strong>(?start: string) → {line, ch}</code></dt>
<dd>Retrieve one end of the <em>primary</em>
selection. <code>start</code> is a an optional string indicating
which end of the selection to return. It may
be <code>"from"</code>, <code>"to"</code>, <code>"head"</code>
(the side of the selection that moves when you press
shift+arrow), or <code>"anchor"</code> (the fixed side of the
selection). Omitting the argument is the same as
passing <code>"head"</code>. A <code>{line, ch}</code> object
will be returned.</dd>
<dt id="listSelections"><code><strong>doc.listSelections</strong>() → array&lt;{anchor, head}&gt;</code></dt>
<dd>Retrieves a list of all current selections. These will
always be sorted, and never overlap (overlapping selections are
merged). Each object in the array contains <code>anchor</code>
and <code>head</code> properties referring to <code>{line,
ch}</code> objects.</dd>
<dt id="somethingSelected"><code><strong>doc.somethingSelected</strong>() → boolean</code></dt>
<dd>Return true if any text is selected.</dd>
<dt id="setCursor"><code><strong>doc.setCursor</strong>(pos: {line, ch}|number, ?ch: number, ?options: object)</code></dt>
<dd>Set the cursor position. You can either pass a
single <code>{line, ch}</code> object, or the line and the
character as two separate parameters. Will replace all
selections with a single, empty selection at the given position.
The supported options are the same as for <a href="#setSelection"><code>setSelection</code></a>.</dd>
<dt id="setSelection"><code><strong>doc.setSelection</strong>(anchor: {line, ch}, ?head: {line, ch}, ?options: object)</code></dt>
<dd>Set a single selection range. <code>anchor</code>
and <code>head</code> should be <code>{line, ch}</code>
objects. <code>head</code> defaults to <code>anchor</code> when
not given. These options are supported:
<dl>
<dt id="selection_scroll"><code><strong>scroll</strong>: boolean</code></dt>
<dd>Determines whether the selection head should be scrolled
into view. Defaults to true.</dd>
<dt id="selection_origin"><code><strong>origin</strong>: string</code></dt>
<dd>Detemines whether the selection history event may be
merged with the previous one. When an origin starts with the
character <code>+</code>, and the last recorded selection had
the same origin and was similar (close
in <a href="#option_historyEventDelay">time</a>, both
collapsed or both non-collapsed), the new one will replace the
old one. When it starts with <code>*</code>, it will always
replace the previous event (if that had the same origin).
Built-in motion uses the <code>"+move"</code> origin.</dd>
<dt id="selection_bias"><code><strong>bias</strong>: number</code></dt>
<dd>Determine the direction into which the selection endpoints
should be adjusted when they fall inside
an <a href="#mark_atomic">atomic</a> range. Can be either -1
(backward) or 1 (forward). When not given, the bias will be
based on the relative position of the old selection—the editor
will try to move further away from that, to prevent getting
stuck.</dd>
</dl></dd>
<dt id="setSelections"><code><strong>doc.setSelections</strong>(ranges: array&lt;{anchor, head}&gt;, ?primary: integer, ?options: object)</code></dt>
<dd>Sets a new set of selections. There must be at least one
selection in the given array. When <code>primary</code> is a
number, it determines which selection is the primary one. When
it is not given, the primary index is taken from the previous
selection, or set to the last range if the previous selection
had less ranges than the new one. Supports the same options
as <a href="#setSelection"><code>setSelection</code></a>.</dd>
<dt id="addSelection"><code><strong>doc.addSelection</strong>(anchor: {line, ch}, ?head: {line, ch})</code></dt>
<dd>Adds a new selection to the existing set of selections, and
makes it the primary selection.</dd>
<dt id="extendSelection"><code><strong>doc.extendSelection</strong>(from: {line, ch}, ?to: {line, ch}, ?options: object)</code></dt>
<dd>Similar
to <a href="#setSelection"><code>setSelection</code></a>, but
will, if shift is held or
the <a href="#setExtending">extending</a> flag is set, move the
head of the selection while leaving the anchor at its current
place. <code>to</code> is optional, and can be passed to ensure
a region (for example a word or paragraph) will end up selected
(in addition to whatever lies between that region and the
current anchor). When multiple selections are present, all but
the primary selection will be dropped by this method.
Supports the same options as <a href="#setSelection"><code>setSelection</code></a>.</dd>
<dt id="extendSelections"><code><strong>doc.extendSelections</strong>(heads: array&lt;{line, ch}&gt;, ?options: object)</code></dt>
<dd>An equivalent
of <a href="#extendSelection"><code>extendSelection</code></a>
that acts on all selections at once.</dd>
<dt id="extendSelectionsBy"><code><strong>doc.extendSelectionsBy</strong>(f: function(range: {anchor, head}) → {anchor, head}), ?options: object)</code></dt>
<dd>Applies the given function to all existing selections, and
calls <a href="#extendSelections"><code>extendSelections</code></a>
on the result.</dd>
<dt id="setExtending"><code><strong>doc.setExtending</strong>(value: boolean)</code></dt>
<dd>Sets or clears the 'extending' flag, which acts similar to
the shift key, in that it will cause cursor movement and calls
to <a href="#extendSelection"><code>extendSelection</code></a>
to leave the selection anchor in place.</dd>
<dt id="getExtending"><code><strong>doc.getExtending</strong>() → boolean</code></dt>
<dd>Get the value of the 'extending' flag.</dd>
<dt id="hasFocus"><code><strong>cm.hasFocus</strong>() → boolean</code></dt>
<dd>Tells you whether the editor currently has focus.</dd>
<dt id="findPosH"><code><strong>cm.findPosH</strong>(start: {line, ch}, amount: integer, unit: string, visually: boolean) → {line, ch, ?hitSide: boolean}</code></dt>
<dd>Used to find the target position for horizontal cursor
motion. <code>start</code> is a <code>{line, ch}</code>
object, <code>amount</code> an integer (may be negative),
and <code>unit</code> one of the
string <code>"char"</code>, <code>"column"</code>,
or <code>"word"</code>. Will return a position that is produced
by moving <code>amount</code> times the distance specified
by <code>unit</code>. When <code>visually</code> is true, motion
in right-to-left text will be visual rather than logical. When
the motion was clipped by hitting the end or start of the
document, the returned value will have a <code>hitSide</code>
property set to true.</dd>
<dt id="findPosV"><code><strong>cm.findPosV</strong>(start: {line, ch}, amount: integer, unit: string) → {line, ch, ?hitSide: boolean}</code></dt>
<dd>Similar to <a href="#findPosH"><code>findPosH</code></a>,
but used for vertical motion. <code>unit</code> may
be <code>"line"</code> or <code>"page"</code>. The other
arguments and the returned value have the same interpretation as
they have in <code>findPosH</code>.</dd>
<dt id="findWordAt"><code><strong>cm.findWordAt</strong>(pos: {line, ch}) → {anchor: {line, ch}, head: {line, ch}}</code></dt>
<dd>Returns the start and end of the 'word' (the stretch of
letters, whitespace, or punctuation) at the given position.</dd>
</dl>
<h3 id="api_configuration">Configuration methods</h3>
<dl>
<dt id="setOption"><code><strong>cm.setOption</strong>(option: string, value: any)</code></dt>
<dd>Change the configuration of the editor. <code>option</code>
should the name of an <a href="#config">option</a>,
and <code>value</code> should be a valid value for that
option.</dd>
<dt id="getOption"><code><strong>cm.getOption</strong>(option: string) → any</code></dt>
<dd>Retrieves the current value of the given option for this
editor instance.</dd>
<dt id="addKeyMap"><code><strong>cm.addKeyMap</strong>(map: object, bottom: boolean)</code></dt>
<dd>Attach an additional <a href="#keymaps">key map</a> to the
editor. This is mostly useful for addons that need to register
some key handlers without trampling on
the <a href="#option_extraKeys"><code>extraKeys</code></a>
option. Maps added in this way have a higher precedence than
the <code>extraKeys</code>
and <a href="#option_keyMap"><code>keyMap</code></a> options,
and between them, the maps added earlier have a lower precedence
than those added later, unless the <code>bottom</code> argument
was passed, in which case they end up below other key maps added
with this method.</dd>
<dt id="removeKeyMap"><code><strong>cm.removeKeyMap</strong>(map: object)</code></dt>
<dd>Disable a keymap added
with <a href="#addKeyMap"><code>addKeyMap</code></a>. Either
pass in the key map object itself, or a string, which will be
compared against the <code>name</code> property of the active
key maps.</dd>
<dt id="addOverlay"><code><strong>cm.addOverlay</strong>(mode: string|object, ?options: object)</code></dt>
<dd>Enable a highlighting overlay. This is a stateless mini-mode
that can be used to add extra highlighting. For example,
the <a href="../demo/search.html">search addon</a> uses it to
highlight the term that's currently being
searched. <code>mode</code> can be a <a href="#option_mode">mode
spec</a> or a mode object (an object with
a <a href="#token"><code>token</code></a> method).
The <code>options</code> parameter is optional. If given, it
should be an object. Currently, only the <code>opaque</code>
option is recognized. This defaults to off, but can be given to
allow the overlay styling, when not <code>null</code>, to
override the styling of the base mode entirely, instead of the
two being applied together.</dd>
<dt id="removeOverlay"><code><strong>cm.removeOverlay</strong>(mode: string|object)</code></dt>
<dd>Pass this the exact value passed for the <code>mode</code>
parameter to <a href="#addOverlay"><code>addOverlay</code></a>,
or a string that corresponds to the <code>name</code> propery of
that value, to remove an overlay again.</dd>
<dt id="on"><code><strong>cm.on</strong>(type: string, func: (...args))</code></dt>
<dd>Register an event handler for the given event type (a
string) on the editor instance. There is also
a <code>CodeMirror.on(object, type, func)</code> version
that allows registering of events on any object.</dd>
<dt id="off"><code><strong>cm.off</strong>(type: string, func: (...args))</code></dt>
<dd>Remove an event handler on the editor instance. An
equivalent <code>CodeMirror.off(object, type,
func)</code> also exists.</dd>
</dl>
<h3 id="api_doc">Document management methods</h3>
<p id="Doc">Each editor is associated with an instance
of <code>CodeMirror.Doc</code>, its document. A document
represents the editor content, plus a selection, an undo history,
and a <a href="#option_mode">mode</a>. A document can only be
associated with a single editor at a time. You can create new
documents by calling the <code>CodeMirror.Doc(text, mode,
firstLineNumber)</code> constructor. The last two arguments are
optional and can be used to set a mode for the document and make
it start at a line number other than 0, respectively.</p>
<dl>
<dt id="getDoc"><code><strong>cm.getDoc</strong>() → Doc</code></dt>
<dd>Retrieve the currently active document from an editor.</dd>
<dt id="getEditor"><code><strong>doc.getEditor</strong>() → CodeMirror</code></dt>
<dd>Retrieve the editor associated with a document. May
return <code>null</code>.</dd>
<dt id="swapDoc"><code><strong>cm.swapDoc</strong>(doc: CodeMirror.Doc) → Doc</code></dt>
<dd>Attach a new document to the editor. Returns the old
document, which is now no longer associated with an editor.</dd>
<dt id="copy"><code><strong>doc.copy</strong>(copyHistory: boolean) → Doc</code></dt>
<dd>Create an identical copy of the given doc.
When <code>copyHistory</code> is true, the history will also be
copied. Can not be called directly on an editor.</dd>
<dt id="linkedDoc"><code><strong>doc.linkedDoc</strong>(options: object) → Doc</code></dt>
<dd>Create a new document that's linked to the target document.
Linked documents will stay in sync (changes to one are also
applied to the other) until <a href="#unlinkDoc">unlinked</a>.
These are the options that are supported:
<dl>
<dt id="linkedDoc_sharedHist"><code><strong>sharedHist</strong>: boolean</code></dt>
<dd>When turned on, the linked copy will share an undo
history with the original. Thus, something done in one of
the two can be undone in the other, and vice versa.</dd>
<dt id="linkedDoc_from"><code><strong>from</strong>: integer</code></dt>
<dt id="linkedDoc_to"><code><strong>to</strong>: integer</code></dt>
<dd>Can be given to make the new document a subview of the
original. Subviews only show a given range of lines. Note
that line coordinates inside the subview will be consistent
with those of the parent, so that for example a subview
starting at line 10 will refer to its first line as line 10,
not 0.</dd>
<dt id="linkedDoc_mode"><code><strong>mode</strong>: string|object</code></dt>
<dd>By default, the new document inherits the mode of the
parent. This option can be set to
a <a href="#option_mode">mode spec</a> to give it a
different mode.</dd>
</dl></dd>
<dt id="unlinkDoc"><code><strong>doc.unlinkDoc</strong>(doc: CodeMirror.Doc)</code></dt>
<dd>Break the link between two documents. After calling this,
changes will no longer propagate between the documents, and, if
they had a shared history, the history will become
separate.</dd>
<dt id="iterLinkedDocs"><code><strong>doc.iterLinkedDocs</strong>(function: (doc: CodeMirror.Doc, sharedHist: boolean))</code></dt>
<dd>Will call the given function for all documents linked to the
target document. It will be passed two arguments, the linked document
and a boolean indicating whether that document shares history
with the target.</dd>
</dl>
<h3 id="api_history">History-related methods</h3>
<dl>
<dt id="undo"><code><strong>doc.undo</strong>()</code></dt>
<dd>Undo one edit (if any undo events are stored).</dd>
<dt id="redo"><code><strong>doc.redo</strong>()</code></dt>
<dd>Redo one undone edit.</dd>
<dt id="undoSelection"><code><strong>doc.undoSelection</strong>()</code></dt>
<dd>Undo one edit or selection change.</dd>
<dt id="redoSelection"><code><strong>doc.redoSelection</strong>()</code></dt>
<dd>Redo one undone edit or selection change.</dd>
<dt id="historySize"><code><strong>doc.historySize</strong>() → {undo: integer, redo: integer}</code></dt>
<dd>Returns an object with <code>{undo, redo}</code> properties,
both of which hold integers, indicating the amount of stored
undo and redo operations.</dd>
<dt id="clearHistory"><code><strong>doc.clearHistory</strong>()</code></dt>
<dd>Clears the editor's undo history.</dd>
<dt id="getHistory"><code><strong>doc.getHistory</strong>() → object</code></dt>
<dd>Get a (JSON-serializeable) representation of the undo history.</dd>
<dt id="setHistory"><code><strong>doc.setHistory</strong>(history: object)</code></dt>
<dd>Replace the editor's undo history with the one provided,
which must be a value as returned
by <a href="#getHistory"><code>getHistory</code></a>. Note that
this will have entirely undefined results if the editor content
isn't also the same as it was when <code>getHistory</code> was
called.</dd>
</dl>
<h3 id="api_marker">Text-marking methods</h3>
<dl>
<dt id="markText"><code><strong>doc.markText</strong>(from: {line, ch}, to: {line, ch}, ?options: object) → TextMarker</code></dt>
<dd>Can be used to mark a range of text with a specific CSS
class name. <code>from</code> and <code>to</code> should
be <code>{line, ch}</code> objects. The <code>options</code>
parameter is optional. When given, it should be an object that
may contain the following configuration options:
<dl>
<dt id="mark_className"><code><strong>className</strong>: string</code></dt>
<dd>Assigns a CSS class to the marked stretch of text.</dd>
<dt id="mark_inclusiveLeft"><code><strong>inclusiveLeft</strong>: boolean</code></dt>
<dd>Determines whether
text inserted on the left of the marker will end up inside
or outside of it.</dd>
<dt id="mark_inclusiveRight"><code><strong>inclusiveRight</strong>: boolean</code></dt>
<dd>Like <code>inclusiveLeft</code>,
but for the right side.</dd>
<dt id="mark_atomic"><code><strong>atomic</strong>: boolean</code></dt>
<dd>Atomic ranges act as a single unit when cursor movement is
concerned—i.e. it is impossible to place the cursor inside of
them. In atomic ranges, <code>inclusiveLeft</code>
and <code>inclusiveRight</code> have a different meaning—they
will prevent the cursor from being placed respectively
directly before and directly after the range.</dd>
<dt id="mark_collapsed"><code><strong>collapsed</strong>: boolean</code></dt>
<dd>Collapsed ranges do not show up in the display. Setting a
range to be collapsed will automatically make it atomic.</dd>
<dt id="mark_clearOnEnter"><code><strong>clearOnEnter</strong>: boolean</code></dt>
<dd>When enabled, will cause the mark to clear itself whenever
the cursor enters its range. This is mostly useful for
text-replacement widgets that need to 'snap open' when the
user tries to edit them. The
<a href="#event_clear"><code>"clear"</code></a> event
fired on the range handle can be used to be notified when this
happens.</dd>
<dt id="mark_clearWhenEmpty"><code><strong>clearWhenEmpty</strong>: boolean</code></dt>
<dd>Determines whether the mark is automatically cleared when
it becomes empty. Default is true.</dd>
<dt id="mark_replacedWith"><code><strong>replacedWith</strong>: Element</code></dt>
<dd>Use a given node to display this range. Implies both
collapsed and atomic. The given DOM node <em>must</em> be an
inline element (as opposed to a block element).</dd>
<dt><code><strong>handleMouseEvents</strong>: boolean</code></dt>
<dd>When <code>replacedWith</code> is given, this determines
whether the editor will capture mouse and drag events
occurring in this widget. Default is false—the events will be
left alone for the default browser handler, or specific
handlers on the widget, to capture.</dd>
<dt id="mark_readOnly"><code><strong>readOnly</strong>: boolean</code></dt>
<dd>A read-only span can, as long as it is not cleared, not be
modified except by
calling <a href="#setValue"><code>setValue</code></a> to reset
the whole document. <em>Note:</em> adding a read-only span
currently clears the undo history of the editor, because
existing undo events being partially nullified by read-only
spans would corrupt the history (in the current
implementation).</dd>
<dt id="mark_addToHistory"><code><strong>addToHistory</strong>: boolean</code></dt>
<dd>When set to true (default is false), adding this marker
will create an event in the undo history that can be
individually undone (clearing the marker).</dd>
<dt id="mark_startStyle"><code><strong>startStyle</strong>: string</code></dt><dd>Can be used to specify
an extra CSS class to be applied to the leftmost span that
is part of the marker.</dd>
<dt id="mark_endStyle"><code><strong>endStyle</strong>: string</code></dt><dd>Equivalent
to <code>startStyle</code>, but for the rightmost span.</dd>
<dt id="mark_css"><code><strong>css</strong>: string</code></dt>
<dd>A string of CSS to be applied to the covered text. For example <code>"color: #fe3"</code>.</dd>
<dt id="mark_title"><code><strong>title</strong>:
string</code></dt><dd>When given, will give the nodes created
for this span a HTML <code>title</code> attribute with the
given value.</dd>
<dt id="mark_shared"><code><strong>shared</strong>: boolean</code></dt><dd>When the
target document is <a href="#linkedDoc">linked</a> to other
documents, you can set <code>shared</code> to true to make the
marker appear in all documents. By default, a marker appears
only in its target document.</dd>
</dl>
The method will return an object that represents the marker
(with constructor <code>CodeMirror.TextMarker</code>), which
exposes three methods:
<code><strong>clear</strong>()</code>, to remove the mark,
<code><strong>find</strong>()</code>, which returns
a <code>{from, to}</code> object (both holding document
positions), indicating the current position of the marked range,
or <code>undefined</code> if the marker is no longer in the
document, and finally <code><strong>changed</strong>()</code>,
which you can call if you've done something that might change
the size of the marker (for example changing the content of
a <a href="#mark_replacedWith"><code>replacedWith</code></a>
node), and want to cheaply update the display.</dd>
<dt id="setBookmark"><code><strong>doc.setBookmark</strong>(pos: {line, ch}, ?options: object) → TextMarker</code></dt>
<dd>Inserts a bookmark, a handle that follows the text around it
as it is being edited, at the given position. A bookmark has two
methods <code>find()</code> and <code>clear()</code>. The first
returns the current position of the bookmark, if it is still in
the document, and the second explicitly removes the bookmark.
The options argument is optional. If given, the following
properties are recognized:
<dl>
<dt><code><strong>widget</strong>: Element</code></dt><dd>Can be used to display a DOM
node at the current location of the bookmark (analogous to
the <a href="#mark_replacedWith"><code>replacedWith</code></a>
option to <a href="#markText"><code>markText</code></a>).</dd>
<dt><code><strong>insertLeft</strong>: boolean</code></dt><dd>By default, text typed
when the cursor is on top of the bookmark will end up to the
right of the bookmark. Set this option to true to make it go
to the left instead.</dd>
<dt><code><strong>shared</strong>: boolean</code></dt><dd>See
the corresponding <a href="#mark_shared">option</a>
to <code>markText</code>.</dd>
<dt><code><strong>handleMouseEvents</strong>: boolean</code></dt>
<dd>As with <a href="#markText"><code>markText</code></a>,
this determines whether mouse events on the widget inserted
for this bookmark are handled by CodeMirror. The default is
false.</dd>
</dl></dd>
<dt id="findMarks"><code><strong>doc.findMarks</strong>(from: {line, ch}, to: {line, ch}) → array&lt;TextMarker&gt;</code></dt>
<dd>Returns an array of all the bookmarks and marked ranges
found between the given positions.</dd>
<dt id="findMarksAt"><code><strong>doc.findMarksAt</strong>(pos: {line, ch}) → array&lt;TextMarker&gt;</code></dt>
<dd>Returns an array of all the bookmarks and marked ranges
present at the given position.</dd>
<dt id="getAllMarks"><code><strong>doc.getAllMarks</strong>() → array&lt;TextMarker&gt;</code></dt>
<dd>Returns an array containing all marked ranges in the document.</dd>
</dl>
<h3 id="api_decoration">Widget, gutter, and decoration methods</h3>
<dl>
<dt id="setGutterMarker"><code><strong>cm.setGutterMarker</strong>(line: integer|LineHandle, gutterID: string, value: Element) → LineHandle</code></dt>
<dd>Sets the gutter marker for the given gutter (identified by
its CSS class, see
the <a href="#option_gutters"><code>gutters</code></a> option)
to the given value. Value can be either <code>null</code>, to
clear the marker, or a DOM element, to set it. The DOM element
will be shown in the specified gutter next to the specified
line.</dd>
<dt id="clearGutter"><code><strong>cm.clearGutter</strong>(gutterID: string)</code></dt>
<dd>Remove all gutter markers in
the <a href="#option_gutters">gutter</a> with the given ID.</dd>
<dt id="addLineClass"><code><strong>doc.addLineClass</strong>(line: integer|LineHandle, where: string, class: string) → LineHandle</code></dt>
<dd>Set a CSS class name for the given line. <code>line</code>
can be a number or a line handle. <code>where</code> determines
to which element this class should be applied, can can be one
of <code>"text"</code> (the text element, which lies in front of
the selection), <code>"background"</code> (a background element
that will be behind the selection), <code>"gutter"</code> (the
line's gutter space), or <code>"wrap"</code> (the wrapper node
that wraps all of the line's elements, including gutter
elements). <code>class</code> should be the name of the class to
apply.</dd>
<dt id="removeLineClass"><code><strong>doc.removeLineClass</strong>(line: integer|LineHandle, where: string, class: string) → LineHandle</code></dt>
<dd>Remove a CSS class from a line. <code>line</code> can be a
line handle or number. <code>where</code> should be one
of <code>"text"</code>, <code>"background"</code>,
or <code>"wrap"</code>
(see <a href="#addLineClass"><code>addLineClass</code></a>). <code>class</code>
can be left off to remove all classes for the specified node, or
be a string to remove only a specific class.</dd>
<dt id="lineInfo"><code><strong>cm.lineInfo</strong>(line: integer|LineHandle) → object</code></dt>
<dd>Returns the line number, text content, and marker status of
the given line, which can be either a number or a line handle.
The returned object has the structure <code>{line, handle, text,
gutterMarkers, textClass, bgClass, wrapClass, widgets}</code>,
where <code>gutterMarkers</code> is an object mapping gutter IDs
to marker elements, and <code>widgets</code> is an array
of <a href="#addLineWidget">line widgets</a> attached to this
line, and the various class properties refer to classes added
with <a href="#addLineClass"><code>addLineClass</code></a>.</dd>
<dt id="addWidget"><code><strong>cm.addWidget</strong>(pos: {line, ch}, node: Element, scrollIntoView: boolean)</code></dt>
<dd>Puts <code>node</code>, which should be an absolutely
positioned DOM node, into the editor, positioned right below the
given <code>{line, ch}</code> position.
When <code>scrollIntoView</code> is true, the editor will ensure
that the entire node is visible (if possible). To remove the
widget again, simply use DOM methods (move it somewhere else, or
call <code>removeChild</code> on its parent).</dd>
<dt id="addLineWidget"><code><strong>doc.addLineWidget</strong>(line: integer|LineHandle, node: Element, ?options: object) → LineWidget</code></dt>
<dd>Adds a line widget, an element shown below a line, spanning
the whole of the editor's width, and moving the lines below it
downwards. <code>line</code> should be either an integer or a
line handle, and <code>node</code> should be a DOM node, which
will be displayed below the given line. <code>options</code>,
when given, should be an object that configures the behavior of
the widget. The following options are supported (all default to
false):
<dl>
<dt><code><strong>coverGutter</strong>: boolean</code></dt>
<dd>Whether the widget should cover the gutter.</dd>
<dt><code><strong>noHScroll</strong>: boolean</code></dt>
<dd>Whether the widget should stay fixed in the face of
horizontal scrolling.</dd>
<dt><code><strong>above</strong>: boolean</code></dt>
<dd>Causes the widget to be placed above instead of below
the text of the line.</dd>
<dt><code><strong>handleMouseEvents</strong>: boolean</code></dt>
<dd>Determines whether the editor will capture mouse and
drag events occurring in this widget. Default is false—the
events will be left alone for the default browser handler,
or specific handlers on the widget, to capture.</dd>
<dt><code><strong>insertAt</strong>: integer</code></dt>
<dd>By default, the widget is added below other widgets for
the line. This option can be used to place it at a different
position (zero for the top, N to put it after the Nth other
widget). Note that this only has effect once, when the
widget is created.
</dl>
Note that the widget node will become a descendant of nodes with
CodeMirror-specific CSS classes, and those classes might in some
cases affect it. This method returns an object that represents
the widget placement. It'll have a <code>line</code> property
pointing at the line handle that it is associated with, and the following methods:
<dl>
<dt id="widget_clear"><code><strong>clear</strong>()</code></dt><dd>Removes the widget.</dd>
<dt id="widget_changed"><code><strong>changed</strong>()</code></dt><dd>Call
this if you made some change to the widget's DOM node that
might affect its height. It'll force CodeMirror to update
the height of the line that contains the widget.</dd>
</dl>
</dd>
</dl>
<h3 id="api_sizing">Sizing, scrolling and positioning methods</h3>
<dl>
<dt id="setSize"><code><strong>cm.setSize</strong>(width: number|string, height: number|string)</code></dt>
<dd>Programatically set the size of the editor (overriding the
applicable <a href="#css-resize">CSS
rules</a>). <code>width</code> and <code>height</code>
can be either numbers (interpreted as pixels) or CSS units
(<code>"100%"</code>, for example). You can
pass <code>null</code> for either of them to indicate that that
dimension should not be changed.</dd>
<dt id="scrollTo"><code><strong>cm.scrollTo</strong>(x: number, y: number)</code></dt>
<dd>Scroll the editor to a given (pixel) position. Both
arguments may be left as <code>null</code>
or <code>undefined</code> to have no effect.</dd>
<dt id="getScrollInfo"><code><strong>cm.getScrollInfo</strong>() → {left, top, width, height, clientWidth, clientHeight}</code></dt>
<dd>Get an <code>{left, top, width, height, clientWidth,
clientHeight}</code> object that represents the current scroll
position, the size of the scrollable area, and the size of the
visible area (minus scrollbars).</dd>
<dt id="scrollIntoView"><code><strong>cm.scrollIntoView</strong>(what: {line, ch}|{left, top, right, bottom}|{from, to}|null, ?margin: number)</code></dt>
<dd>Scrolls the given position into view. <code>what</code> may
be <code>null</code> to scroll the cursor into view,
a <code>{line, ch}</code> position to scroll a character into
view, a <code>{left, top, right, bottom}</code> pixel range (in
editor-local coordinates), or a range <code>{from, to}</code>
containing either two character positions or two pixel squares.
The <code>margin</code> parameter is optional. When given, it
indicates the amount of vertical pixels around the given area
that should be made visible as well.</dd>
<dt id="cursorCoords"><code><strong>cm.cursorCoords</strong>(where: boolean|{line, ch}, mode: string) → {left, top, bottom}</code></dt>
<dd>Returns an <code>{left, top, bottom}</code> object
containing the coordinates of the cursor position.
If <code>mode</code> is <code>"local"</code>, they will be
relative to the top-left corner of the editable document. If it
is <code>"page"</code> or not given, they are relative to the
top-left corner of the page. If <code>mode</code>
is <code>"window"</code>, the coordinates are relative to the
top-left corner of the currently visible (scrolled)
window. <code>where</code> can be a boolean indicating whether
you want the start (<code>true</code>) or the end
(<code>false</code>) of the selection, or, if a <code>{line,
ch}</code> object is given, it specifies the precise position at
which you want to measure.</dd>
<dt id="charCoords"><code><strong>cm.charCoords</strong>(pos: {line, ch}, ?mode: string) → {left, right, top, bottom}</code></dt>
<dd>Returns the position and dimensions of an arbitrary
character. <code>pos</code> should be a <code>{line, ch}</code>
object. This differs from <code>cursorCoords</code> in that
it'll give the size of the whole character, rather than just the
position that the cursor would have when it would sit at that
position.</dd>
<dt id="coordsChar"><code><strong>cm.coordsChar</strong>(object: {left, top}, ?mode: string) → {line, ch}</code></dt>
<dd>Given an <code>{left, top}</code> object, returns
the <code>{line, ch}</code> position that corresponds to it. The
optional <code>mode</code> parameter determines relative to what
the coordinates are interpreted. It may
be <code>"window"</code>, <code>"page"</code> (the default),
or <code>"local"</code>.</dd>
<dt id="lineAtHeight"><code><strong>cm.lineAtHeight</strong>(height: number, ?mode: string) → number</code></dt>
<dd>Computes the line at the given pixel
height. <code>mode</code> can be one of the same strings
that <a href="#coordsChar"><code>coordsChar</code></a>
accepts.</dd>
<dt id="heightAtLine"><code><strong>cm.heightAtLine</strong>(line: integer|LineHandle, ?mode: string) → number</code></dt>
<dd>Computes the height of the top of a line, in the coordinate
system specified by <code>mode</code>
(see <a href="#coordsChar"><code>coordsChar</code></a>), which
defaults to <code>"page"</code>. When a line below the bottom of
the document is specified, the returned value is the bottom of
the last line in the document.</dd>
<dt id="defaultTextHeight"><code><strong>cm.defaultTextHeight</strong>() → number</code></dt>
<dd>Returns the line height of the default font for the editor.</dd>
<dt id="defaultCharWidth"><code><strong>cm.defaultCharWidth</strong>() → number</code></dt>
<dd>Returns the pixel width of an 'x' in the default font for
the editor. (Note that for non-monospace fonts, this is mostly
useless, and even for monospace fonts, non-ascii characters
might have a different width).</dd>
<dt id="getViewport"><code><strong>cm.getViewport</strong>() → {from: number, to: number}</code></dt>
<dd>Returns a <code>{from, to}</code> object indicating the
start (inclusive) and end (exclusive) of the currently rendered
part of the document. In big documents, when most content is
scrolled out of view, CodeMirror will only render the visible
part, and a margin around it. See also
the <a href="#event_viewportChange"><code>viewportChange</code></a>
event.</dd>
<dt id="refresh"><code><strong>cm.refresh</strong>()</code></dt>
<dd>If your code does something to change the size of the editor
element (window resizes are already listened for), or unhides
it, you should probably follow up by calling this method to
ensure CodeMirror is still looking as intended.</dd>
</dl>
<h3 id="api_mode">Mode, state, and token-related methods</h3>
<p>When writing language-aware functionality, it can often be
useful to hook into the knowledge that the CodeMirror language
mode has. See <a href="#modeapi">the section on modes</a> for a
more detailed description of how these work.</p>
<dl>
<dt id="getMode"><code><strong>doc.getMode</strong>() → object</code></dt>
<dd>Gets the (outer) mode object for the editor. Note that this
is distinct from <code>getOption("mode")</code>, which gives you
the mode specification, rather than the resolved, instantiated
<a href="#defineMode">mode object</a>.</dd>
<dt id="getModeAt"><code><strong>doc.getModeAt</strong>(pos: {line, ch}) → object</code></dt>
<dd>Gets the inner mode at a given position. This will return
the same as <a href="#getMode"><code>getMode</code></a> for
simple modes, but will return an inner mode for nesting modes
(such as <code>htmlmixed</code>).</dd>
<dt id="getTokenAt"><code><strong>cm.getTokenAt</strong>(pos: {line, ch}, ?precise: boolean) → object</code></dt>
<dd>Retrieves information about the token the current mode found
before the given position (a <code>{line, ch}</code> object). The
returned object has the following properties:
<dl>
<dt><code><strong>start</strong></code></dt><dd>The character (on the given line) at which the token starts.</dd>
<dt><code><strong>end</strong></code></dt><dd>The character at which the token ends.</dd>
<dt><code><strong>string</strong></code></dt><dd>The token's string.</dd>
<dt><code><strong>type</strong></code></dt><dd>The token type the mode assigned
to the token, such as <code>"keyword"</code>
or <code>"comment"</code> (may also be null).</dd>
<dt><code><strong>state</strong></code></dt><dd>The mode's state at the end of this token.</dd>
</dl>
If <code>precise</code> is true, the token will be guaranteed to be accurate based on recent edits. If false or
not specified, the token will use cached state information, which will be faster but might not be accurate if
edits were recently made and highlighting has not yet completed.
</dd>
<dt id="getLineTokens"><code><strong>cm.getLineTokens</strong>(line: integer, ?precise: boolean) → array&lt;{start, end, string, type, state}&gt;</code></dt>
<dd>This is similar
to <a href="#getTokenAt"><code>getTokenAt</code></a>, but
collects all tokens for a given line into an array. It is much
cheaper than repeatedly calling <code>getTokenAt</code>, which
re-parses the part of the line before the token for every call.</dd>
<dt id="getTokenTypeAt"><code><strong>cm.getTokenTypeAt</strong>(pos: {line, ch}) → string</code></dt>
<dd>This is a (much) cheaper version
of <a href="#getTokenAt"><code>getTokenAt</code></a> useful for
when you just need the type of the token at a given position,
and no other information. Will return <code>null</code> for
unstyled tokens, and a string, potentially containing multiple
space-separated style names, otherwise.</dd>
<dt id="getHelpers"><code><strong>cm.getHelpers</strong>(pos: {line, ch}, type: string) → array&lt;helper&gt;</code></dt>
<dd>Fetch the set of applicable helper values for the given
position. Helpers provide a way to look up functionality
appropriate for a mode. The <code>type</code> argument provides
the helper namespace (see
<a href="#registerHelper"><code>registerHelper</code></a>), in
which the values will be looked up. When the mode itself has a
property that corresponds to the <code>type</code>, that
directly determines the keys that are used to look up the helper
values (it may be either a single string, or an array of
strings). Failing that, the mode's <code>helperType</code>
property and finally the mode's name are used.</dd>
<dd>For example, the JavaScript mode has a
property <code>fold</code> containing <code>"brace"</code>. When
the <code>brace-fold</code> addon is loaded, that defines a
helper named <code>brace</code> in the <code>fold</code>
namespace. This is then used by
the <a href="#addon_foldcode"><code>foldcode</code></a> addon to
figure out that it can use that folding function to fold
JavaScript code.</dd>
<dd>When any <a href="#registerGlobalHelper">'global'</a>
helpers are defined for the given namespace, their predicates
are called on the current mode and editor, and all those that
declare they are applicable will also be added to the array that
is returned.</dd>
<dt id="getHelper"><code><strong>cm.getHelper</strong>(pos: {line, ch}, type: string) → helper</code></dt>
<dd>Returns the first applicable helper value.
See <a href="#getHelpers"><code>getHelpers</code></a>.</dd>
<dt id="getStateAfter"><code><strong>cm.getStateAfter</strong>(?line: integer, ?precise: boolean) → object</code></dt>
<dd>Returns the mode's parser state, if any, at the end of the
given line number. If no line number is given, the state at the
end of the document is returned. This can be useful for storing
parsing errors in the state, or getting other kinds of
contextual information for a line. <code>precise</code> is defined
as in <code>getTokenAt()</code>.</dd>
</dl>
<h3 id="api_misc">Miscellaneous methods</h3>
<dl>
<dt id="operation"><code><strong>cm.operation</strong>(func: () → any) → any</code></dt>
<dd>CodeMirror internally buffers changes and only updates its
DOM structure after it has finished performing some operation.
If you need to perform a lot of operations on a CodeMirror
instance, you can call this method with a function argument. It
will call the function, buffering up all changes, and only doing
the expensive update after the function returns. This can be a
lot faster. The return value from this method will be the return
value of your function.</dd>
<dt id="indentLine"><code><strong>cm.indentLine</strong>(line: integer, ?dir: string|integer)</code></dt>
<dd>Adjust the indentation of the given line. The second
argument (which defaults to <code>"smart"</code>) may be one of:
<dl>
<dt><code><strong>"prev"</strong></code></dt>
<dd>Base indentation on the indentation of the previous line.</dd>
<dt><code><strong>"smart"</strong></code></dt>
<dd>Use the mode's smart indentation if available, behave
like <code>"prev"</code> otherwise.</dd>
<dt><code><strong>"add"</strong></code></dt>
<dd>Increase the indentation of the line by
one <a href="#option_indentUnit">indent unit</a>.</dd>
<dt><code><strong>"subtract"</strong></code></dt>
<dd>Reduce the indentation of the line.</dd>
<dt><code><strong>&lt;integer></strong></code></dt>
<dd>Add (positive number) or reduce (negative number) the
indentation by the given amount of spaces.</dd>
</dl></dd>
<dt id="toggleOverwrite"><code><strong>cm.toggleOverwrite</strong>(?value: bool)</code></dt>
<dd>Switches between overwrite and normal insert mode (when not
given an argument), or sets the overwrite mode to a specific
state (when given an argument).</dd>
<dt id="execCommand"><code><strong>cm.execCommand</strong>(name: string)</code></dt>
<dd>Runs the <a href="#commands">command</a> with the given name on the editor.</dd>
<dt id="posFromIndex"><code><strong>doc.posFromIndex</strong>(index: integer) → {line, ch}</code></dt>
<dd>Calculates and returns a <code>{line, ch}</code> object for a
zero-based <code>index</code> who's value is relative to the start of the
editor's text. If the <code>index</code> is out of range of the text then
the returned object is clipped to start or end of the text
respectively.</dd>
<dt id="indexFromPos"><code><strong>doc.indexFromPos</strong>(object: {line, ch}) → integer</code></dt>
<dd>The reverse of <a href="#posFromIndex"><code>posFromIndex</code></a>.</dd>
<dt id="focus"><code><strong>cm.focus</strong>()</code></dt>
<dd>Give the editor focus.</dd>
<dt id="getInputField"><code><strong>cm.getInputField</strong>() → Element</code></dt>
<dd>Returns the input field for the editor. Will be a textarea
or an editable div, depending on the value of
the <a href="#option_inputStyle"><code>inputStyle</code></a>
option.</dd>
<dt id="getWrapperElement"><code><strong>cm.getWrapperElement</strong>() → Element</code></dt>
<dd>Returns the DOM node that represents the editor, and
controls its size. Remove this from your tree to delete an
editor instance.</dd>
<dt id="getScrollerElement"><code><strong>cm.getScrollerElement</strong>() → Element</code></dt>
<dd>Returns the DOM node that is responsible for the scrolling
of the editor.</dd>
<dt id="getGutterElement"><code><strong>cm.getGutterElement</strong>() → Element</code></dt>
<dd>Fetches the DOM node that contains the editor gutters.</dd>
</dl>
<h3 id="api_static">Static properties</h3>
<p>The <code>CodeMirror</code> object itself provides
several useful properties.</p>
<dl>
<dt id="version"><code><strong>CodeMirror.version</strong>: string</code></dt>
<dd>It contains a string that indicates the version of the
library. This is a triple of
integers <code>"major.minor.patch"</code>,
where <code>patch</code> is zero for releases, and something
else (usually one) for dev snapshots.</dd>
<dt id="fromTextArea"><code><strong>CodeMirror.fromTextArea</strong>(textArea: TextAreaElement, ?config: object)</code></dt>
<dd>
The method provides another way to initialize an editor. It
takes a textarea DOM node as first argument and an optional
configuration object as second. It will replace the textarea
with a CodeMirror instance, and wire up the form of that
textarea (if any) to make sure the editor contents are put
into the textarea when the form is submitted. The text in the
textarea will provide the content for the editor. A CodeMirror
instance created this way has three additional methods:
<dl>
<dt id="save"><code><strong>cm.save</strong>()</code></dt>
<dd>Copy the content of the editor into the textarea.</dd>
<dt id="toTextArea"><code><strong>cm.toTextArea</strong>()</code></dt>
<dd>Remove the editor, and restore the original textarea (with
the editor's current content).</dd>
<dt id="getTextArea"><code><strong>cm.getTextArea</strong>() → TextAreaElement</code></dt>
<dd>Returns the textarea that the instance was based on.</dd>
</dl>
</dd>
<dt id="defaults"><code><strong>CodeMirror.defaults</strong>: object</code></dt>
<dd>An object containing default values for
all <a href="#config">options</a>. You can assign to its
properties to modify defaults (though this won't affect editors
that have already been created).</dd>
<dt id="defineExtension"><code><strong>CodeMirror.defineExtension</strong>(name: string, value: any)</code></dt>
<dd>If you want to define extra methods in terms of the
CodeMirror API, it is possible to
use <code>defineExtension</code>. This will cause the given
value (usually a method) to be added to all CodeMirror instances
created from then on.</dd>
<dt id="defineDocExtension"><code><strong>CodeMirror.defineDocExtension</strong>(name: string, value: any)</code></dt>
<dd>Like <a href="#defineExtenstion"><code>defineExtension</code></a>,
but the method will be added to the interface
for <a href="#Doc"><code>Doc</code></a> objects instead.</dd>
<dt id="defineOption"><code><strong>CodeMirror.defineOption</strong>(name: string,
default: any, updateFunc: function)</code></dt>
<dd>Similarly, <code>defineOption</code> can be used to define new options for
CodeMirror. The <code>updateFunc</code> will be called with the
editor instance and the new value when an editor is initialized,
and whenever the option is modified
through <a href="#setOption"><code>setOption</code></a>.</dd>
<dt id="defineInitHook"><code><strong>CodeMirror.defineInitHook</strong>(func: function)</code></dt>
<dd>If your extention just needs to run some
code whenever a CodeMirror instance is initialized,
use <code>CodeMirror.defineInitHook</code>. Give it a function as
its only argument, and from then on, that function will be called
(with the instance as argument) whenever a new CodeMirror instance
is initialized.</dd>
<dt id="registerHelper"><code><strong>CodeMirror.registerHelper</strong>(type: string, name: string, value: helper)</code></dt>
<dd>Registers a helper value with the given <code>name</code> in
the given namespace (<code>type</code>). This is used to define
functionality that may be looked up by mode. Will create (if it
doesn't already exist) a property on the <code>CodeMirror</code>
object for the given <code>type</code>, pointing to an object
that maps names to values. I.e. after
doing <code>CodeMirror.registerHelper("hint", "foo",
myFoo)</code>, the value <code>CodeMirror.hint.foo</code> will
point to <code>myFoo</code>.</dd>
<dt id="registerGlobalHelper"><code><strong>CodeMirror.registerGlobalHelper</strong>(type: string, name: string, predicate: fn(mode, CodeMirror), value: helper)</code></dt>
<dd>Acts
like <a href="#registerHelper"><code>registerHelper</code></a>,
but also registers this helper as 'global', meaning that it will
be included by <a href="#getHelpers"><code>getHelpers</code></a>
whenever the given <code>predicate</code> returns true when
called with the local mode and editor.</dd>
<dt id="Pos"><code><strong>CodeMirror.Pos</strong>(line: integer, ?ch: integer)</code></dt>
<dd>A constructor for the <code>{line, ch}</code> objects that
are used to represent positions in editor documents.</dd>
<dt id="changeEnd"><code><strong>CodeMirror.changeEnd</strong>(change: object) → {line, ch}</code></dt>
<dd>Utility function that computes an end position from a change
(an object with <code>from</code>, <code>to</code>,
and <code>text</code> properties, as passed to
various <a href="#event_change">event handlers</a>). The
returned position will be the end of the changed
range, <em>after</em> the change is applied.</dd>
</dl>
</section>
<section id=addons>
<h2 id="addons">Addons</h2>
<p>The <code>addon</code> directory in the distribution contains a
number of reusable components that implement extra editor
functionality (on top of extension functions
like <a href="#defineOption"><code>defineOption</code></a>, <a href="#defineExtension"><code>defineExtension</code></a>,
and <a href="#registerHelper"><code>registerHelper</code></a>). In
brief, they are:</p>
<dl>
<dt id="addon_dialog"><a href="../addon/dialog/dialog.js"><code>dialog/dialog.js</code></a></dt>
<dd>Provides a very simple way to query users for text input.
Adds the <strong><code>openDialog(template, callback, options) →
closeFunction</code></strong> method to CodeMirror instances,
which can be called with an HTML fragment or a detached DOM
node that provides the prompt (should include an <code>input</code>
or <code>button</code> tag), and a callback function that is called
when the user presses enter. It returns a function <code>closeFunction</code>
which, if called, will close the dialog immediately.
<strong><code>openDialog</code></strong> takes the following options:
<dl>
<dt><code><strong>closeOnEnter</strong></code>:</dt>
<dd>If true, the dialog will be closed when the user presses
enter in the input. Defaults to <code>true</code>.</dd>
<dt><code><strong>onKeyDown</strong></code>:</dt>
<dd>An event handler of the signature <code>(event, value, closeFunction)</code>
that will be called whenever <code>keydown</code> fires in the
dialog's input. If your callback returns <code>true</code>,
the dialog will not do any further processing of the event.</dd>
<dt><code><strong>onKeyUp</strong></code>:</dt>
<dd>Same as <code>onKeyDown</code> but for the
<code>keyup</code> event.</dd>
<dt><code><strong>onInput</strong></code>:</dt>
<dd>Same as <code>onKeyDown</code> but for the
<code>input</code> event.</dd>
<dt><code><strong>onClose</strong></code>:</dt>
<dd>A callback of the signature <code>(dialogInstance)</code>
that will be called after the dialog has been closed and
removed from the DOM. No return value.</dd>
</dl>
<p>Also adds an <strong><code>openNotification(template, options) →
closeFunction</code></strong> function that simply shows an HTML
fragment as a notification at the top of the editor. It takes a
single option: <code>duration</code>, the amount of time after
which the notification will be automatically closed. If <code>
duration</code> is zero, the dialog will not be closed automatically.</p>
<p>Depends on <code>addon/dialog/dialog.css</code>.</p></dd>
<dt id="addon_searchcursor"><a href="../addon/search/searchcursor.js"><code>search/searchcursor.js</code></a></dt>
<dd>Adds the <code>getSearchCursor(query, start, caseFold) →
cursor</code> method to CodeMirror instances, which can be used
to implement search/replace functionality. <code>query</code>
can be a regular expression or a string (only strings will match
across lines—if they contain newlines). <code>start</code>
provides the starting position of the search. It can be
a <code>{line, ch}</code> object, or can be left off to default
to the start of the document. <code>caseFold</code> is only
relevant when matching a string. It will cause the search to be
case-insensitive. A search cursor has the following methods:
<dl>
<dt><code><strong>findNext</strong>() → boolean</code></dt>
<dt><code><strong>findPrevious</strong>() → boolean</code></dt>
<dd>Search forward or backward from the current position.
The return value indicates whether a match was found. If
matching a regular expression, the return value will be the
array returned by the <code>match</code> method, in case you
want to extract matched groups.</dd>
<dt><code><strong>from</strong>() → {line, ch}</code></dt>
<dt><code><strong>to</strong>() → {line, ch}</code></dt>
<dd>These are only valid when the last call
to <code>findNext</code> or <code>findPrevious</code> did
not return false. They will return <code>{line, ch}</code>
objects pointing at the start and end of the match.</dd>
<dt><code><strong>replace</strong>(text: string, ?origin: string)</code></dt>
<dd>Replaces the currently found match with the given text
and adjusts the cursor position to reflect the
replacement.</dd>
</dl></dd>
<dt id="addon_search"><a href="../addon/search/search.js"><code>search/search.js</code></a></dt>
<dd>Implements the search commands. CodeMirror has keys bound to
these by default, but will not do anything with them unless an
implementation is provided. Depends
on <code>searchcursor.js</code>, and will make use
of <a href="#addon_dialog"><code>openDialog</code></a> when
available to make prompting for search queries less ugly.</dd>
<dt id="addon_matchesonscrollbar"><a href="../addon/search/matchesonscrollbar.js"><code>search/matchesonscrollbar.js</code></a></dt>
<dd>Adds a <code>showMatchesOnScrollbar</code> method to editor
instances, which should be given a query (string or regular
expression), optionally a case-fold flag (only applicable for
strings), and optionally a class name (defaults
to <code>CodeMirror-search-match</code>) as arguments. When
called, matches of the given query will be displayed on the
editor's vertical scrollbar. The method returns an object with
a <code>clear</code> method that can be called to remove the
matches. Depends on
the <a href="#addon_annotatescrollbar"><code>annotatescrollbar</code></a>
addon, and
the <a href="../addon/search/matchesonscrollbar.css"><code>matchesonscrollbar.css</code></a>
file provides a default (transparent yellowish) definition of
the CSS class applied to the matches. Note that the matches are
only perfectly aligned if your scrollbar does not have buttons
at the top and bottom. You can use
the <a href="#addon_simplescrollbars"><code>simplescrollbar</code></a>
addon to make sure of this. If this addon is loaded,
the <a href="#addon_search"><code>search</code></a> addon will
automatically use it.</dd>
<dt id="addon_matchbrackets"><a href="../addon/edit/matchbrackets.js"><code>edit/matchbrackets.js</code></a></dt>
<dd>Defines an option <code>matchBrackets</code> which, when set
to true, causes matching brackets to be highlighted whenever the
cursor is next to them. It also adds a
method <code>matchBrackets</code> that forces this to happen
once, and a method <code>findMatchingBracket</code> that can be
used to run the bracket-finding algorithm that this uses
internally.</dd>
<dt id="addon_closebrackets"><a href="../addon/edit/closebrackets.js"><code>edit/closebrackets.js</code></a></dt>
<dd>Defines an option <code>autoCloseBrackets</code> that will
auto-close brackets and quotes when typed. By default, it'll
auto-close <code>()[]{}''""</code>, but you can pass it a string
similar to that (containing pairs of matching characters), or an
object with <code>pairs</code> and
optionally <code>explode</code> properties to customize
it. <code>explode</code> should be a similar string that gives
the pairs of characters that, when enter is pressed between
them, should have the second character also moved to its own
line. <a href="../demo/closebrackets.html">Demo here</a>.</dd>
<dt id="addon_matchtags"><a href="../addon/edit/matchtags.js"><code>edit/matchtags.js</code></a></dt>
<dd>Defines an option <code>matchTags</code> that, when enabled,
will cause the tags around the cursor to be highlighted (using
the <code>CodeMirror-matchingtag</code> class). Also
defines
a <a href="#commands">command</a> <code>toMatchingTag</code>,
which you can bind a key to in order to jump to the tag mathing
the one under the cursor. Depends on
the <code>addon/fold/xml-fold.js</code>
addon. <a href="../demo/matchtags.html">Demo here.</a></dd>
<dt id="addon_trailingspace"><a href="../addon/edit/trailingspace.js"><code>edit/trailingspace.js</code></a></dt>
<dd>Adds an option <code>showTrailingSpace</code> which, when
enabled, adds the CSS class <code>cm-trailingspace</code> to
stretches of whitespace at the end of lines.
The <a href="../demo/trailingspace.html">demo</a> has a nice
squiggly underline style for this class.</dd>
<dt id="addon_closetag"><a href="../addon/edit/closetag.js"><code>edit/closetag.js</code></a></dt>
<dd>Defines an <code>autoCloseTags</code> option that will
auto-close XML tags when '<code>&gt;</code>' or '<code>/</code>'
is typed, and
a <code>closeTag</code> <a href="#commands">command</a> that
closes the nearest open tag. Depends on
the <code>fold/xml-fold.js</code> addon. See
the <a href="../demo/closetag.html">demo</a>.</dd>
<dt id="addon_continuelist"><a href="../addon/edit/continuelist.js"><code>edit/continuelist.js</code></a></dt>
<dd>Markdown specific. Defines
a <code>"newlineAndIndentContinueMarkdownList"</code> <a href="#commands">command</a>
command that can be bound to <code>enter</code> to automatically
insert the leading characters for continuing a list. See
the <a href="../mode/markdown/index.html">Markdown mode
demo</a>.</dd>
<dt id="addon_comment"><a href="../addon/comment/comment.js"><code>comment/comment.js</code></a></dt>
<dd>Addon for commenting and uncommenting code. Adds three
methods to CodeMirror instances:
<dl>
<dt id="lineComment"><code><strong>lineComment</strong>(from: {line, ch}, to: {line, ch}, ?options: object)</code></dt>
<dd>Set the lines in the given range to be line comments. Will
fall back to <code>blockComment</code> when no line comment
style is defined for the mode.</dd>
<dt id="blockComment"><code><strong>blockComment</strong>(from: {line, ch}, to: {line, ch}, ?options: object)</code></dt>
<dd>Wrap the code in the given range in a block comment. Will
fall back to <code>lineComment</code> when no block comment
style is defined for the mode.</dd>
<dt id="uncomment"><code><strong>uncomment</strong>(from: {line, ch}, to: {line, ch}, ?options: object) → boolean</code></dt>
<dd>Try to uncomment the given range.
Returns <code>true</code> if a comment range was found and
removed, <code>false</code> otherwise.</dd>
</dl>
The <code>options</code> object accepted by these methods may
have the following properties:
<dl>
<dt><code>blockCommentStart, blockCommentEnd, blockCommentLead, lineComment: string</code></dt>
<dd>Override the <a href="#mode_comment">comment string
properties</a> of the mode with custom comment strings.</dd>
<dt><code><strong>padding</strong>: string</code></dt>
<dd>A string that will be inserted after opening and leading
markers, and before closing comment markers. Defaults to a
single space.</dd>
<dt><code><strong>commentBlankLines</strong>: boolean</code></dt>
<dd>Whether, when adding line comments, to also comment lines
that contain only whitespace.</dd>
<dt><code><strong>indent</strong>: boolean</code></dt>
<dd>When adding line comments and this is turned on, it will
align the comment block to the current indentation of the
first line of the block.</dd>
<dt><code><strong>fullLines</strong>: boolean</code></dt>
<dd>When block commenting, this controls whether the whole
lines are indented, or only the precise range that is given.
Defaults to <code>true</code>.</dd>
</dl>
The addon also defines
a <code>toggleComment</code> <a href="#commands">command</a>,
which will try to uncomment the current selection, and if that
fails, line-comments it.</dd>
<dt id="addon_foldcode"><a href="../addon/fold/foldcode.js"><code>fold/foldcode.js</code></a></dt>
<dd>Helps with code folding. Adds a <code>foldCode</code> method
to editor instances, which will try to do a code fold starting
at the given line, or unfold the fold that is already present.
The method takes as first argument the position that should be
folded (may be a line number or
a <a href="#Pos"><code>Pos</code></a>), and as second optional
argument either a range-finder function, or an options object,
supporting the following properties:
<dl>
<dt><code><strong>rangeFinder</strong>: fn(CodeMirror, Pos)</code></dt>
<dd id="helper_fold_auto">The function that is used to find
foldable ranges. If this is not directly passed, it will
default to <code>CodeMirror.fold.auto</code>, which
uses <a href="#getHelpers"><code>getHelpers</code></a> with
a <code>"fold"</code> type to find folding functions
appropriate for the local mode. There are files in
the <a href="../addon/fold/"><code>addon/fold/</code></a>
directory providing <code>CodeMirror.fold.brace</code>, which
finds blocks in brace languages (JavaScript, C, Java,
etc), <code>CodeMirror.fold.indent</code>, for languages where
indentation determines block structure (Python, Haskell),
and <code>CodeMirror.fold.xml</code>, for XML-style languages,
and <code>CodeMirror.fold.comment</code>, for folding comment
blocks.</dd>
<dt><code><strong>widget</strong>: string|Element</code></dt>
<dd>The widget to show for folded ranges. Can be either a
string, in which case it'll become a span with
class <code>CodeMirror-foldmarker</code>, or a DOM node.</dd>
<dt><code><strong>scanUp</strong>: boolean</code></dt>
<dd>When true (default is false), the addon will try to find
foldable ranges on the lines above the current one if there
isn't an eligible one on the given line.</dd>
<dt><code><strong>minFoldSize</strong>: integer</code></dt>
<dd>The minimum amount of lines that a fold should span to be
accepted. Defaults to 0, which also allows single-line
folds.</dd>
</dl>
See <a href="../demo/folding.html">the demo</a> for an
example.</dd>
<dt id="addon_foldgutter"><a href="../addon/fold/foldgutter.js"><code>fold/foldgutter.js</code></a></dt>
<dd>Provides an option <code>foldGutter</code>, which can be
used to create a gutter with markers indicating the blocks that
can be folded. Create a gutter using
the <a href="#option_gutters"><code>gutters</code></a> option,
giving it the class <code>CodeMirror-foldgutter</code> or
something else if you configure the addon to use a different
class, and this addon will show markers next to folded and
foldable blocks, and handle clicks in this gutter. Note that
CSS styles should be applied to make the gutter, and the fold
markers within it, visible. A default set of CSS styles are
available in:
<a href="../addon/fold/foldgutter.css">
<code>addon/fold/foldgutter.css</code>
</a>.
The option
can be either set to <code>true</code>, or an object containing
the following optional option fields:
<dl>
<dt><code><strong>gutter</strong>: string</code></dt>
<dd>The CSS class of the gutter. Defaults
to <code>"CodeMirror-foldgutter"</code>. You will have to
style this yourself to give it a width (and possibly a
background). See the default gutter style rules above.</dd>
<dt><code><strong>indicatorOpen</strong>: string | Element</code></dt>
<dd>A CSS class or DOM element to be used as the marker for
open, foldable blocks. Defaults
to <code>"CodeMirror-foldgutter-open"</code>.</dd>
<dt><code><strong>indicatorFolded</strong>: string | Element</code></dt>
<dd>A CSS class or DOM element to be used as the marker for
folded blocks. Defaults to <code>"CodeMirror-foldgutter-folded"</code>.</dd>
<dt><code><strong>rangeFinder</strong>: fn(CodeMirror, Pos)</code></dt>
<dd>The range-finder function to use when determining whether
something can be folded. When not
given, <a href="#helper_fold_auto"><code>CodeMirror.fold.auto</code></a>
will be used as default.</dd>
</dl>
The <code>foldOptions</code> editor option can be set to an
object to provide an editor-wide default configuration.
Demo <a href="../demo/folding.html">here</a>.</dd>
<dt id="addon_runmode"><a href="../addon/runmode/runmode.js"><code>runmode/runmode.js</code></a></dt>
<dd>Can be used to run a CodeMirror mode over text without
actually opening an editor instance.
See <a href="../demo/runmode.html">the demo</a> for an example.
There are alternate versions of the file avaible for
running <a href="../addon/runmode/runmode-standalone.js">stand-alone</a>
(without including all of CodeMirror) and
for <a href="../addon/runmode/runmode.node.js">running under
node.js</a>.</dd>
<dt id="addon_colorize"><a href="../addon/runmode/colorize.js"><code>runmode/colorize.js</code></a></dt>
<dd>Provides a convenient way to syntax-highlight code snippets
in a webpage. Depends on
the <a href="#addon_runmode"><code>runmode</code></a> addon (or
its standalone variant). Provides
a <code>CodeMirror.colorize</code> function that can be called
with an array (or other array-ish collection) of DOM nodes that
represent the code snippets. By default, it'll get
all <code>pre</code> tags. Will read the <code>data-lang</code>
attribute of these nodes to figure out their language, and
syntax-color their content using the relevant CodeMirror mode
(you'll have to load the scripts for the relevant modes
yourself). A second argument may be provided to give a default
mode, used when no language attribute is found for a node. Used
in this manual to highlight example code.</dd>
<dt id="addon_overlay"><a href="../addon/mode/overlay.js"><code>mode/overlay.js</code></a></dt>
<dd>Mode combinator that can be used to extend a mode with an
'overlay' — a secondary mode is run over the stream, along with
the base mode, and can color specific pieces of text without
interfering with the base mode.
Defines <code>CodeMirror.overlayMode</code>, which is used to
create such a mode. See <a href="../demo/mustache.html">this
demo</a> for a detailed example.</dd>
<dt id="addon_multiplex"><a href="../addon/mode/multiplex.js"><code>mode/multiplex.js</code></a></dt>
<dd>Mode combinator that can be used to easily 'multiplex'
between several modes.
Defines <code>CodeMirror.multiplexingMode</code> which, when
given as first argument a mode object, and as other arguments
any number of <code>{open, close, mode [, delimStyle, innerStyle, parseDelimiters]}</code>
objects, will return a mode object that starts parsing using the
mode passed as first argument, but will switch to another mode
as soon as it encounters a string that occurs in one of
the <code>open</code> fields of the passed objects. When in a
sub-mode, it will go back to the top mode again when
the <code>close</code> string is encountered.
Pass <code>"\n"</code> for <code>open</code> or <code>close</code>
if you want to switch on a blank line.
<ul><li>When <code>delimStyle</code> is specified, it will be the token
style returned for the delimiter tokens.</li>
<li>When <code>innerStyle</code> is specified, it will be the token
style added for each inner mode token.</li>
<li>When <code>parseDelimiters</code> is true, the content of
the delimiters will also be passed to the inner mode.
(And <code>delimStyle</code> is ignored.)</li></ul> The outer
mode will not see the content between the delimiters.
See <a href="../demo/multiplex.html">this demo</a> for an
example.</dd>
<dt id="addon_show-hint"><a href="../addon/hint/show-hint.js"><code>hint/show-hint.js</code></a></dt>
<dd>Provides a framework for showing autocompletion hints.
Defines <code>editor.showHint</code>, which takes an optional
options object, and pops up a widget that allows the user to
select a completion. Finding hints is done with a hinting
functions (the <code>hint</code> option), which is a function
that take an editor instance and options object, and return
a <code>{list, from, to}</code> object, where <code>list</code>
is an array of strings or objects (the completions),
and <code>from</code> and <code>to</code> give the start and end
of the token that is being completed as <code>{line, ch}</code>
objects.</dd>
<dd>If no hinting function is given, the addon will
use <code>CodeMirror.hint.auto</code>, which
calls <a href="#getHelpers"><code>getHelpers</code></a> with
the <code>"hint"</code> type to find applicable hinting
functions, and tries them one by one. If that fails, it looks
for a <code>"hintWords"</code> helper to fetch a list of
completable words for the mode, and
uses <code>CodeMirror.hint.fromList</code> to complete from
those.</dd>
<dd>When completions aren't simple strings, they should be
objects with the following properties:
<dl>
<dt><code><strong>text</strong>: string</code></dt>
<dd>The completion text. This is the only required
property.</dd>
<dt><code><strong>displayText</strong>: string</code></dt>
<dd>The text that should be displayed in the menu.</dd>
<dt><code><strong>className</strong>: string</code></dt>
<dd>A CSS class name to apply to the completion's line in the
menu.</dd>
<dt><code><strong>render</strong>: fn(Element, self, data)</code></dt>
<dd>A method used to create the DOM structure for showing the
completion by appending it to its first argument.</dd>
<dt><code><strong>hint</strong>: fn(CodeMirror, self, data)</code></dt>
<dd>A method used to actually apply the completion, instead of
the default behavior.</dd>
<dt><code><strong>from</strong>: {line, ch}</code></dt>
<dd>Optional <code>from</code> position that will be used by <code>pick()</code> instead
of the global one passed with the full list of completions.</dd>
<dt><code><strong>to</strong>: {line, ch}</code></dt>
<dd>Optional <code>to</code> position that will be used by <code>pick()</code> instead
of the global one passed with the full list of completions.</dd>
</dl>
The plugin understands the following options (the options object
will also be passed along to the hinting function, which may
understand additional options):
<dl>
<dt><code><strong>hint</strong>: function</code></dt>
<dd>A hinting function, as specified above. It is possible to
set the <code>async</code> property on a hinting function to
true, in which case it will be called with
arguments <code>(cm, callback, ?options)</code>, and the
completion interface will only be popped up when the hinting
function calls the callback, passing it the object holding the
completions.</dd>
<dt><code><strong>completeSingle</strong>: boolean</code></dt>
<dd>Determines whether, when only a single completion is
available, it is completed without showing the dialog.
Defaults to true.</dd>
<dt><code><strong>alignWithWord</strong>: boolean</code></dt>
<dd>Whether the pop-up should be horizontally aligned with the
start of the word (true, default), or with the cursor (false).</dd>
<dt><code><strong>closeOnUnfocus</strong>: boolean</code></dt>
<dd>When enabled (which is the default), the pop-up will close
when the editor is unfocused.</dd>
<dt><code><strong>customKeys</strong>: keymap</code></dt>
<dd>Allows you to provide a custom key map of keys to be active
when the pop-up is active. The handlers will be called with an
extra argument, a handle to the completion menu, which
has <code>moveFocus(n)</code>, <code>setFocus(n)</code>, <code>pick()</code>,
and <code>close()</code> methods (see the source for details),
that can be used to change the focused element, pick the
current element or close the menu. Additionnaly <code>menuSize()</code>
can give you access to the size of the current dropdown menu,
<code>length</code> give you the number of availlable completions, and
<code>data</code> give you full access to the completion returned by the
hinting function.</dd>
<dt><code><strong>extraKeys</strong>: keymap</code></dt>
<dd>Like <code>customKeys</code> above, but the bindings will
be added to the set of default bindings, instead of replacing
them.</dd>
</dl>
The following events will be fired on the completions object
during completion:
<dl>
<dt><code><strong>"shown"</strong> ()</code></dt>
<dd>Fired when the pop-up is shown.</dd>
<dt><code><strong>"select"</strong> (completion, Element)</code></dt>
<dd>Fired when a completion is selected. Passed the completion
value (string or object) and the DOM node that represents it
in the menu.</dd>
<dt><code><strong>"pick"</strong> (completion)</code></dt>
<dd>Fired when a completion is picked. Passed the completion value
(string or object).</dd>
<dt><code><strong>"close"</strong> ()</code></dt>
<dd>Fired when the completion is finished.</dd>
</dl>
This addon depends on styles
from <code>addon/hint/show-hint.css</code>. Check
out <a href="../demo/complete.html">the demo</a> for an
example.</dd>
<dt id="addon_javascript-hint"><a href="../addon/hint/javascript-hint.js"><code>hint/javascript-hint.js</code></a></dt>
<dd>Defines a simple hinting function for JavaScript
(<code>CodeMirror.hint.javascript</code>) and CoffeeScript
(<code>CodeMirror.hint.coffeescript</code>) code. This will
simply use the JavaScript environment that the editor runs in as
a source of information about objects and their properties.</dd>
<dt id="addon_xml-hint"><a href="../addon/hint/xml-hint.js"><code>hint/xml-hint.js</code></a></dt>
<dd>Defines <code>CodeMirror.hint.xml</code>, which produces
hints for XML tagnames, attribute names, and attribute values,
guided by a <code>schemaInfo</code> option (a property of the
second argument passed to the hinting function, or the third
argument passed to <code>CodeMirror.showHint</code>).<br>The
schema info should be an object mapping tag names to information
about these tags, with optionally a <code>"!top"</code> property
containing a list of the names of valid top-level tags. The
values of the properties should be objects with optional
properties <code>children</code> (an array of valid child
element names, omit to simply allow all tags to appear)
and <code>attrs</code> (an object mapping attribute names
to <code>null</code> for free-form attributes, and an array of
valid values for restricted
attributes). <a href="../demo/xmlcomplete.html">Demo
here.</a></dd>
<dt id="addon_html-hint"><a href="../addon/hint/html-hint.js"><code>hint/html-hint.js</code></a></dt>
<dd>Provides schema info to
the <a href="#addon_xml-hint">xml-hint</a> addon for HTML
documents. Defines a schema
object <code>CodeMirror.htmlSchema</code> that you can pass to
as a <code>schemaInfo</code> option, and
a <code>CodeMirror.hint.html</code> hinting function that
automatically calls <code>CodeMirror.hint.xml</code> with this
schema data. See
the <a href="../demo/html5complete.html">demo</a>.</dd>
<dt id="addon_css-hint"><a href="../addon/hint/css-hint.js"><code>hint/css-hint.js</code></a></dt>
<dd>A hinting function for CSS, SCSS, or LESS code.
Defines <code>CodeMirror.hint.css</code>.</dd>
<dt id="addon_anyword-hint"><a href="../addon/hint/anyword-hint.js"><code>hint/anyword-hint.js</code></a></dt>
<dd>A very simple hinting function
(<code>CodeMirror.hint.anyword</code>) that simply looks for
words in the nearby code and completes to those. Takes two
optional options, <code>word</code>, a regular expression that
matches words (sequences of one or more character),
and <code>range</code>, which defines how many lines the addon
should scan when completing (defaults to 500).</dd>
<dt id="addon_sql-hint"><a href="../addon/hint/sql-hint.js"><code>hint/sql-hint.js</code></a></dt>
<dd>A simple SQL hinter. Defines <code>CodeMirror.hint.sql</code>.
Takes two optional options, <code>tables</code>, a object with
table names as keys and array of respective column names as values,
and <code>defaultTable</code>, a string corresponding to a
table name in <code>tables</code> for autocompletion.</dd>
<dt id="addon_match-highlighter"><a href="../addon/search/match-highlighter.js"><code>search/match-highlighter.js</code></a></dt>
<dd>Adds a <code>highlightSelectionMatches</code> option that
can be enabled to highlight all instances of a currently
selected word. Can be set either to true or to an object
containing the following options: <code>minChars</code>, for the
minimum amount of selected characters that triggers a highlight
(default 2), <code>style</code>, for the style to be used to
highlight the matches (default <code>"matchhighlight"</code>,
which will correspond to CSS
class <code>cm-matchhighlight</code>),
and <code>showToken</code> which can be set to <code>true</code>
or to a regexp matching the characters that make up a word. When
enabled, it causes the current word to be highlighted when
nothing is selected (defaults to off).
Demo <a href="../demo/matchhighlighter.html">here</a>.</dd>
<dt id="addon_lint"><a href="../addon/lint/lint.js"><code>lint/lint.js</code></a></dt>
<dd>Defines an interface component for showing linting warnings,
with pluggable warning sources
(see <a href="../addon/lint/json-lint.js"><code>json-lint.js</code></a>,
<a href="../addon/lint/javascript-lint.js"><code>javascript-lint.js</code></a>,
<a href="../addon/lint/coffeescript-lint.js"><code>coffeescript-lint.js</code></a>,
and <a href="../addon/lint/css-lint.js"><code>css-lint.js</code></a>
in the same directory). Defines a <code>lint</code> option that
can be set to a warning source (for
example <code>CodeMirror.lint.javascript</code>), or
to <code>true</code>, in which
case <a href="#getHelper"><code>getHelper</code></a> with
type <code>"lint"</code> is used to determined a validator
function. Such a function should, when given a document string,
an options object, and an editor instance, return an array of <code>{message,
severity, from, to}</code> objects representing problems. When
the function has an <code>async</code> property with a truthy
value, it will be called with an additional second argument,
which is a callback to pass the array to. Depends
on <code>addon/lint/lint.css</code>. A demo can be
found <a href="../demo/lint.html">here</a>.</dd>
<dt id="addon_mark-selection"><a href="../addon/selection/mark-selection.js"><code>selection/mark-selection.js</code></a></dt>
<dd>Causes the selected text to be marked with the CSS class
<code>CodeMirror-selectedtext</code> when the <code>styleSelectedText</code> option
is enabled. Useful to change the colour of the selection (in addition to the background),
like in <a href="../demo/markselection.html">this demo</a>.</dd>
<dt id="addon_active-line"><a href="../addon/selection/active-line.js"><code>selection/active-line.js</code></a></dt>
<dd>Defines a <code>styleActiveLine</code> option that, when enabled,
gives the wrapper of the active line the class <code>CodeMirror-activeline</code>,
and adds a background with the class <code>CodeMirror-activeline-background</code>.
is enabled. See the <a href="../demo/activeline.html">demo</a>.</dd>
<dt id="addon_selection-pointer"><a href="../addon/selection/selection-pointer.js"><code>selection/selection-pointer.js</code></a></dt>
<dd>Defines a <code>selectionPointer</code> option which you can
use to control the mouse cursor appearance when hovering over
the selection. It can be set to a string,
like <code>"pointer"</code>, or to true, in which case
the <code>"default"</code> (arrow) cursor will be used. You can
see a demo <a href="../mode/htmlmixed/index.html">here</a>.</dd>
<dt id="addon_loadmode"><a href="../addon/mode/loadmode.js"><code>mode/loadmode.js</code></a></dt>
<dd>Defines a <code>CodeMirror.requireMode(modename,
callback)</code> function that will try to load a given mode and
call the callback when it succeeded. You'll have to
set <code>CodeMirror.modeURL</code> to a string that mode paths
can be constructed from, for
example <code>"mode/%N/%N.js"</code>—the <code>%N</code>'s will
be replaced with the mode name. Also
defines <code>CodeMirror.autoLoadMode(instance, mode)</code>,
which will ensure the given mode is loaded and cause the given
editor instance to refresh its mode when the loading
succeeded. See the <a href="../demo/loadmode.html">demo</a>.</dd>
<dt id="addon_meta"><a href="../mode/meta.js"><code>mode/meta.js</code></a></dt>
<dd>Provides meta-information about all the modes in the
distribution in a single file.
Defines <code>CodeMirror.modeInfo</code>, an array of objects
with <code>{name, mime, mode}</code> properties,
where <code>name</code> is the human-readable
name, <code>mime</code> the MIME type, and <code>mode</code> the
name of the mode file that defines this MIME. There are optional
properties <code>mimes</code>, which holds an array of MIME
types for modes with multiple MIMEs associated,
and <code>ext</code>, which holds an array of file extensions
associated with this mode. Four convenience
functions, <code>CodeMirror.findModeByMIME</code>,
<code>CodeMirror.findModeByExtension</code>,
<code>CodeMirror.findModeByFileName</code>
and <code>CodeMirror.findModeByName</code> are provided, which
return such an object given a MIME, extension, file name or mode name
string. Note that, for historical reasons, this file resides in the
top-level <code>mode</code> directory, not
under <code>addon</code>. <a href="../demo/loadmode.html">Demo</a>.</dd>
<dt id="addon_continuecomment"><a href="../addon/comment/continuecomment.js"><code>comment/continuecomment.js</code></a></dt>
<dd>Adds a <code>continueComments</code> option, which sets whether the
editor will make the next line continue a comment when you press Enter
inside a comment block. Can be set to a boolean to enable/disable this
functionality. Set to a string, it will continue comments using a custom
shortcut. Set to an object, it will use the <code>key</code> property for
a custom shortcut and the boolean <code>continueLineComment</code>
property to determine whether single-line comments should be continued
(defaulting to <code>true</code>).</dd>
<dt id="addon_placeholder"><a href="../addon/display/placeholder.js"><code>display/placeholder.js</code></a></dt>
<dd>Adds a <code>placeholder</code> option that can be used to
make text appear in the editor when it is empty and not focused.
Also gives the editor a <code>CodeMirror-empty</code> CSS class
whenever it doesn't contain any text.
See <a href="../demo/placeholder.html">the demo</a>.</dd>
<dt id="addon_fullscreen"><a href="../addon/display/fullscreen.js"><code>display/fullscreen.js</code></a></dt>
<dd>Defines an option <code>fullScreen</code> that, when set
to <code>true</code>, will make the editor full-screen (as in,
taking up the whole browser window). Depends
on <a href="../addon/display/fullscreen.css"><code>fullscreen.css</code></a>. <a href="../demo/fullscreen.html">Demo
here</a>.</dd>
<dt id="addon_simplescrollbars"><a href="../addon/scroll/simplescrollbars.js"><code>scroll/simplescrollbars.js</code></a></dt>
<dd>Defines two additional scrollbar
models, <code>"simple"</code> and <code>"overlay"</code>
(see <a href="../demo/simplescrollbars.html">demo</a>) that can
be selected with
the <a href="#option_scrollbarStyle"><code>scrollbarStyle</code></a>
option. Depends
on <a href="../addon/scroll/simplescrollbars.css"><code>simplescrollbars.css</code></a>,
which can be further overridden to style your own
scrollbars.</dd>
<dt id="addon_annotatescrollbar"><a href="../addon/scroll/annotatescrollbar.js"><code>scroll/annotatescrollbar.js</code></a></dt>
<dd>Provides functionality for showing markers on the scrollbar
to call out certain parts of the document. Adds a
method <code>annotateScrollbar</code> to editor instances that
can be called, with a CSS class name as argument, to create a
set of annotations. The method returns an object
whose <code>update</code> method can be called with an array
of <code>{from: Pos, to: Pos}</code> objects marking the ranges
to be higlighed. To detach the annotations, call the
object's <code>clear</code> method.</dd>
<dt id="addon_rulers"><a href="../addon/display/rulers.js"><code>display/rulers.js</code></a></dt>
<dd>Adds a <code>rulers</code> option, which can be used to show
one or more vertical rulers in the editor. The option, if
defined, should be given an array of <code>{column [, className,
color, lineStyle, width]}</code> objects or numbers (wich
indicate a column). The ruler will be displayed at the column
indicated by the number or the <code>column</code> property.
The <code>className</code> property can be used to assign a
custom style to a ruler. <a href="../demo/rulers.html">Demo
here</a>.</dd>
<dt id="addon_panel"><a href="../addon/display/panel.js"><code>display/panel.js</code></a></dt>
<dd>Defines an <code>addPanel</code> method for CodeMirror
instances, which places a DOM node above or below an editor, and
shrinks the editor to make room for the node. The method takes
as first argument as DOM node, and as second an optional options
object. The <code>Panel</code> object returned by this method
has a <code>clear</code> method that is used to remove the
panel, and a <code>changed</code> method that can be used to
notify the addon when the size of the panel's DOM node has
changed.<br/>
The method accepts the following options:
<dl>
<dt><code><strong>position</strong> : string</code></dt>
<dd>Controls the position of the newly added panel. The
following values are recognized:
<dl>
<dt><code><strong>top</strong> (default)</code></dt>
<dd>Adds the panel at the very top.</dd>
<dt><code><strong>after-top</strong></code></dt>
<dd>Adds the panel at the bottom of the top panels.</dd>
<dt><code><strong>bottom</strong></code></dt>
<dd>Adds the panel at the very bottom.</dd>
<dt><code><strong>before-bottom</strong></code></dt>
<dd>Adds the panel at the top of the bottom panels.</dd>
</dl>
</dd>
<dt><code><strong>before</strong> : Panel</code></dt>
<dd>The new panel will be added before the given panel.</dd>
<dt><code><strong>after</strong> : Panel</code></dt>
<dd>The new panel will be added after the given panel.</dd>
<dt><code><strong>replace</strong> : Panel</code></dt>
<dd>The new panel will replace the given panel.</dd>
</dl>
When using the <code>after</code>, <code>before</code> or <code>replace</code> options,
if the panel doesn't exists or has been removed,
the value of the <code>position</code> option will be used as a fallback.
<br>
A demo of the addon is available <a href="../demo/panel.html">here</a>.
</dd>
<dt id="addon_hardwrap"><a href="../addon/wrap/hardwrap.js"><code>wrap/hardwrap.js</code></a></dt>
<dd>Addon to perform hard line wrapping/breaking for paragraphs
of text. Adds these methods to editor instances:
<dl>
<dt><code><strong>wrapParagraph</strong>(?pos: {line, ch}, ?options: object)</code></dt>
<dd>Wraps the paragraph at the given position.
If <code>pos</code> is not given, it defaults to the cursor
position.</dd>
<dt><code><strong>wrapRange</strong>(from: {line, ch}, to: {line, ch}, ?options: object)</code></dt>
<dd>Wraps the given range as one big paragraph.</dd>
<dt><code><strong>wrapParagraphsInRange</strong>(from: {line, ch}, to: {line, ch}, ?options: object)</code></dt>
<dd>Wrapps the paragraphs in (and overlapping with) the
given range individually.</dd>
</dl>
The following options are recognized:
<dl>
<dt><code><strong>paragraphStart</strong>, <strong>paragraphEnd</strong>: RegExp</code></dt>
<dd>Blank lines are always considered paragraph boundaries.
These options can be used to specify a pattern that causes
lines to be considered the start or end of a paragraph.</dd>
<dt><code><strong>column</strong>: number</code></dt>
<dd>The column to wrap at. Defaults to 80.</dd>
<dt><code><strong>wrapOn</strong>: RegExp</code></dt>
<dd>A regular expression that matches only those
two-character strings that allow wrapping. By default, the
addon wraps on whitespace and after dash characters.</dd>
<dt><code><strong>killTrailingSpace</strong>: boolean</code></dt>
<dd>Whether trailing space caused by wrapping should be
preserved, or deleted. Defaults to true.</dd>
</dl>
A demo of the addon is available <a href="../demo/hardwrap.html">here</a>.
</dd>
<dt id="addon_merge"><a href="../addon/merge/merge.js"><code>merge/merge.js</code></a></dt>
<dd>Implements an interface for merging changes, using either a
2-way or a 3-way view. The <code>CodeMirror.MergeView</code>
constructor takes arguments similar to
the <a href="#CodeMirror"><code>CodeMirror</code></a>
constructor, first a node to append the interface to, and then
an options object. Options are passed through to the editors
inside the view. These extra options are recognized:
<dl>
<dt><code><strong>origLeft</strong></code> and <code><strong>origRight</strong>: string</code></dt>
<dd>If given these provide original versions of the
document, which will be shown to the left and right of the
editor in non-editable CodeMirror instances. The merge
interface will highlight changes between the editable
document and the original(s). To create a 2-way (as opposed
to 3-way) merge view, provide only one of them.</dd>
<dt><code><strong>revertButtons</strong>: boolean</code></dt>
<dd>Determines whether buttons that allow the user to revert
changes are shown. Defaults to true.</dd>
<dt><code><strong>connect</strong>: string</code></dt>
<dd>Sets the style used to connect changed chunks of code.
By default, connectors are drawn. When this is set
to <code>"align"</code>, the smaller chunk is padded to
align with the bigger chunk instead.</dd>
<dt><code><strong>collapseIdentical</strong>: boolean|number</code></dt>
<dd>When true (default is false), stretches of unchanged
text will be collapsed. When a number is given, this
indicates the amount of lines to leave visible around such
stretches (which defaults to 2).</dd>
<dt><code><strong>allowEditingOriginals</strong>: boolean</code></dt>
<dd>Determines whether the original editor allows editing.
Defaults to false.</dd>
<dt><code><strong>showDifferences</strong>: boolean</code></dt>
<dd>When true (the default), changed pieces of text are
highlighted.</dd>
</dl>
The addon also defines commands <code>"goNextDiff"</code>
and <code>"goPrevDiff"</code> to quickly jump to the next
changed chunk. <a href="../demo/merge.html">Demo
here</a>.</dd>
<dt id="addon_tern"><a href="../addon/tern/tern.js"><code>tern/tern.js</code></a></dt>
<dd>Provides integration with
the <a href="http://ternjs.net">Tern</a> JavaScript analysis
engine, for completion, definition finding, and minor
refactoring help. See the <a href="../demo/tern.html">demo</a>
for a very simple integration. For more involved scenarios, see
the comments at the top of
the <a href="../addon/tern/tern.js">addon</a> and the
implementation of the
(multi-file) <a href="http://ternjs.net/doc/demo.html">demonstration
on the Tern website</a>.</dd>
</dl>
</section>
<section id=modeapi>
<h2>Writing CodeMirror Modes</h2>
<p>Modes typically consist of a single JavaScript file. This file
defines, in the simplest case, a lexer (tokenizer) for your
language—a function that takes a character stream as input,
advances it past a token, and returns a style for that token. More
advanced modes can also handle indentation for the language.</p>
<p>This section describes the low-level mode interface. Many modes
are written directly against this, since it offers a lot of
control, but for a quick mode definition, you might want to use
the <a href="../demo/simplemode.html">simple mode addon</a>.</p>
<p id="defineMode">The mode script should
call <code><strong>CodeMirror.defineMode</strong></code> to
register itself with CodeMirror. This function takes two
arguments. The first should be the name of the mode, for which you
should use a lowercase string, preferably one that is also the
name of the files that define the mode (i.e. <code>"xml"</code> is
defined in <code>xml.js</code>). The second argument should be a
function that, given a CodeMirror configuration object (the thing
passed to the <code>CodeMirror</code> function) and an optional
mode configuration object (as in
the <a href="#option_mode"><code>mode</code></a> option), returns
a mode object.</p>
<p>Typically, you should use this second argument
to <code>defineMode</code> as your module scope function (modes
should not leak anything into the global scope!), i.e. write your
whole mode inside this function.</p>
<p>The main responsibility of a mode script is <em>parsing</em>
the content of the editor. Depending on the language and the
amount of functionality desired, this can be done in really easy
or extremely complicated ways. Some parsers can be stateless,
meaning that they look at one element (<em>token</em>) of the code
at a time, with no memory of what came before. Most, however, will
need to remember something. This is done by using a <em>state
object</em>, which is an object that is always passed when
reading a token, and which can be mutated by the tokenizer.</p>
<p id="startState">Modes that use a state must define
a <code><strong>startState</strong></code> method on their mode
object. This is a function of no arguments that produces a state
object to be used at the start of a document.</p>
<p id="token">The most important part of a mode object is
its <code><strong>token</strong>(stream, state)</code> method. All
modes must define this method. It should read one token from the
stream it is given as an argument, optionally update its state,
and return a style string, or <code>null</code> for tokens that do
not have to be styled. For your styles, you are encouraged to use
the 'standard' names defined in the themes (without
the <code>cm-</code> prefix). If that fails, it is also possible
to come up with your own and write your own CSS theme file.<p>
<p id="token_style_line">A typical token string would
be <code>"variable"</code> or <code>"comment"</code>. Multiple
styles can be returned (separated by spaces), for
example <code>"string error"</code> for a thing that looks like a
string but is invalid somehow (say, missing its closing quote).
When a style is prefixed by <code>"line-"</code>
or <code>"line-background-"</code>, the style will be applied to
the whole line, analogous to what
the <a href="#addLineClass"><code>addLineClass</code></a> method
does—styling the <code>"text"</code> in the simple case, and
the <code>"background"</code> element
when <code>"line-background-"</code> is prefixed.</p>
<p id="StringStream">The stream object that's passed
to <code>token</code> encapsulates a line of code (tokens may
never span lines) and our current position in that line. It has
the following API:</p>
<dl>
<dt><code><strong>eol</strong>() → boolean</code></dt>
<dd>Returns true only if the stream is at the end of the
line.</dd>
<dt><code><strong>sol</strong>() → boolean</code></dt>
<dd>Returns true only if the stream is at the start of the
line.</dd>
<dt><code><strong>peek</strong>() → string</code></dt>
<dd>Returns the next character in the stream without advancing
it. Will return an <code>null</code> at the end of the
line.</dd>
<dt><code><strong>next</strong>() → string</code></dt>
<dd>Returns the next character in the stream and advances it.
Also returns <code>null</code> when no more characters are
available.</dd>
<dt><code><strong>eat</strong>(match: string|regexp|function(char: string) → boolean) → string</code></dt>
<dd><code>match</code> can be a character, a regular expression,
or a function that takes a character and returns a boolean. If
the next character in the stream 'matches' the given argument,
it is consumed and returned. Otherwise, <code>undefined</code>
is returned.</dd>
<dt><code><strong>eatWhile</strong>(match: string|regexp|function(char: string) → boolean) → boolean</code></dt>
<dd>Repeatedly calls <code>eat</code> with the given argument,
until it fails. Returns true if any characters were eaten.</dd>
<dt><code><strong>eatSpace</strong>() → boolean</code></dt>
<dd>Shortcut for <code>eatWhile</code> when matching
white-space.</dd>
<dt><code><strong>skipToEnd</strong>()</code></dt>
<dd>Moves the position to the end of the line.</dd>
<dt><code><strong>skipTo</strong>(ch: string) → boolean</code></dt>
<dd>Skips to the next occurrence of the given character, if
found on the current line (doesn't advance the stream if the
character does not occur on the line). Returns true if the
character was found.</dd>
<dt><code><strong>match</strong>(pattern: string, ?consume: boolean, ?caseFold: boolean) → boolean</code></dt>
<dt><code><strong>match</strong>(pattern: regexp, ?consume: boolean) → array&lt;string&gt;</code></dt>
<dd>Act like a
multi-character <code>eat</code>—if <code>consume</code> is true
or not given—or a look-ahead that doesn't update the stream
position—if it is false. <code>pattern</code> can be either a
string or a regular expression starting with <code>^</code>.
When it is a string, <code>caseFold</code> can be set to true to
make the match case-insensitive. When successfully matching a
regular expression, the returned value will be the array
returned by <code>match</code>, in case you need to extract
matched groups.</dd>
<dt><code><strong>backUp</strong>(n: integer)</code></dt>
<dd>Backs up the stream <code>n</code> characters. Backing it up
further than the start of the current token will cause things to
break, so be careful.</dd>
<dt><code><strong>column</strong>() → integer</code></dt>
<dd>Returns the column (taking into account tabs) at which the
current token starts.</dd>
<dt><code><strong>indentation</strong>() → integer</code></dt>
<dd>Tells you how far the current line has been indented, in
spaces. Corrects for tab characters.</dd>
<dt><code><strong>current</strong>() → string</code></dt>
<dd>Get the string between the start of the current token and
the current stream position.</dd>
</dl>
<p id="blankLine">By default, blank lines are simply skipped when
tokenizing a document. For languages that have significant blank
lines, you can define
a <code><strong>blankLine</strong>(state)</code> method on your
mode that will get called whenever a blank line is passed over, so
that it can update the parser state.</p>
<p id="copyState">Because state object are mutated, and CodeMirror
needs to keep valid versions of a state around so that it can
restart a parse at any line, copies must be made of state objects.
The default algorithm used is that a new state object is created,
which gets all the properties of the old object. Any properties
which hold arrays get a copy of these arrays (since arrays tend to
be used as mutable stacks). When this is not correct, for example
because a mode mutates non-array properties of its state object, a
mode object should define
a <code><strong>copyState</strong></code> method, which is given a
state and should return a safe copy of that state.</p>
<p id="indent">If you want your mode to provide smart indentation
(through the <a href="#indentLine"><code>indentLine</code></a>
method and the <code>indentAuto</code>
and <code>newlineAndIndent</code> commands, to which keys can be
<a href="#option_extraKeys">bound</a>), you must define
an <code><strong>indent</strong>(state, textAfter)</code> method
on your mode object.</p>
<p>The indentation method should inspect the given state object,
and optionally the <code>textAfter</code> string, which contains
the text on the line that is being indented, and return an
integer, the amount of spaces to indent. It should usually take
the <a href="#option_indentUnit"><code>indentUnit</code></a>
option into account. An indentation method may
return <code>CodeMirror.Pass</code> to indicate that it
could not come up with a precise indentation.</p>
<p id="mode_comment">To work well with
the <a href="#addon_comment">commenting addon</a>, a mode may
define <code><strong>lineComment</strong></code> (string that
starts a line
comment), <code><strong>blockCommentStart</strong></code>, <code><strong>blockCommentEnd</strong></code>
(strings that start and end block comments),
and <code>blockCommentLead</code> (a string to put at the start of
continued lines in a block comment). All of these are
optional.</p>
<p id="electricChars">Finally, a mode may define either
an <code>electricChars</code> or an <code>electricInput</code>
property, which are used to automatically reindent the line when
certain patterns are typed and
the <a href="#option_electricChars"><code>electricChars</code></a>
option is enabled. <code>electricChars</code> may be a string, and
will trigger a reindent whenever one of the characters in that
string are typed. Often, it is more appropriate to
use <code>electricInput</code>, which should hold a regular
expression, and will trigger indentation when the part of the
line <em>before</em> the cursor matches the expression. It should
usually end with a <code>$</code> character, so that it only
matches when the indentation-changing pattern was just typed, not when something was
typed after the pattern.</p>
<p>So, to summarize, a mode <em>must</em> provide
a <code>token</code> method, and it <em>may</em>
provide <code>startState</code>, <code>copyState</code>,
and <code>indent</code> methods. For an example of a trivial mode,
see the <a href="../mode/diff/diff.js">diff mode</a>, for a more
involved example, see the <a href="../mode/clike/clike.js">C-like
mode</a>.</p>
<p>Sometimes, it is useful for modes to <em>nest</em>—to have one
mode delegate work to another mode. An example of this kind of
mode is the <a href="../mode/htmlmixed/htmlmixed.js">mixed-mode HTML
mode</a>. To implement such nesting, it is usually necessary to
create mode objects and copy states yourself. To create a mode
object, there are <code>CodeMirror.getMode(options,
parserConfig)</code>, where the first argument is a configuration
object as passed to the mode constructor function, and the second
argument is a mode specification as in
the <a href="#option_mode"><code>mode</code></a> option. To copy a
state object, call <code>CodeMirror.copyState(mode, state)</code>,
where <code>mode</code> is the mode that created the given
state.</p>
<p id="innerMode">In a nested mode, it is recommended to add an
extra method, <code><strong>innerMode</strong></code> which, given
a state object, returns a <code>{state, mode}</code> object with
the inner mode and its state for the current position. These are
used by utility scripts such as the <a href="#addon_closetag">tag
closer</a> to get context information. Use
the <code>CodeMirror.innerMode</code> helper function to, starting
from a mode and a state, recursively walk down to the innermost
mode and state.</p>
<p>To make indentation work properly in a nested parser, it is
advisable to give the <code>startState</code> method of modes that
are intended to be nested an optional argument that provides the
base indentation for the block of code. The JavaScript and CSS
parser do this, for example, to allow JavaScript and CSS code
inside the mixed-mode HTML mode to be properly indented.</p>
<p id="defineMIME">It is possible, and encouraged, to associate
your mode, or a certain configuration of your mode, with
a <a href="http://en.wikipedia.org/wiki/MIME">MIME</a> type. For
example, the JavaScript mode associates itself
with <code>text/javascript</code>, and its JSON variant
with <code>application/json</code>. To do this,
call <code><strong>CodeMirror.defineMIME</strong>(mime,
modeSpec)</code>, where <code>modeSpec</code> can be a string or
object specifying a mode, as in
the <a href="#option_mode"><code>mode</code></a> option.</p>
<p>If a mode specification wants to add some properties to the
resulting mode object, typically for use
with <a href="#getHelpers"><code>getHelpers</code></a>, it may
contain a <code>modeProps</code> property, which holds an object.
This object's properties will be copied to the actual mode