Render and control web pages.
Process: Main
webContents
is an EventEmitter.
It is responsible for rendering and controlling a web page and is a property of
the BrowserWindow
object. An example of accessing the
webContents
object:
const { BrowserWindow } = require('electron')
const win = new BrowserWindow({ width: 800, height: 1500 })
win.loadURL('http://github.com')
const contents = win.webContents
console.log(contents)
These methods can be accessed from the webContents
module:
const { webContents } = require('electron')
console.log(webContents)
Returns WebContents[]
- An array of all WebContents
instances. This will contain web contents
for all windows, webviews, opened devtools, and devtools extension background pages.
Returns WebContents
- The web contents that is focused in this application, otherwise
returns null
.
id
Integer
Returns WebContents
| undefined - A WebContents instance with the given ID, or
undefined
if there is no WebContents associated with the given ID.
Render and control the contents of a BrowserWindow instance.
Process: Main
Emitted when the navigation is done, i.e. the spinner of the tab has stopped
spinning, and the onload
event was dispatched.
Returns:
event
EventerrorCode
IntegererrorDescription
StringvalidatedURL
StringisMainFrame
BooleanframeProcessId
IntegerframeRoutingId
Integer
This event is like did-finish-load
but emitted when the load failed.
The full list of error codes and their meaning is available here.
Returns:
event
EventerrorCode
IntegererrorDescription
StringvalidatedURL
StringisMainFrame
BooleanframeProcessId
IntegerframeRoutingId
Integer
This event is like did-fail-load
but emitted when the load was cancelled
(e.g. window.stop()
was invoked).
Returns:
event
EventisMainFrame
BooleanframeProcessId
IntegerframeRoutingId
Integer
Emitted when a frame has done navigation.
Corresponds to the points in time when the spinner of the tab started spinning.
Corresponds to the points in time when the spinner of the tab stopped spinning.
Returns:
event
Event
Emitted when the document in the given frame is loaded.
Returns:
event
Eventtitle
StringexplicitSet
Boolean
Fired when page title is set during navigation. explicitSet
is false when
title is synthesized from file url.
Returns:
event
Eventfavicons
String[] - Array of URLs.
Emitted when page receives favicon urls.
Returns:
event
NewWindowWebContentsEventurl
StringframeName
Stringdisposition
String - Can bedefault
,foreground-tab
,background-tab
,new-window
,save-to-disk
andother
.options
BrowserWindowConstructorOptions - The options which will be used for creating the newBrowserWindow
.additionalFeatures
String[] - The non-standard features (features not handled by Chromium or Electron) given towindow.open()
.referrer
Referrer - The referrer that will be passed to the new window. May or may not result in theReferer
header being sent, depending on the referrer policy.postBody
PostBody (optional) - The post data that will be sent to the new window, along with the appropriate headers that will be set. If no post data is to be sent, the value will benull
. Only defined when the window is being created by a form that settarget=_blank
.
Emitted when the page requests to open a new window for a url
. It could be
requested by window.open
or an external link like <a target='_blank'>
.
By default a new BrowserWindow
will be created for the url
.
Calling event.preventDefault()
will prevent Electron from automatically creating a
new BrowserWindow
. If you call event.preventDefault()
and manually create a new
BrowserWindow
then you must set event.newGuest
to reference the new BrowserWindow
instance, failing to do so may result in unexpected behavior. For example:
myBrowserWindow.webContents.on('new-window', (event, url, frameName, disposition, options, additionalFeatures, referrer, postBody) => {
event.preventDefault()
const win = new BrowserWindow({
webContents: options.webContents, // use existing webContents if provided
show: false
})
win.once('ready-to-show', () => win.show())
if (!options.webContents) {
const loadOptions = {
httpReferrer: referrer
}
if (postBody != null) {
const { data, contentType, boundary } = postBody
loadOptions.postData = postBody.data
loadOptions.extraHeaders = `content-type: ${contentType}; boundary=${boundary}`
}
win.loadURL(url, loadOptions) // existing webContents will be navigated automatically
}
event.newGuest = win
})
Returns:
event
Eventurl
String
Emitted when a user or the page wants to start navigation. It can happen when
the window.location
object is changed or a user clicks a link in the page.
This event will not emit when the navigation is started programmatically with
APIs like webContents.loadURL
and webContents.back
.
It is also not emitted for in-page navigations, such as clicking anchor links
or updating the window.location.hash
. Use did-navigate-in-page
event for
this purpose.
Calling event.preventDefault()
will prevent the navigation.
Returns:
event
Eventurl
StringisInPlace
BooleanisMainFrame
BooleanframeProcessId
IntegerframeRoutingId
Integer
Emitted when any frame (including main) starts navigating. isInplace
will be
true
for in-page navigations.
Returns:
event
Eventurl
StringisInPlace
BooleanisMainFrame
BooleanframeProcessId
IntegerframeRoutingId
Integer
Emitted as a server side redirect occurs during navigation. For example a 302 redirect.
This event will be emitted after did-start-navigation
and always before the
did-redirect-navigation
event for the same navigation.
Calling event.preventDefault()
will prevent the navigation (not just the
redirect).
Returns:
event
Eventurl
StringisInPlace
BooleanisMainFrame
BooleanframeProcessId
IntegerframeRoutingId
Integer
Emitted after a server side redirect occurs during navigation. For example a 302 redirect.
This event cannot be prevented, if you want to prevent redirects you should
checkout out the will-redirect
event above.
Returns:
event
Eventurl
StringhttpResponseCode
Integer - -1 for non HTTP navigationshttpStatusText
String - empty for non HTTP navigations
Emitted when a main frame navigation is done.
This event is not emitted for in-page navigations, such as clicking anchor links
or updating the window.location.hash
. Use did-navigate-in-page
event for
this purpose.
Returns:
event
Eventurl
StringhttpResponseCode
Integer - -1 for non HTTP navigationshttpStatusText
String - empty for non HTTP navigations,isMainFrame
BooleanframeProcessId
IntegerframeRoutingId
Integer
Emitted when any frame navigation is done.
This event is not emitted for in-page navigations, such as clicking anchor links
or updating the window.location.hash
. Use did-navigate-in-page
event for
this purpose.
Returns:
event
Eventurl
StringisMainFrame
BooleanframeProcessId
IntegerframeRoutingId
Integer
Emitted when an in-page navigation happened in any frame.
When in-page navigation happens, the page URL changes but does not cause
navigation outside of the page. Examples of this occurring are when anchor links
are clicked or when the DOM hashchange
event is triggered.
Returns:
event
Event
Emitted when a beforeunload
event handler is attempting to cancel a page unload.
Calling event.preventDefault()
will ignore the beforeunload
event handler
and allow the page to be unloaded.
const { BrowserWindow, dialog } = require('electron')
const win = new BrowserWindow({ width: 800, height: 600 })
win.webContents.on('will-prevent-unload', (event) => {
const choice = dialog.showMessageBoxSync(win, {
type: 'question',
buttons: ['Leave', 'Stay'],
title: 'Do you want to leave this site?',
message: 'Changes you made may not be saved.',
defaultId: 0,
cancelId: 1
})
const leave = (choice === 0)
if (leave) {
event.preventDefault()
}
})
Returns:
event
Eventkilled
Boolean
Emitted when the renderer process crashes or is killed.
Deprecated: This event is superceded by the render-process-gone
event
which contains more information about why the render process disappeared. It
isn't always because it crashed. The killed
boolean can be replaced by
checking reason === 'killed'
when you switch to that event.
Returns:
event
Eventdetails
Objectreason
String - The reason the render process is gone. Possible values:clean-exit
- Process exited with an exit code of zeroabnormal-exit
- Process exited with a non-zero exit codekilled
- Process was sent a SIGTERM or otherwise killed externallycrashed
- Process crashedoom
- Process ran out of memorylaunch-failed
- Process never successfully launchedintegrity-failure
- Windows code integrity checks failed
Emitted when the renderer process unexpectedly disappears. This is normally because it was crashed or killed.
Emitted when the web page becomes unresponsive.
Emitted when the unresponsive web page becomes responsive again.
Returns:
event
Eventname
Stringversion
String
Emitted when a plugin process has crashed.
Emitted when webContents
is destroyed.
Returns:
event
Eventinput
Object - Input properties.type
String - EitherkeyUp
orkeyDown
.key
String - Equivalent to KeyboardEvent.key.code
String - Equivalent to KeyboardEvent.code.isAutoRepeat
Boolean - Equivalent to KeyboardEvent.repeat.isComposing
Boolean - Equivalent to KeyboardEvent.isComposing.shift
Boolean - Equivalent to KeyboardEvent.shiftKey.control
Boolean - Equivalent to KeyboardEvent.controlKey.alt
Boolean - Equivalent to KeyboardEvent.altKey.meta
Boolean - Equivalent to KeyboardEvent.metaKey.
Emitted before dispatching the keydown
and keyup
events in the page.
Calling event.preventDefault
will prevent the page keydown
/keyup
events
and the menu shortcuts.
To only prevent the menu shortcuts, use
setIgnoreMenuShortcuts
:
const { BrowserWindow } = require('electron')
const win = new BrowserWindow({ width: 800, height: 600 })
win.webContents.on('before-input-event', (event, input) => {
// For example, only enable application menu keyboard shortcuts when
// Ctrl/Cmd are down.
win.webContents.setIgnoreMenuShortcuts(!input.control && !input.meta)
})
Emitted when the window enters a full-screen state triggered by HTML API.
Emitted when the window leaves a full-screen state triggered by HTML API.
Returns:
event
EventzoomDirection
String - Can bein
orout
.
Emitted when the user is requesting to change the zoom level using the mouse wheel.
Emitted when DevTools is opened.
Emitted when DevTools is closed.
Emitted when DevTools is focused / opened.
Returns:
event
Eventurl
Stringerror
String - The error code.certificate
Certificatecallback
FunctionisTrusted
Boolean - Indicates whether the certificate can be considered trusted.
Emitted when failed to verify the certificate
for url
.
The usage is the same with the certificate-error
event of
app
.
Returns:
event
Eventurl
URLcertificateList
Certificate[]callback
Functioncertificate
Certificate - Must be a certificate from the given list.
Emitted when a client certificate is requested.
The usage is the same with the select-client-certificate
event of
app
.
Returns:
event
EventauthenticationResponseDetails
Objecturl
URL
authInfo
ObjectisProxy
Booleanscheme
Stringhost
Stringport
Integerrealm
String
callback
Functionusername
String (optional)password
String (optional)
Emitted when webContents
wants to do basic auth.
The usage is the same with the login
event of app
.
Returns:
event
Eventresult
ObjectrequestId
IntegeractiveMatchOrdinal
Integer - Position of the active match.matches
Integer - Number of Matches.selectionArea
Rectangle - Coordinates of first match region.finalUpdate
Boolean
Emitted when a result is available for
[webContents.findInPage
] request.
Emitted when media starts playing.
Emitted when media is paused or done playing.
Returns:
event
Eventcolor
(String | null) - Theme color is in format of '#rrggbb'. It isnull
when no theme color is set.
Emitted when a page's theme color changes. This is usually due to encountering a meta tag:
<meta name='theme-color' content='#ff0000'>
Returns:
event
Eventurl
String
Emitted when mouse moves over a link or the keyboard moves the focus to a link.
Returns:
event
Eventtype
Stringimage
NativeImage (optional)scale
Float (optional) - scaling factor for the custom cursor.size
Size (optional) - the size of theimage
.hotspot
Point (optional) - coordinates of the custom cursor's hotspot.
Emitted when the cursor's type changes. The type
parameter can be default
,
crosshair
, pointer
, text
, wait
, help
, e-resize
, n-resize
,
ne-resize
, nw-resize
, s-resize
, se-resize
, sw-resize
, w-resize
,
ns-resize
, ew-resize
, nesw-resize
, nwse-resize
, col-resize
,
row-resize
, m-panning
, e-panning
, n-panning
, ne-panning
, nw-panning
,
s-panning
, se-panning
, sw-panning
, w-panning
, move
, vertical-text
,
cell
, context-menu
, alias
, progress
, nodrop
, copy
, none
,
not-allowed
, zoom-in
, zoom-out
, grab
, grabbing
or custom
.
If the type
parameter is custom
, the image
parameter will hold the custom
cursor image in a NativeImage
, and scale
, size
and hotspot
will hold
additional information about the custom cursor.
Returns:
event
Eventparams
Objectx
Integer - x coordinate.y
Integer - y coordinate.linkURL
String - URL of the link that encloses the node the context menu was invoked on.linkText
String - Text associated with the link. May be an empty string if the contents of the link are an image.pageURL
String - URL of the top level page that the context menu was invoked on.frameURL
String - URL of the subframe that the context menu was invoked on.srcURL
String - Source URL for the element that the context menu was invoked on. Elements with source URLs are images, audio and video.mediaType
String - Type of the node the context menu was invoked on. Can benone
,image
,audio
,video
,canvas
,file
orplugin
.hasImageContents
Boolean - Whether the context menu was invoked on an image which has non-empty contents.isEditable
Boolean - Whether the context is editable.selectionText
String - Text of the selection that the context menu was invoked on.titleText
String - Title or alt text of the selection that the context was invoked on.misspelledWord
String - The misspelled word under the cursor, if any.dictionarySuggestions
String[] - An array of suggested words to show the user to replace themisspelledWord
. Only available if there is a misspelled word and spellchecker is enabled.frameCharset
String - The character encoding of the frame on which the menu was invoked.inputFieldType
String - If the context menu was invoked on an input field, the type of that field. Possible values arenone
,plainText
,password
,other
.menuSourceType
String - Input source that invoked the context menu. Can benone
,mouse
,keyboard
,touch
ortouchMenu
.mediaFlags
Object - The flags for the media element the context menu was invoked on.inError
Boolean - Whether the media element has crashed.isPaused
Boolean - Whether the media element is paused.isMuted
Boolean - Whether the media element is muted.hasAudio
Boolean - Whether the media element has audio.isLooping
Boolean - Whether the media element is looping.isControlsVisible
Boolean - Whether the media element's controls are visible.canToggleControls
Boolean - Whether the media element's controls are toggleable.canRotate
Boolean - Whether the media element can be rotated.
editFlags
Object - These flags indicate whether the renderer believes it is able to perform the corresponding action.canUndo
Boolean - Whether the renderer believes it can undo.canRedo
Boolean - Whether the renderer believes it can redo.canCut
Boolean - Whether the renderer believes it can cut.canCopy
Boolean - Whether the renderer believes it can copycanPaste
Boolean - Whether the renderer believes it can paste.canDelete
Boolean - Whether the renderer believes it can delete.canSelectAll
Boolean - Whether the renderer believes it can select all.
Emitted when there is a new context menu that needs to be handled.
Returns:
event
Eventdevices
BluetoothDevice[]callback
FunctiondeviceId
String
Emitted when bluetooth device needs to be selected on call to
navigator.bluetooth.requestDevice
. To use navigator.bluetooth
api
webBluetooth
should be enabled. If event.preventDefault
is not called,
first available device will be selected. callback
should be called with
deviceId
to be selected, passing empty string to callback
will
cancel the request.
const { app, BrowserWindow } = require('electron')
let win = null
app.commandLine.appendSwitch('enable-experimental-web-platform-features')
app.whenReady().then(() => {
win = new BrowserWindow({ width: 800, height: 600 })
win.webContents.on('select-bluetooth-device', (event, deviceList, callback) => {
event.preventDefault()
const result = deviceList.find((device) => {
return device.deviceName === 'test'
})
if (!result) {
callback('')
} else {
callback(result.deviceId)
}
})
})
Returns:
event
EventdirtyRect
Rectangleimage
NativeImage - The image data of the whole frame.
Emitted when a new frame is generated. Only the dirty area is passed in the buffer.
const { BrowserWindow } = require('electron')
const win = new BrowserWindow({ webPreferences: { offscreen: true } })
win.webContents.on('paint', (event, dirty, image) => {
// updateBitmap(dirty, image.getBitmap())
})
win.loadURL('http://github.com')
Emitted when the devtools window instructs the webContents to reload
Returns:
event
EventwebPreferences
WebPreferences - The web preferences that will be used by the guest page. This object can be modified to adjust the preferences for the guest page.params
Record<string, string> - The other<webview>
parameters such as thesrc
URL. This object can be modified to adjust the parameters of the guest page.
Emitted when a <webview>
's web contents is being attached to this web
contents. Calling event.preventDefault()
will destroy the guest page.
This event can be used to configure webPreferences
for the webContents
of a <webview>
before it's loaded, and provides the ability to set settings
that can't be set via <webview>
attributes.
Note: The specified preload
script option will appear as preloadURL
(not preload
) in the webPreferences
object emitted with this event.
Returns:
event
EventwebContents
WebContents - The guest web contents that is used by the<webview>
.
Emitted when a <webview>
has been attached to this web contents.
Returns:
event
Eventlevel
Integer - The log level, from 0 to 3. In order it matchesverbose
,info
,warning
anderror
.message
String - The actual console messageline
Integer - The line number of the source that triggered this console messagesourceId
String
Emitted when the associated window logs a console message.
Returns:
event
EventpreloadPath
Stringerror
Error
Emitted when the preload script preloadPath
throws an unhandled exception error
.
Returns:
event
Eventchannel
String...args
any[]
Emitted when the renderer process sends an asynchronous message via ipcRenderer.send()
.
Returns:
event
Eventchannel
String...args
any[]
Emitted when the renderer process sends a synchronous message via ipcRenderer.sendSync()
.
Returns:
event
Event
Emitted when desktopCapturer.getSources()
is called in the renderer process.
Calling event.preventDefault()
will make it return empty sources.
Returns:
event
IpcMainEventmoduleName
String
Emitted when remote.require()
is called in the renderer process.
Calling event.preventDefault()
will prevent the module from being returned.
Custom value can be returned by setting event.returnValue
.
Returns:
event
IpcMainEventglobalName
String
Emitted when remote.getGlobal()
is called in the renderer process.
Calling event.preventDefault()
will prevent the global from being returned.
Custom value can be returned by setting event.returnValue
.
Returns:
event
IpcMainEventmoduleName
String
Emitted when remote.getBuiltin()
is called in the renderer process.
Calling event.preventDefault()
will prevent the module from being returned.
Custom value can be returned by setting event.returnValue
.
Returns:
event
IpcMainEvent
Emitted when remote.getCurrentWindow()
is called in the renderer process.
Calling event.preventDefault()
will prevent the object from being returned.
Custom value can be returned by setting event.returnValue
.
Returns:
event
IpcMainEvent
Emitted when remote.getCurrentWebContents()
is called in the renderer process.
Calling event.preventDefault()
will prevent the object from being returned.
Custom value can be returned by setting event.returnValue
.
url
Stringoptions
Object (optional)httpReferrer
(String | Referrer) (optional) - An HTTP Referrer url.userAgent
String (optional) - A user agent originating the request.extraHeaders
String (optional) - Extra headers separated by "\n".postData
(UploadRawData[] | UploadFile[] | UploadBlob[]) (optional)baseURLForDataURL
String (optional) - Base url (with trailing path separator) for files to be loaded by the data url. This is needed only if the specifiedurl
is a data url and needs to load other files.
Returns Promise<void>
- the promise will resolve when the page has finished loading
(see did-finish-load
), and rejects
if the page fails to load (see
did-fail-load
). A noop rejection handler is already attached, which avoids unhandled rejection errors.
Loads the url
in the window. The url
must contain the protocol prefix,
e.g. the http://
or file://
. If the load should bypass http cache then
use the pragma
header to achieve it.
const { webContents } = require('electron')
const options = { extraHeaders: 'pragma: no-cache\n' }
webContents.loadURL('https://github.com', options)
filePath
Stringoptions
Object (optional)query
Record<String, String> (optional) - Passed tourl.format()
.search
String (optional) - Passed tourl.format()
.hash
String (optional) - Passed tourl.format()
.
Returns Promise<void>
- the promise will resolve when the page has finished loading
(see did-finish-load
), and rejects
if the page fails to load (see did-fail-load
).
Loads the given file in the window, filePath
should be a path to
an HTML file relative to the root of your application. For instance
an app structure like this:
| root
| - package.json
| - src
| - main.js
| - index.html
Would require code like this
win.loadFile('src/index.html')
url
String
Initiates a download of the resource at url
without navigating. The
will-download
event of session
will be triggered.
Returns String
- The URL of the current web page.
const { BrowserWindow } = require('electron')
const win = new BrowserWindow({ width: 800, height: 600 })
win.loadURL('http://github.com').then(() => {
const currentURL = win.webContents.getURL()
console.log(currentURL)
})
Returns String
- The title of the current web page.
Returns Boolean
- Whether the web page is destroyed.
Focuses the web page.
Returns Boolean
- Whether the web page is focused.
Returns Boolean
- Whether web page is still loading resources.
Returns Boolean
- Whether the main frame (and not just iframes or frames within it) is
still loading.
Returns Boolean
- Whether the web page is waiting for a first-response from the main
resource of the page.
Stops any pending navigation.
Reloads the current web page.
Reloads current page and ignores cache.
Returns Boolean
- Whether the browser can go back to previous web page.
Returns Boolean
- Whether the browser can go forward to next web page.
offset
Integer
Returns Boolean
- Whether the web page can go to offset
.
Clears the navigation history.
Makes the browser go back a web page.
Makes the browser go forward a web page.
index
Integer
Navigates browser to the specified absolute web page index.
offset
Integer
Navigates to the specified offset from the "current entry".
Returns Boolean
- Whether the renderer process has crashed.
Forcefully terminates the renderer process that is currently hosting this
webContents
. This will cause the render-process-gone
event to be emitted
with the reason=killed || reason=crashed
. Please note that some webContents share renderer
processes and therefore calling this method may also crash the host process
for other webContents as well.
Calling reload()
immediately after calling this
method will force the reload to occur in a new process. This should be used
when this process is unstable or unusable, for instance in order to recover
from the unresponsive
event.
contents.on('unresponsive', async () => {
const { response } = await dialog.showMessageBox({
message: 'App X has become unresponsive',
title: 'Do you want to try forcefully reloading the app?',
buttons: ['OK', 'Cancel'],
cancelId: 1
})
if (response === 0) {
contents.forcefullyCrashRenderer()
contents.reload()
}
})
userAgent
String
Overrides the user agent for this web page.
Returns String
- The user agent for this web page.
css
Stringoptions
Object (optional)cssOrigin
String (optional) - Can be either 'user' or 'author'; Specifying 'user' enables you to prevent websites from overriding the CSS you insert. Default is 'author'.
Returns Promise<String>
- A promise that resolves with a key for the inserted CSS that can later be used to remove the CSS via contents.removeInsertedCSS(key)
.
Injects CSS into the current web page and returns a unique key for the inserted stylesheet.
contents.on('did-finish-load', () => {
contents.insertCSS('html, body { background-color: #f00; }')
})
key
String
Returns Promise<void>
- Resolves if the removal was successful.
Removes the inserted CSS from the current web page. The stylesheet is identified
by its key, which is returned from contents.insertCSS(css)
.
contents.on('did-finish-load', async () => {
const key = await contents.insertCSS('html, body { background-color: #f00; }')
contents.removeInsertedCSS(key)
})
code
StringuserGesture
Boolean (optional) - Default isfalse
.
Returns Promise<any>
- A promise that resolves with the result of the executed code
or is rejected if the result of the code is a rejected promise.
Evaluates code
in page.
In the browser window some HTML APIs like requestFullScreen
can only be
invoked by a gesture from the user. Setting userGesture
to true
will remove
this limitation.
Code execution will be suspended until web page stop loading.
contents.executeJavaScript('fetch("https://jsonplaceholder.typicode.com/users/1").then(resp => resp.json())', true)
.then((result) => {
console.log(result) // Will be the JSON object from the fetch call
})
worldId
Integer - The ID of the world to run the javascript in,0
is the default world,999
is the world used by Electron'scontextIsolation
feature. You can provide any integer here.scripts
WebSource[]userGesture
Boolean (optional) - Default isfalse
.
Returns Promise<any>
- A promise that resolves with the result of the executed code
or is rejected if the result of the code is a rejected promise.
Works like executeJavaScript
but evaluates scripts
in an isolated context.
ignore
Boolean
Ignore application menu shortcuts while this web contents is focused.
muted
Boolean
Mute the audio on the current web page.
Returns Boolean
- Whether this page has been muted.
Returns Boolean
- Whether audio is currently playing.
factor
Double - Zoom factor; default is 1.0.
Changes the zoom factor to the specified factor. Zoom factor is zoom percent divided by 100, so 300% = 3.0.
The factor must be greater than 0.0.
Returns Number
- the current zoom factor.
level
Number - Zoom level.
Changes the zoom level to the specified level. The original size is 0 and each
increment above or below represents zooming 20% larger or smaller to default
limits of 300% and 50% of original size, respectively. The formula for this is
scale := 1.2 ^ level
.
Returns Number
- the current zoom level.
minimumLevel
NumbermaximumLevel
Number
Returns Promise<void>
Sets the maximum and minimum pinch-to-zoom level.
NOTE: Visual zoom is disabled by default in Electron. To re-enable it, call:
contents.setVisualZoomLevelLimits(1, 3)
Executes the editing command undo
in web page.
Executes the editing command redo
in web page.
Executes the editing command cut
in web page.
Executes the editing command copy
in web page.
x
Integery
Integer
Copy the image at the given position to the clipboard.
Executes the editing command paste
in web page.
Executes the editing command pasteAndMatchStyle
in web page.
Executes the editing command delete
in web page.
Executes the editing command selectAll
in web page.
Executes the editing command unselect
in web page.
text
String
Executes the editing command replace
in web page.
text
String
Executes the editing command replaceMisspelling
in web page.
text
String
Returns Promise<void>
Inserts text
to the focused element.
text
String - Content to be searched, must not be empty.options
Object (optional)forward
Boolean (optional) - Whether to search forward or backward, defaults totrue
.findNext
Boolean (optional) - Whether to begin a new text finding session with this request. Should betrue
for initial requests, andfalse
for follow-up requests. Defaults tofalse
.matchCase
Boolean (optional) - Whether search should be case-sensitive, defaults tofalse
.wordStart
Boolean (optional) - Whether to look only at the start of words. defaults tofalse
.medialCapitalAsWordStart
Boolean (optional) - When combined withwordStart
, accepts a match in the middle of a word if the match begins with an uppercase letter followed by a lowercase or non-letter. Accepts several other intra-word matches, defaults tofalse
.
Returns Integer
- The request id used for the request.
Starts a request to find all matches for the text
in the web page. The result of the request
can be obtained by subscribing to found-in-page
event.
action
String - Specifies the action to take place when ending [webContents.findInPage
] request.clearSelection
- Clear the selection.keepSelection
- Translate the selection into a normal selection.activateSelection
- Focus and click the selection node.
Stops any findInPage
request for the webContents
with the provided action
.
const { webContents } = require('electron')
webContents.on('found-in-page', (event, result) => {
if (result.finalUpdate) webContents.stopFindInPage('clearSelection')
})
const requestId = webContents.findInPage('api')
console.log(requestId)
rect
Rectangle (optional) - The area of the page to be captured.
Returns Promise<NativeImage>
- Resolves with a NativeImage
Captures a snapshot of the page within rect
. Omitting rect
will capture the whole visible page.
Returns Boolean
- Whether this page is being captured. It returns true when the capturer count
is large then 0.
contents.incrementCapturerCount([size, stayHidden])
size
Size (optional) - The preferred size for the capturer.stayHidden
Boolean (optional) - Keep the page hidden instead of visible.
Increase the capturer count by one. The page is considered visible when its browser window is
hidden and the capturer count is non-zero. If you would like the page to stay hidden, you should ensure that stayHidden
is set to true.
This also affects the Page Visibility API.
contents.decrementCapturerCount([stayHidden])
stayHidden
Boolean (optional) - Keep the page in hidden state instead of visible.
Decrease the capturer count by one. The page will be set to hidden or occluded state when its
browser window is hidden or occluded and the capturer count reaches zero. If you want to
decrease the hidden capturer count instead you should set stayHidden
to true.
Get the system printer list.
Returns PrinterInfo[]
options
Object (optional)silent
Boolean (optional) - Don't ask user for print settings. Default isfalse
.printBackground
Boolean (optional) - Prints the background color and image of the web page. Default isfalse
.deviceName
String (optional) - Set the printer device name to use. Must be the system-defined name and not the 'friendly' name, e.g 'Brother_QL_820NWB' and not 'Brother QL-820NWB'.color
Boolean (optional) - Set whether the printed web page will be in color or grayscale. Default istrue
.margins
Object (optional)marginType
String (optional) - Can bedefault
,none
,printableArea
, orcustom
. Ifcustom
is chosen, you will also need to specifytop
,bottom
,left
, andright
.top
Number (optional) - The top margin of the printed web page, in pixels.bottom
Number (optional) - The bottom margin of the printed web page, in pixels.left
Number (optional) - The left margin of the printed web page, in pixels.right
Number (optional) - The right margin of the printed web page, in pixels.
landscape
Boolean (optional) - Whether the web page should be printed in landscape mode. Default isfalse
.scaleFactor
Number (optional) - The scale factor of the web page.pagesPerSheet
Number (optional) - The number of pages to print per page sheet.collate
Boolean (optional) - Whether the web page should be collated.copies
Number (optional) - The number of copies of the web page to print.pageRanges
Object[] (optional) - The page range to print. On macOS, only one range is honored.from
Number - Index of the first page to print (0-based).to
Number - Index of the last page to print (inclusive) (0-based).
duplexMode
String (optional) - Set the duplex mode of the printed web page. Can besimplex
,shortEdge
, orlongEdge
.dpi
Record<string, number> (optional)horizontal
Number (optional) - The horizontal dpi.vertical
Number (optional) - The vertical dpi.
header
String (optional) - String to be printed as page header.footer
String (optional) - String to be printed as page footer.pageSize
String | Size (optional) - Specify page size of the printed document. Can beA3
,A4
,A5
,Legal
,Letter
,Tabloid
or an Object containingheight
.
callback
Function (optional)success
Boolean - Indicates success of the print call.failureReason
String - Error description called back if the print fails.
When a custom pageSize
is passed, Chromium attempts to validate platform specific minimum values for width_microns
and height_microns
. Width and height must both be minimum 353 microns but may be higher on some operating systems.
Prints window's web page. When silent
is set to true
, Electron will pick
the system's default printer if deviceName
is empty and the default settings for printing.
Use page-break-before: always;
CSS style to force to print to a new page.
Example usage:
const options = {
silent: true,
deviceName: 'My-Printer',
pageRanges: [{
from: 0,
to: 1
}]
}
win.webContents.print(options, (success, errorType) => {
if (!success) console.log(errorType)
})
options
ObjectheaderFooter
Record<string, string> (optional) - the header and footer for the PDF.title
String - The title for the PDF header.url
String - the url for the PDF footer.
landscape
Boolean (optional) -true
for landscape,false
for portrait.marginsType
Integer (optional) - Specifies the type of margins to use. Uses 0 for default margin, 1 for no margin, and 2 for minimum margin.scaleFactor
Number (optional) - The scale factor of the web page. Can range from 0 to 100.pageRanges
Record<string, number> (optional) - The page range to print.from
Number - Index of the first page to print (0-based).to
Number - Index of the last page to print (inclusive) (0-based).
pageSize
String | Size (optional) - Specify page size of the generated PDF. Can beA3
,A4
,A5
,Legal
,Letter
,Tabloid
or an Object containingheight
andwidth
in microns.printBackground
Boolean (optional) - Whether to print CSS backgrounds.printSelectionOnly
Boolean (optional) - Whether to print selection only.
Returns Promise<Buffer>
- Resolves with the generated PDF data.
Prints window's web page as PDF with Chromium's preview printing custom settings.
The landscape
will be ignored if @page
CSS at-rule is used in the web page.
By default, an empty options
will be regarded as:
{
marginsType: 0,
printBackground: false,
printSelectionOnly: false,
landscape: false,
pageSize: 'A4',
scaleFactor: 100
}
Use page-break-before: always;
CSS style to force to print to a new page.
An example of webContents.printToPDF
:
const { BrowserWindow } = require('electron')
const fs = require('fs')
const path = require('path')
const os = require('os')
const win = new BrowserWindow({ width: 800, height: 600 })
win.loadURL('http://github.com')
win.webContents.on('did-finish-load', () => {
// Use default printing options
win.webContents.printToPDF({}).then(data => {
const pdfPath = path.join(os.homedir(), 'Desktop', 'temp.pdf')
fs.writeFile(pdfPath, data, (error) => {
if (error) throw error
console.log(`Wrote PDF successfully to ${pdfPath}`)
})
}).catch(error => {
console.log(`Failed to write PDF to ${pdfPath}: `, error)
})
})
path
String
Adds the specified path to DevTools workspace. Must be used after DevTools creation:
const { BrowserWindow } = require('electron')
const win = new BrowserWindow()
win.webContents.on('devtools-opened', () => {
win.webContents.addWorkSpace(__dirname)
})
path
String
Removes the specified path from DevTools workspace.
devToolsWebContents
WebContents
Uses the devToolsWebContents
as the target WebContents
to show devtools.
The devToolsWebContents
must not have done any navigation, and it should not
be used for other purposes after the call.
By default Electron manages the devtools by creating an internal WebContents
with native view, which developers have very limited control of. With the
setDevToolsWebContents
method, developers can use any WebContents
to show
the devtools in it, including BrowserWindow
, BrowserView
and <webview>
tag.
Note that closing the devtools does not destroy the devToolsWebContents
, it
is caller's responsibility to destroy devToolsWebContents
.
An example of showing devtools in a <webview>
tag:
<html>
<head>
<style type="text/css">
* { margin: 0; }
#browser { height: 70%; }
#devtools { height: 30%; }
</style>
</head>
<body>
<webview id="browser" src="https://github.com"></webview>
<webview id="devtools" src="about:blank"></webview>
<script>
const { ipcRenderer } = require('electron')
const emittedOnce = (element, eventName) => new Promise(resolve => {
element.addEventListener(eventName, event => resolve(event), { once: true })
})
const browserView = document.getElementById('browser')
const devtoolsView = document.getElementById('devtools')
const browserReady = emittedOnce(browserView, 'dom-ready')
const devtoolsReady = emittedOnce(devtoolsView, 'dom-ready')
Promise.all([browserReady, devtoolsReady]).then(() => {
const targetId = browserView.getWebContentsId()
const devtoolsId = devtoolsView.getWebContentsId()
ipcRenderer.send('open-devtools', targetId, devtoolsId)
})
</script>
</body>
</html>
// Main process
const { ipcMain, webContents } = require('electron')
ipcMain.on('open-devtools', (event, targetContentsId, devtoolsContentsId) => {
const target = webContents.fromId(targetContentsId)
const devtools = webContents.fromId(devtoolsContentsId)
target.setDevToolsWebContents(devtools)
target.openDevTools()
})
An example of showing devtools in a BrowserWindow
:
const { app, BrowserWindow } = require('electron')
let win = null
let devtools = null
app.whenReady().then(() => {
win = new BrowserWindow()
devtools = new BrowserWindow()
win.loadURL('https://github.com')
win.webContents.setDevToolsWebContents(devtools.webContents)
win.webContents.openDevTools({ mode: 'detach' })
})
options
Object (optional)mode
String - Opens the devtools with specified dock state, can beright
,bottom
,undocked
,detach
. Defaults to last used dock state. Inundocked
mode it's possible to dock back. Indetach
mode it's not.activate
Boolean (optional) - Whether to bring the opened devtools window to the foreground. The default istrue
.
Opens the devtools.
When contents
is a <webview>
tag, the mode
would be detach
by default,
explicitly passing an empty mode
can force using last used dock state.
Closes the devtools.
Returns Boolean
- Whether the devtools is opened.
Returns Boolean
- Whether the devtools view is focused .
Toggles the developer tools.
x
Integery
Integer
Starts inspecting element at position (x
, y
).
Opens the developer tools for the shared worker context.
workerId
String
Inspects the shared worker based on its ID.
Returns SharedWorkerInfo[]
- Information about all Shared Workers.
Opens the developer tools for the service worker context.
channel
String...args
any[]
Send an asynchronous message to the renderer process via channel
, along with
arguments. Arguments will be serialized with the Structured Clone
Algorithm, just like postMessage
, so prototype chains will not be
included. Sending Functions, Promises, Symbols, WeakMaps, or WeakSets will
throw an exception.
NOTE: Sending non-standard JavaScript types such as DOM objects or special Electron objects will throw an exception.
The renderer process can handle the message by listening to channel
with the
ipcRenderer
module.
An example of sending messages from the main process to the renderer process: