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A standalone JavaScript library for rendering code/class diagrams on your web page. View Examples

Pinker gives the user control over the layout of the diagram, so you can render more complicated diagrams.

Supports: UML diagrams, nested scopes, arrows crossing scopes, and aliases.

Since Pinker has a plain-text format, it is version-control-friendly.

Using Pinker in a Web Page


Specify exactly when and how Pinker diagrams should be drawn. Demo

		<script src='Pinker.js'></script>
		<pre id='Source01'>
		<canvas id='Canvas01'></canvas>
			var canvas = document.getElementById("Canvas01");
			var source = document.getElementById("Source01").innerHTML;
			pinker.draw(canvas, source);


Every <pre class='pinker'> element will be rendered as a Pinker diagram. The diagram source will be replaced with the resulting <canvas> element. Demo

		<script src='Pinker.js'></script>
		<pre id='Source01' class='pinker'>
<script type='text/javascript'>

Pinker Syntax

Indentation is not important; you can use indentation to make the source more legible.

End-lines are important.

Pinker will render as much of a diagram as it can make sense of. If parts of the source conflict with each other, Pinker will render the first/earlier part of the source.


The source is the text/string that describes your diagram.

Most of the examples below are of sources.


A scope is an enclosing rectangle/shape around zero or more scopes. Scopes cannot partially overlap.

Scopes are delimited by square brackets [].

The simplest scope just contains a label. Labels can be made of any characters except square brackets and end-lines.

[Scope Label]

Arrow Types

Plain arrow, for associations: ->

Hollow arrow, for inheritance: -D or -:> (upper case letter D)

Hollow diamond, for aggregation: -o (lower case letter O)

Filled diamond, for composition: -+

Quantity 1: -1

Quantity Mandatory 1: -11

Quantity Many: -N

Quantity 0 or 1: -01

Quantity 1 to Many: -1N

Quantity 0 to Many: -0N

Arrows can point right or left, and can be double-headed, such as <:->.

Line Types

Solid line: ->

Dashed line: => or -->

Dotted line: *>

Any kind of line can be combined with any kind of arrow. Leave off the arrow-head for a plain line.

Single-Level Diagram

In a single-level diagram, all scopes are at the same level of detail.

The source is made up of a Layout section and a Relate section. Each section header ends with a colon and an end-line.


The Layout section defines the basic visual relationship of the scopes.

All layouts are divided into horizontal rows. In this example, row 1 is made up of scopes [A], [B], and [C] laid out left to right. Row 2 is made up of scope [D] aligned to the left and scope [E] aligned to the right. The ellipses ... indicate the alignment change from left (the default) to right.

The Relate section defines connections between scopes. Each line in this section starts with 1 scope and an arrow type, followed by a comma-delimited list of other scopes. An arrow will be drawn from the starting scope to each of the other scopes.

The Relate section is optional.

Multi-Level Diagram

In a multi-level diagram, scopes can be nested inside scopes. You can create any level of nesting.

To nest a diagram within a scope, create a section with the same label as the enclosing scope.

To reference a nested scope, specify the entire path to the scope using period-delimiters. For example, [D] is nested inside [A] so it is referenced as [A.D].


Relations can be made across scopes. For example, [C] has a relation to [A.D.G]. Since [C] and [D] exist in the same scope, the relative reference [D.G] is sufficient. Relative references will be checked before global references.

Labels on Lines

A line between two scopes can be labeled at the start, in the middle, and/or at the end.

Labels are defined on the same source row as the relationship, after a whitespace. Labels are surrounded by double-quotes and are separated by colons.

	[A1]->[A2] "middle label"
	[B1]->[B2] :"middle label":
	[C1]->[C2] "start label":"middle label":"end label"
	[D1]->[D2] "start label"::"end label"
	[E1]->[E2] "start label":"end label"
	[F1]->[F2] "start label":
	[G1]->[G2] :"end label"

An arrow that points to the left, such as [A]<-[B], still "starts" at [A] and "ends" at [B].


Since some labels can be very long, Pinker supports aliases.

Aliases are labels surrounded by curly braces {}. They are defined at the very beginning of a scope label. An alias can include any characters except curly braces, square braces, and end-lines.

When referencing an aliased scope in either a section header or a relation, write {A} instead of [A].

Aliases are all global and must be unique to a diagram. When you use an alias in a relation, you never include the full path to the alias. For example, [D]->{C} instead of [D]->[A].{C}.

	[{A}Some Very Long Label][{B}Another Very Long Label]
		[{C}More Long Labels]

A relative reference may start from any alias. The syntax is {A}.[B.C] where {A} is the global alias and [B.C] is the rest of the path from that point, with scope [C] nested in scope [B].


To include more than a label in a scope, add a Define section. This section is optional.

A definition can contain any number of lines of text. This text will be displayed as-is, with no line-wrapping. Empty lines, leading space, and trailing space will be ignored.

The pipe | character inserts a horizontal rule between lines of text. It can appear at the end of the previous line, the beginning of the next line, or on its own line.

		+ field01
		+ field02
		|+ method01
		- method02
		+ field01


Changing individual configuration settings: pinker.config.attribute = value;

Passing multiple configuration settings:
pinker.draw(canvasElement, sourceText, options);

Attribute Data Type Description
fontSize integer or float font size in pixels
fontFamily string font family
scopeMargin integer or float minimum space around each scope
scopePadding integer or float minimum space between scope boundary and nested scopes
labelPadding integer or float minimum space between scope boundary and text areas
canvasPadding integer or float minimum space between canvas boundary and scopes
backgroundColor string, like "#FFFFFF" diagram background color
shadeColor string, like "#FFFFFF" accent color
lineColor string, like "#000000" line and text color
lineWeight integer or float line weight of lowest-level scopes in pixels
lineDashLength integer or float length of a dash in pixels
lineDashSpacing integer or float length of space between dashes in pixels
arrowHeadArea integer or float pixels-squared area of an arrow head
estimateFontHeight function() returns height of font in pixels
lineSpacing function() returns padding distance between lines of text in pixels
favorGoldenRatioLabelSize boolean should multi-line labels be arranged with a width:height ratio close to 1.6?
favorUniformNodeSizes boolean should sibling-nodes be resized to appear similar?
useSmartArrows boolean instead of drawing straight lines between scopes, draw arrows to route around scopes
keepSource boolean on render(), add the diagram next to the source instead of overwriting the source


MIT License


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Version Notes

Uses Semantic Versioning 2.0.0.

To see what version you are using: let v = pinker.version;

In Progress - v1.4.0

  • bug fix #7: dividing line (from Define section) sometimes not centered in node
  • bug fix #6: trailing whitespace in source cause parsing errors
  • bug fix #4: Relate fails to find local address under non-first-level alias
  • bug fix: removed CORS render option which is no longer supported in FireFox

Labels and Relations - v1.3.0

  • support labels on relationship lines/arrows
  • support passing multiple options into render() and draw()
  • support arrows pointing right or left; support double-headed arrows
  • support lists on both sides of a Relate line
  • support dotted lines
  • support quantitative arrows
  • bug fix: parsing Relate row when label contains a comma
  • refactoring
  • test cases

Smart Arrows - v1.2.0

  • support for curl, elbow, and zigzag SmartArrows
  • spread out coincident paths (vertical, horizontal) with or without SmartArrows
  • additional option for .render() and .draw(): do not overwrite the source
  • config option: "useSmartArrows" turns SmartArrows on/off
  • config option: "labelPadding" for padding around text blocks
  • bug fix: finding scopes by relative paths
  • bug fix: finding scopes by aliased paths
  • bug fix: aliased scopes

Improved Layout - v1.1.0

  • favor horizontal/vertical lines over angled lines
  • favor golden-ratio labels
  • favor more homogeneous scope sizes
  • update plain arrow head for visibility
  • update arrow head sizes to be more regular
  • clean up define-section layout
  • center sub-diagrams in each scope
  • move more layout control into pinker.config
  • refactoring

Initial Release - v1.0.0

  • single-file JavaScript library with no dependencies
  • generate code/UML diagrams from plain text
  • supports nested scopes to any level
  • supports arrows across scopes
  • supports aliases


A standalone JavaScript library for rendering code dependency diagrams on your web page.




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