Learn how to add auto-update capabilities to your Electron application using tools like Electron Updater. This guide will cover setting up update servers, configuring your app to check for and apply updates, and ensuring that users always have the latest version without manual intervention.
Author: saqibkhan
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Which Framework is Right for Your Desktop App?
Compare Electron and NW.js (Node-Webkit), two popular frameworks for building cross-platform desktop applications. This post will highlight their differences, advantages, and disadvantages, helping you choose the best framework based on your project requirements and development preferences.
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How to Use Electron with React: Building a Modern Desktop App
Combine the power of Electron with React to create modern, interactive desktop applications. This article will guide you through setting up a React project within an Electron app, handling state management, and building a user interface. Ideal for developers familiar with React who want to expand into desktop app development.
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Understanding the Main and Renderer Processes in Electron
Delve into the architecture of Electron applications by learning about the main and renderer processes. This post will explain their roles, how they interact, and best practices for managing communication between them using IPC (Inter-Process Communication). Perfect for those looking to understand Electron’s internal workings.
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Setting Up Your First Electron Project: A Step-by-Step Tutorial
Follow this detailed tutorial to create your first Electron application from scratch. We’ll walk you through installing Electron, setting up your project structure, and writing your first lines of code. By the end of this guide, you’ll have a simple, functioning Electron app and an understanding of how to start building more complex applications.
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Building Cross-Platform Desktop Apps with Web Technologies
Explore the basics of Electron, a framework that allows you to build desktop applications using web technologies like JavaScript, HTML, and CSS. This post will cover Electron’s architecture, its core components, and how it enables you to develop applications that work on Windows, macOS, and Linux with a single codebase. Ideal for beginners who are new to desktop app development.
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View
Create and layout native views.
Process: Main
This module cannot be used until the
readyevent of theappmodule is emitted.const { BaseWindow, View } = require('electron')
const win = new BaseWindow()
const view = new View()
view.setBackgroundColor('red')
view.setBounds({ x: 0, y: 0, width: 100, height: 100 })
win.contentView.addChildView(view)Class: View
A basic native view.
Process: Main
Viewis an EventEmitter.new View()Creates a new
View.Instance Events
Objects created with
new Viewemit the following events:Event: ‘bounds-changed’
Emitted when the view’s bounds have changed in response to being laid out. The new bounds can be retrieved with
view.getBounds().Instance Methods
Objects created with
new Viewhave the following instance methods:view.addChildView(view[, index])viewView – Child view to add.indexInteger (optional) – Index at which to insert the child view. Defaults to adding the child at the end of the child list.
If the same View is added to a parent which already contains it, it will be reordered such that it becomes the topmost view.
view.removeChildView(view)viewView – Child view to remove.
view.setBounds(bounds)boundsRectangle – New bounds of the View.
view.getBounds()Returns Rectangle – The bounds of this View, relative to its parent.
view.setBackgroundColor(color)colorstring – Color in Hex, RGB, ARGB, HSL, HSLA or named CSS color format. The alpha channel is optional for the hex type.
Examples of valid
colorvalues:- Hex
#fff(RGB)#ffff(ARGB)#ffffff(RRGGBB)#ffffffff(AARRGGBB)
- RGB
rgb\(([\d]+),\s*([\d]+),\s*([\d]+)\)- e.g.
rgb(255, 255, 255)
- e.g.
- RGBA
rgba\(([\d]+),\s*([\d]+),\s*([\d]+),\s*([\d.]+)\)- e.g.
rgba(255, 255, 255, 1.0)
- e.g.
- HSL
hsl\((-?[\d.]+),\s*([\d.]+)%,\s*([\d.]+)%\)- e.g.
hsl(200, 20%, 50%)
- e.g.
- HSLA
hsla\((-?[\d.]+),\s*([\d.]+)%,\s*([\d.]+)%,\s*([\d.]+)\)- e.g.
hsla(200, 20%, 50%, 0.5)
- e.g.
- Color name
- Options are listed in SkParseColor.cpp
- Similar to CSS Color Module Level 3 keywords, but case-sensitive.
- e.g.
bluevioletorred
- e.g.
Note: Hex format with alpha takes
AARRGGBBorARGB, notRRGGBBAAorRGB.view.setVisible(visible)visibleboolean – If false, the view will be hidden from display.
Instance Properties
Objects created with
new Viewhave the following properties:view.childrenReadonlyA
View[]property representing the child views of this view. -
WebFrameMain
Control web pages and iframes.
Process: Main
The
webFrameMainmodule can be used to lookup frames across existingWebContentsinstances. Navigation events are the common use case.const { BrowserWindow, webFrameMain } = require('electron')
const win = new BrowserWindow({ width: 800, height: 1500 })
win.loadURL('https://twitter.com')
win.webContents.on(
'did-frame-navigate',
(event, url, httpResponseCode, httpStatusText, isMainFrame, frameProcessId, frameRoutingId) => {
const frame = webFrameMain.fromId(frameProcessId, frameRoutingId)
if (frame) {
const code = 'document.body.innerHTML = document.body.innerHTML.replaceAll("heck", "h*ck")'
frame.executeJavaScript(code)
}
}
)You can also access frames of existing pages by using the
mainFrameproperty ofWebContents.const { BrowserWindow } = require('electron')
async function main () {
const win = new BrowserWindow({ width: 800, height: 600 })
await win.loadURL('https://reddit.com')
const youtubeEmbeds = win.webContents.mainFrame.frames.filter((frame) => {
try {
const url = new URL(frame.url)
return url.host === 'www.youtube.com'
} catch {
return false
}
})
console.log(youtubeEmbeds)
}
main()Methods
These methods can be accessed from the
webFrameMainmodule:webFrameMain.fromId(processId, routingId)processIdInteger – AnIntegerrepresenting the internal ID of the process which owns the frame.routingIdInteger – AnIntegerrepresenting the unique frame ID in the current renderer process. Routing IDs can be retrieved fromWebFrameMaininstances (frame.routingId) and are also passed by frame specificWebContentsnavigation events (e.g.did-frame-navigate).
Returns
WebFrameMain | undefined– A frame with the given process and routing IDs, orundefinedif there is no WebFrameMain associated with the given IDs.Class: WebFrameMain
Process: Main
This class is not exported from the'electron'module. It is only available as a return value of other methods in the Electron API.Instance Events
Event: ‘dom-ready’
Emitted when the document is loaded.
Instance Methods
frame.executeJavaScript(code[, userGesture])codestringuserGestureboolean (optional) – Default isfalse.
Returns
Promise<unknown>– A promise that resolves with the result of the executed code or is rejected if execution throws or results in a rejected promise.Evaluates
codein page.In the browser window some HTML APIs like
requestFullScreencan only be invoked by a gesture from the user. SettinguserGesturetotruewill remove this limitation.frame.reload()Returns
boolean– Whether the reload was initiated successfully. Only results infalsewhen the frame has no history.frame.send(channel, ...args)channelstring...argsany[]
Send an asynchronous message to the renderer process via
channel, along with arguments. Arguments will be serialized with the Structured Clone Algorithm, just likepostMessage, so prototype chains will not be included. Sending Functions, Promises, Symbols, WeakMaps, or WeakSets will throw an exception.The renderer process can handle the message by listening to
channelwith theipcRenderermodule.frame.postMessage(channel, message, [transfer])channelstringmessageanytransferMessagePortMain[] (optional)
Send a message to the renderer process, optionally transferring ownership of zero or more
MessagePortMainobjects.The transferred
MessagePortMainobjects will be available in the renderer process by accessing theportsproperty of the emitted event. When they arrive in the renderer, they will be native DOMMessagePortobjects.For example:
// Main process
const win = new BrowserWindow()
const { port1, port2 } = new MessageChannelMain()
win.webContents.mainFrame.postMessage('port', { message: 'hello' }, [port1])
// Renderer process
ipcRenderer.on('port', (e, msg) => {
const [port] = e.ports
// ...
})Instance Properties
frame.ipcReadonlyAn
IpcMaininstance scoped to the frame.IPC messages sent with
ipcRenderer.send,ipcRenderer.sendSyncoripcRenderer.postMessagewill be delivered in the following order:contents.on('ipc-message')contents.mainFrame.on(channel)contents.ipc.on(channel)ipcMain.on(channel)
Handlers registered with
invokewill be checked in the following order. The first one that is defined will be called, the rest will be ignored.contents.mainFrame.handle(channel)contents.handle(channel)ipcMain.handle(channel)
In most cases, only the main frame of a WebContents can send or receive IPC messages. However, if the
nodeIntegrationInSubFramesoption is enabled, it is possible for child frames to send and receive IPC messages also. TheWebContents.ipcinterface may be more convenient whennodeIntegrationInSubFramesis not enabled.frame.urlReadonlyA
stringrepresenting the current URL of the frame.frame.originReadonlyA
stringrepresenting the current origin of the frame, serialized according to RFC 6454. This may be different from the URL. For instance, if the frame is a child window opened toabout:blank, thenframe.originwill return the parent frame’s origin, whileframe.urlwill return the empty string. Pages without a scheme/host/port triple origin will have the serialized origin of"null"(that is, the string containing the letters n, u, l, l).frame.topReadonlyA
WebFrameMain | nullrepresenting top frame in the frame hierarchy to whichframebelongs.frame.parentReadonlyA
WebFrameMain | nullrepresenting parent frame offrame, the property would benullifframeis the top frame in the frame hierarchy.frame.framesReadonlyA
WebFrameMain[]collection containing the direct descendents offrame.frame.framesInSubtreeReadonlyA
WebFrameMain[]collection containing every frame in the subtree offrame, including itself. This can be useful when traversing through all frames.frame.frameTreeNodeIdReadonlyAn
Integerrepresenting the id of the frame’s internal FrameTreeNode instance. This id is browser-global and uniquely identifies a frame that hosts content. The identifier is fixed at the creation of the frame and stays constant for the lifetime of the frame. When the frame is removed, the id is not used again.frame.nameReadonlyA
stringrepresenting the frame name.frame.osProcessIdReadonlyAn
Integerrepresenting the operating systempidof the process which owns this frame.frame.processIdReadonlyAn
Integerrepresenting the Chromium internalpidof the process which owns this frame. This is not the same as the OS process ID; to read that useframe.osProcessId.frame.routingIdReadonlyAn
Integerrepresenting the unique frame id in the current renderer process. DistinctWebFrameMaininstances that refer to the same underlying frame will have the sameroutingId.frame.visibilityStateReadonlyA
stringrepresenting the visibility state of the frame.See also how the Page Visibility API is affected by other Electron APIs.
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WebContentsView
A View that displays a WebContents.
Process: Main
This module cannot be used until the
readyevent of theappmodule is emitted.const { BaseWindow, WebContentsView } = require('electron')
const win = new BaseWindow({ width: 800, height: 400 })
const view1 = new WebContentsView()
win.contentView.addChildView(view1)
view1.webContents.loadURL('https://electronjs.org')
view1.setBounds({ x: 0, y: 0, width: 400, height: 400 })
const view2 = new WebContentsView()
win.contentView.addChildView(view2)
view2.webContents.loadURL('https://github.com/electron/electron')
view2.setBounds({ x: 400, y: 0, width: 400, height: 400 })Class: WebContentsView extends
ViewA View that displays a WebContents.
Process: Main
WebContentsViewinherits fromView.WebContentsViewis an EventEmitter.new WebContentsView([options])optionsObject (optional)webPreferencesWebPreferences (optional) – Settings of web page’s features.webContentsWebContents (optional) – If present, the given WebContents will be adopted by the WebContentsView. A WebContents may only be presented in one WebContentsView at a time.
Creates a WebContentsView.
Instance Properties
Objects created with
new WebContentsViewhave the following properties, in addition to those inherited from View:view.webContentsReadonlyA
WebContentsproperty containing a reference to the displayedWebContents. Use this to interact with theWebContents, for instance to load a URL.const { WebContentsView } = require('electron')
const view = new WebContentsView()
view.webContents.loadURL('https://electronjs.org/') -
WebContents
Render and control web pages.
Process: Main
webContentsis an EventEmitter. It is responsible for rendering and controlling a web page and is a property of theBrowserWindowobject. An example of accessing thewebContentsobject:const { BrowserWindow } = require('electron')
const win = new BrowserWindow({ width: 800, height: 1500 })
win.loadURL('https://github.com')
const contents = win.webContents
console.log(contents)Navigation Events
Several events can be used to monitor navigations as they occur within a
webContents.Document Navigations
When a
webContentsnavigates to another page (as opposed to an in-page navigation), the following events will be fired.did-start-navigationwill-frame-navigatewill-navigate(only fired when main frame navigates)will-redirect(only fired when a redirect happens during navigation)did-redirect-navigation(only fired when a redirect happens during navigation)did-frame-navigatedid-navigate(only fired when main frame navigates)
Subsequent events will not fire if
event.preventDefault()is called on any of the cancellable events.In-page Navigation
In-page navigations don’t cause the page to reload, but instead navigate to a location within the current page. These events are not cancellable. For an in-page navigations, the following events will fire in this order:
Frame Navigation
The
will-navigateanddid-navigateevents only fire when the mainFrame navigates. If you want to also observe navigations in<iframe>s, usewill-frame-navigateanddid-frame-navigateevents.Methods
These methods can be accessed from the
webContentsmodule:const { webContents } = require('electron')
console.log(webContents)webContents.getAllWebContents()Returns
WebContents[]– An array of allWebContentsinstances. This will contain web contents for all windows, webviews, opened devtools, and devtools extension background pages.webContents.getFocusedWebContents()Returns
WebContents | null– The web contents that is focused in this application, otherwise returnsnull.webContents.fromId(id)idInteger
Returns
WebContents | undefined– A WebContents instance with the given ID, orundefinedif there is no WebContents associated with the given ID.webContents.fromFrame(frame)frameWebFrameMain
Returns
WebContents | undefined– A WebContents instance with the given WebFrameMain, orundefinedif there is no WebContents associated with the given WebFrameMain.webContents.fromDevToolsTargetId(targetId)targetIdstring – The Chrome DevTools Protocol TargetID associated with the WebContents instance.
Returns
WebContents | undefined– A WebContents instance with the given TargetID, orundefinedif there is no WebContents associated with the given TargetID.When communicating with the Chrome DevTools Protocol, it can be useful to lookup a WebContents instance based on its assigned TargetID.
async function lookupTargetId (browserWindow) {
const wc = browserWindow.webContents
await wc.debugger.attach('1.3')
const { targetInfo } = await wc.debugger.sendCommand('Target.getTargetInfo')
const { targetId } = targetInfo
const targetWebContents = await wc.fromDevToolsTargetId(targetId)
}Class: WebContents
Render and control the contents of a BrowserWindow instance.
Process: Main
This class is not exported from the'electron'module. It is only available as a return value of other methods in the Electron API.Instance Events
Event: ‘did-finish-load’
Emitted when the navigation is done, i.e. the spinner of the tab has stopped spinning, and the
onloadevent was dispatched.Event: ‘did-fail-load’
Returns:
eventEventerrorCodeIntegererrorDescriptionstringvalidatedURLstringisMainFramebooleanframeProcessIdIntegerframeRoutingIdInteger
This event is like
did-finish-loadbut emitted when the load failed. The full list of error codes and their meaning is available here.Event: ‘did-fail-provisional-load’
Returns:
eventEventerrorCodeIntegererrorDescriptionstringvalidatedURLstringisMainFramebooleanframeProcessIdIntegerframeRoutingIdInteger
This event is like
did-fail-loadbut emitted when the load was cancelled (e.g.window.stop()was invoked).Event: ‘did-frame-finish-load’
Returns:
eventEventisMainFramebooleanframeProcessIdIntegerframeRoutingIdInteger
Emitted when a frame has done navigation.
Event: ‘did-start-loading’
Corresponds to the points in time when the spinner of the tab started spinning.
Event: ‘did-stop-loading’
Corresponds to the points in time when the spinner of the tab stopped spinning.
Event: ‘dom-ready’
Emitted when the document in the top-level frame is loaded.
Event: ‘page-title-updated’
Returns:
eventEventtitlestringexplicitSetboolean
Fired when page title is set during navigation.
explicitSetis false when title is synthesized from file url.Event: ‘page-favicon-updated’
Returns:
eventEventfaviconsstring[] – Array of URLs.
Emitted when page receives favicon urls.
Event: ‘content-bounds-updated’
Returns:
eventEventboundsRectangle – requested new content bounds
Emitted when the page calls
window.moveTo,window.resizeToor related APIs.By default, this will move the window. To prevent that behavior, call
event.preventDefault().Event: ‘did-create-window’
Returns:
windowBrowserWindowdetailsObjecturlstring – URL for the created window.frameNamestring – Name given to the created window in thewindow.open()call.optionsBrowserWindowConstructorOptions – The options used to create the BrowserWindow. They are merged in increasing precedence: parsed options from thefeaturesstring fromwindow.open(), security-related webPreferences inherited from the parent, and options given bywebContents.setWindowOpenHandler. Unrecognized options are not filtered out.referrerReferrer – The referrer that will be passed to the new window. May or may not result in theRefererheader being sent, depending on the referrer policy.postBodyPostBody (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.dispositionstring – Can bedefault,foreground-tab,background-tab,new-windoworother.
Emitted after successful creation of a window via
window.openin the renderer. Not emitted if the creation of the window is canceled fromwebContents.setWindowOpenHandler.See
window.open()for more details and how to use this in conjunction withwebContents.setWindowOpenHandler.Event: ‘will-navigate’
Returns:
detailsEvent<>urlstring – The URL the frame is navigating to.isSameDocumentboolean – This event does not fire for same document navigations using window.history api and reference fragment navigations. This property is always set tofalsefor this event.isMainFrameboolean – True if the navigation is taking place in a main frame.frameWebFrameMain – The frame to be navigated.initiatorWebFrameMain (optional) – The frame which initiated the navigation, which can be a parent frame (e.g. viawindow.openwith a frame’s name), or null if the navigation was not initiated by a frame. This can also be null if the initiating frame was deleted before the event was emitted.
urlstring DeprecatedisInPlaceboolean DeprecatedisMainFrameboolean DeprecatedframeProcessIdInteger DeprecatedframeRoutingIdInteger Deprecated
Emitted when a user or the page wants to start navigation on the main frame. It can happen when the
window.locationobject 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.loadURLandwebContents.back.It is also not emitted for in-page navigations, such as clicking anchor links or updating the
window.location.hash. Usedid-navigate-in-pageevent for this purpose.Calling
event.preventDefault()will prevent the navigation.Event: ‘will-frame-navigate’
Returns:
detailsEvent<>urlstring – The URL the frame is navigating to.isSameDocumentboolean – This event does not fire for same document navigations using window.history api and reference fragment navigations. This property is always set tofalsefor this event.isMainFrameboolean – True if the navigation is taking place in a main frame.frameWebFrameMain – The frame to be navigated.initiatorWebFrameMain (optional) – The frame which initiated the navigation, which can be a parent frame (e.g. viawindow.openwith a frame’s name), or null if the navigation was not initiated by a frame. This can also be null if the initiating frame was deleted before the event was emitted.
Emitted when a user or the page wants to start navigation in any frame. It can happen when the
window.locationobject is changed or a user clicks a link in the page.Unlike
will-navigate,will-frame-navigateis fired when the main frame or any of its subframes attempts to navigate. When the navigation event comes from the main frame,isMainFramewill betrue.This event will not emit when the navigation is started programmatically with APIs like
webContents.loadURLandwebContents.back.It is also not emitted for in-page navigations, such as clicking anchor links or updating the
window.location.hash. Usedid-navigate-in-pageevent for this purpose.Calling
event.preventDefault()will prevent the navigation.Event: ‘did-start-navigation’
Returns:
detailsEvent<>urlstring – The URL the frame is navigating to.isSameDocumentboolean – Whether the navigation happened without changing document. Examples of same document navigations are reference fragment navigations, pushState/replaceState, and same page history navigation.isMainFrameboolean – True if the navigation is taking place in a main frame.frameWebFrameMain – The frame to be navigated.initiatorWebFrameMain (optional) – The frame which initiated the navigation, which can be a parent frame (e.g. viawindow.openwith a frame’s name), or null if the navigation was not initiated by a frame. This can also be null if the initiating frame was deleted before the event was emitted.
urlstring DeprecatedisInPlaceboolean DeprecatedisMainFrameboolean DeprecatedframeProcessIdInteger DeprecatedframeRoutingIdInteger Deprecated
Emitted when any frame (including main) starts navigating.
Event: ‘will-redirect’
Returns:
detailsEvent<>urlstring – The URL the frame is navigating to.isSameDocumentboolean – Whether the navigation happened without changing document. Examples of same document navigations are reference fragment navigations, pushState/replaceState, and same page history navigation.isMainFrameboolean – True if the navigation is taking place in a main frame.frameWebFrameMain – The frame to be navigated.initiatorWebFrameMain (optional) – The frame which initiated the navigation, which can be a parent frame (e.g. viawindow.openwith a frame’s name), or null if the navigation was not initiated by a frame. This can also be null if the initiating frame was deleted before the event was emitted.
urlstring DeprecatedisInPlaceboolean DeprecatedisMainFrameboolean DeprecatedframeProcessIdInteger DeprecatedframeRoutingIdInteger Deprecated
Emitted when a server side redirect occurs during navigation. For example a 302 redirect.
This event will be emitted after
did-start-navigationand always before thedid-redirect-navigationevent for the same navigation.Calling
event.preventDefault()will prevent the navigation (not just the redirect).Event: ‘did-redirect-navigation’
Returns:
detailsEvent<>urlstring – The URL the frame is navigating to.isSameDocumentboolean – Whether the navigation happened without changing document. Examples of same document navigations are reference fragment navigations, pushState/replaceState, and same page history navigation.isMainFrameboolean – True if the navigation is taking place in a main frame.frameWebFrameMain – The frame to be navigated.initiatorWebFrameMain (optional) – The frame which initiated the navigation, which can be a parent frame (e.g. viawindow.openwith a frame’s name), or null if the navigation was not initiated by a frame. This can also be null if the initiating frame was deleted before the event was emitted.
urlstring DeprecatedisInPlaceboolean DeprecatedisMainFrameboolean DeprecatedframeProcessIdInteger DeprecatedframeRoutingIdInteger Deprecated
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-redirectevent above.Event: ‘did-navigate’
Returns:
eventEventurlstringhttpResponseCodeInteger – -1 for non HTTP navigationshttpStatusTextstring – 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. Usedid-navigate-in-pageevent for this purpose.Event: ‘did-frame-navigate’
Returns:
eventEventurlstringhttpResponseCodeInteger – -1 for non HTTP navigationshttpStatusTextstring – empty for non HTTP navigations,isMainFramebooleanframeProcessIdIntegerframeRoutingIdInteger
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. Usedid-navigate-in-pageevent for this purpose.Event: ‘did-navigate-in-page’
Returns:
eventEventurlstringisMainFramebooleanframeProcessIdIntegerframeRoutingIdInteger
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
hashchangeevent is triggered.Event: ‘will-prevent-unload’
Returns:
eventEvent
Emitted when a
beforeunloadevent handler is attempting to cancel a page unload.Calling
event.preventDefault()will ignore thebeforeunloadevent 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()
}
})Note: This will be emitted for
BrowserViewsbut will not be respected – this is because we have chosen not to tie theBrowserViewlifecycle to its owning BrowserWindow should one exist per the specification.Event: ‘render-process-gone’
Returns:
eventEventdetailsRenderProcessGoneDetails
Emitted when the renderer process unexpectedly disappears. This is normally because it was crashed or killed.
Event: ‘unresponsive’
Emitted when the web page becomes unresponsive.
Event: ‘responsive’
Emitted when the unresponsive web page becomes responsive again.
Event: ‘plugin-crashed’
Returns:
eventEventnamestringversionstring
Emitted when a plugin process has crashed.
Event: ‘destroyed’
Emitted when
webContentsis destroyed.Event: ‘input-event’
Returns:
eventEventinputEventInputEvent
Emitted when an input event is sent to the WebContents. See InputEvent for details.
Event: ‘before-input-event’
Returns:
eventEventinputObject – Input properties.typestring – EitherkeyUporkeyDown.keystring – Equivalent to KeyboardEvent.key.codestring – Equivalent to KeyboardEvent.code.isAutoRepeatboolean – Equivalent to KeyboardEvent.repeat.isComposingboolean – Equivalent to KeyboardEvent.isComposing.shiftboolean – Equivalent to KeyboardEvent.shiftKey.controlboolean – Equivalent to KeyboardEvent.controlKey.altboolean – Equivalent to KeyboardEvent.altKey.metaboolean – Equivalent to KeyboardEvent.metaKey.locationnumber – Equivalent to KeyboardEvent.location.modifiersstring[] – See InputEvent.modifiers.
Emitted before dispatching the
keydownandkeyupevents in the page. Callingevent.preventDefaultwill prevent the pagekeydown/keyupevents 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)
})Event: ‘enter-html-full-screen’
Emitted when the window enters a full-screen state triggered by HTML API.
Event: ‘leave-html-full-screen’
Emitted when the window leaves a full-screen state triggered by HTML API.
Event: ‘zoom-changed’
Returns:
eventEventzoomDirectionstring – Can beinorout.
Emitted when the user is requesting to change the zoom level using the mouse wheel.
Event: ‘blur’
Emitted when the
WebContentsloses focus.Event: ‘focus’
Emitted when the
WebContentsgains focus.Note that on macOS, having focus means the
WebContentsis the first responder of window, so switching focus between windows would not trigger thefocusandblurevents ofWebContents, as the first responder of each window is not changed.The
focusandblurevents ofWebContentsshould only be used to detect focus change between differentWebContentsandBrowserViewin the same window.Event: ‘devtools-open-url’
Returns:
eventEventurlstring – URL of the link that was clicked or selected.
Emitted when a link is clicked in DevTools or ‘Open in new tab’ is selected for a link in its context menu.
Event: ‘devtools-search-query’
Returns:
eventEventquerystring – text to query for.
Emitted when ‘Search’ is selected for text in its context menu.
Event: ‘devtools-opened’
Emitted when DevTools is opened.
Event: ‘devtools-closed’
Emitted when DevTools is closed.
Event: ‘devtools-focused’
Emitted when DevTools is focused / opened.
Event: ‘certificate-error’
Returns:
eventEventurlstringerrorstring – The error code.certificateCertificatecallbackFunctionisTrustedboolean – Indicates whether the certificate can be considered trusted.
isMainFrameboolean
Emitted when failed to verify the
certificateforurl.The usage is the same with the
certificate-errorevent ofapp.Event: ‘select-client-certificate’
Returns:
eventEventurlURLcertificateListCertificate[]callbackFunctioncertificateCertificate – Must be a certificate from the given list.
Emitted when a client certificate is requested.
The usage is the same with the
select-client-certificateevent ofapp.Event: ‘login’
Returns:
eventEventauthenticationResponseDetailsObjecturlURL
authInfoObjectisProxybooleanschemestringhoststringportIntegerrealmstring
callbackFunctionusernamestring (optional)passwordstring (optional)
Emitted when
webContentswants to do basic auth.The usage is the same with the
loginevent ofapp.Event: ‘found-in-page’
Returns:
eventEventresultObjectrequestIdIntegeractiveMatchOrdinalInteger – Position of the active match.matchesInteger – Number of Matches.selectionAreaRectangle – Coordinates of first match region.finalUpdateboolean
Emitted when a result is available for
webContents.findInPagerequest.Event: ‘media-started-playing’
Emitted when media starts playing.
Event: ‘media-paused’
Emitted when media is paused or done playing.
Event: ‘audio-state-changed’
Returns:
eventEvent<>audibleboolean – True if one or more frames or childwebContentsare emitting audio.
Emitted when media becomes audible or inaudible.
Event: ‘did-change-theme-color’
Returns:
eventEventcolor(string | null) – Theme color is in format of ‘#rrggbb’. It isnullwhen 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'>Event: ‘update-target-url’
Returns:
eventEventurlstring
Emitted when mouse moves over a link or the keyboard moves the focus to a link.
Event: ‘cursor-changed’
Returns:
eventEventtypestringimageNativeImage (optional)scaleFloat (optional) – scaling factor for the custom cursor.sizeSize (optional) – the size of theimage.hotspotPoint (optional) – coordinates of the custom cursor’s hotspot.
Emitted when the cursor’s type changes. The
typeparameter can bepointer,crosshair,hand,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,m-panning-vertical,m-panning-horizontal,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,custom,null,drag-drop-none,drag-drop-move,drag-drop-copy,drag-drop-link,ns-no-resize,ew-no-resize,nesw-no-resize,nwse-no-resize, ordefault.If the
typeparameter iscustom, theimageparameter will hold the custom cursor image in aNativeImage, andscale,sizeandhotspotwill hold additional information about the custom cursor.Event: ‘context-menu’
Returns:
eventEventparamsObjectxInteger – x coordinate.yInteger – y coordinate.frameWebFrameMain – Frame from which the context menu was invoked.linkURLstring – URL of the link that encloses the node the context menu was invoked on.linkTextstring – Text associated with the link. May be an empty string if the contents of the link are an image.pageURLstring – URL of the top level page that the context menu was invoked on.frameURLstring – URL of the subframe that the context menu was invoked on.srcURLstring – Source URL for the element that the context menu was invoked on. Elements with source URLs are images, audio and video.mediaTypestring – Type of the node the context menu was invoked on. Can benone,image,audio,video,canvas,fileorplugin.hasImageContentsboolean – Whether the context menu was invoked on an image which has non-empty contents.isEditableboolean – Whether the context is editable.selectionTextstring – Text of the selection that the context menu was invoked on.titleTextstring – Title text of the selection that the context menu was invoked on.altTextstring – Alt text of the selection that the context menu was invoked on.suggestedFilenamestring – Suggested filename to be used when saving file through ‘Save Link As’ option of context menu.selectionRectRectangle – Rect representing the coordinates in the document space of the selection.selectionStartOffsetnumber – Start position of the selection text.referrerPolicyReferrer – The referrer policy of the frame on which the menu is invoked.misspelledWordstring – The misspelled word under the cursor, if any.dictionarySuggestionsstring[] – An array of suggested words to show the user to replace themisspelledWord. Only available if there is a misspelled word and spellchecker is enabled.frameCharsetstring – The character encoding of the frame on which the menu was invoked.formControlTypestring – The source that the context menu was invoked on. Possible values includenone,button-button,field-set,input-button,input-checkbox,input-color,input-date,input-datetime-local,input-email,input-file,input-hidden,input-image,input-month,input-number,input-password,input-radio,input-range,input-reset,input-search,input-submit,input-telephone,input-text,input-time,input-url,input-week,output,reset-button,select-list,select-list,select-multiple,select-one,submit-button, andtext-area,spellcheckEnabledboolean – If the context is editable, whether or not spellchecking is enabled.menuSourceTypestring – Input source that invoked the context menu. Can benone,mouse,keyboard,touch,touchMenu,longPress,longTap,touchHandle,stylus,adjustSelection, oradjustSelectionReset.mediaFlagsObject – The flags for the media element the context menu was invoked on.inErrorboolean – Whether the media element has crashed.isPausedboolean – Whether the media element is paused.isMutedboolean – Whether the media element is muted.hasAudioboolean – Whether the media element has audio.isLoopingboolean – Whether the media element is looping.isControlsVisibleboolean – Whether the media element’s controls are visible.canToggleControlsboolean – Whether the media element’s controls are toggleable.canPrintboolean – Whether the media element can be printed.canSaveboolean – Whether or not the media element can be downloaded.canShowPictureInPictureboolean – Whether the media element can show picture-in-picture.isShowingPictureInPictureboolean – Whether the media element is currently showing picture-in-picture.canRotateboolean – Whether the media element can be rotated.canLoopboolean – Whether the media element can be looped.
editFlagsObject – These flags indicate whether the renderer believes it is able to perform the corresponding action.canUndoboolean – Whether the renderer believes it can undo.canRedoboolean – Whether the renderer believes it can redo.canCutboolean – Whether the renderer believes it can cut.canCopyboolean – Whether the renderer believes it can copy.canPasteboolean – Whether the renderer believes it can paste.canDeleteboolean – Whether the renderer believes it can delete.canSelectAllboolean – Whether the renderer believes it can select all.canEditRichlyboolean – Whether the renderer believes it can edit text richly.
Emitted when there is a new context menu that needs to be handled.
Event: ‘select-bluetooth-device’
Returns:
eventEventdevicesBluetoothDevice[]callbackFunctiondeviceIdstring
Emitted when a bluetooth device needs to be selected when a call to
navigator.bluetooth.requestDeviceis made.callbackshould be called with thedeviceIdof the device to be selected. Passing an empty string tocallbackwill cancel the request.If an event listener is not added for this event, or if
event.preventDefaultis not called when handling this event, the first available device will be automatically selected.Due to the nature of bluetooth, scanning for devices when
navigator.bluetooth.requestDeviceis called may take time and will causeselect-bluetooth-deviceto fire multiple times untilcallbackis called with either a device id or an empty string to cancel the request.main.js
const { app, BrowserWindow } = require('electron')
let win = null
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) {
// The device wasn't found so we need to either wait longer (eg until the
// device is turned on) or cancel the request by calling the callback
// with an empty string.
callback('')
} else {
callback(result.deviceId)
}
})
})Event: ‘paint’
Returns:
eventEventdirtyRectRectangleimageNativeImage – 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('https://github.com')Event: ‘devtools-reload-page’
Emitted when the devtools window instructs the webContents to reload
Event: ‘will-attach-webview’
Returns:
eventEventwebPreferencesWebPreferences – The web preferences that will be used by the guest page. This object can be modified to adjust the preferences for the guest page.paramsRecord<string, string> – The other<webview>parameters such as thesrcURL. 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. Callingevent.preventDefault()will destroy the guest page.This event can be used to configure
webPreferencesfor thewebContentsof a<webview>before it’s loaded, and provides the ability to set settings that can’t be set via<webview>attributes.Event: ‘did-attach-webview’
Returns:
eventEventwebContentsWebContents – The guest web contents that is used by the<webview>.
Emitted when a
<webview>has been attached to this web contents.Event: ‘console-message’
Returns:
eventEventlevelInteger – The log level, from 0 to 3. In order it matchesverbose,info,warninganderror.messagestring – The actual console messagelineInteger – The line number of the source that triggered this console messagesourceIdstring
Emitted when the associated window logs a console message.
Event: ‘preload-error’
Returns:
eventEventpreloadPathstringerrorError
Emitted when the preload script
preloadPaththrows an unhandled exceptionerror.Event: ‘ipc-message’
Returns:
eventIpcMainEventchannelstring...argsany[]
Emitted when the renderer process sends an asynchronous message via
ipcRenderer.send().See also
webContents.ipc, which provides anIpcMain-like interface for responding to IPC messages specifically from this WebContents.Event: ‘ipc-message-sync’
Returns:
eventIpcMainEventchannelstring...argsany[]
Emitted when the renderer process sends a synchronous message via
ipcRenderer.sendSync().See also
webContents.ipc, which provides anIpcMain-like interface for responding to IPC messages specifically from this WebContents.Event: ‘preferred-size-changed’
Returns:
eventEventpreferredSizeSize – The minimum size needed to contain the layout of the document—without requiring scrolling.
Emitted when the
WebContentspreferred size has changed.This event will only be emitted when
enablePreferredSizeModeis set totrueinwebPreferences.Event: ‘frame-created’
Returns:
eventEventdetailsObjectframeWebFrameMain
Emitted when the mainFrame, an
<iframe>, or a nested<iframe>is loaded within the page.Instance Methods
contents.loadURL(url[, options])urlstringoptionsObject (optional)httpReferrer(string | Referrer) (optional) – An HTTP Referrer url.userAgentstring (optional) – A user agent originating the request.extraHeadersstring (optional) – Extra headers separated by “\n”.postData(UploadRawData | UploadFile)[] (optional)baseURLForDataURLstring (optional) – Base url (with trailing path separator) for files to be loaded by the data url. This is needed only if the specifiedurlis a data url and needs to load other files.
Returns
Promise<void>– the promise will resolve when the page has finished loading (seedid-finish-load), and rejects if the page fails to load (seedid-fail-load). A noop rejection handler is already attached, which avoids unhandled rejection errors.Loads the
urlin the window. Theurlmust contain the protocol prefix, e.g. thehttp://orfile://. If the load should bypass http cache then use thepragmaheader to achieve it.const win = new BrowserWindow()
const options = { extraHeaders: 'pragma: no-cache\n' }
win.webContents.loadURL('https://github.com', options)contents.loadFile(filePath[, options])filePathstringoptionsObject (optional)queryRecord<string, string> (optional) – Passed tourl.format().searchstring (optional) – Passed tourl.format().hashstring (optional) – Passed tourl.format().
Returns
Promise<void>– the promise will resolve when the page has finished loading (seedid-finish-load), and rejects if the page fails to load (seedid-fail-load).Loads the given file in the window,
filePathshould 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.htmlWould require code like this
const win = new BrowserWindow()
win.loadFile('src/index.html')contents.downloadURL(url[, options])urlstringoptionsObject (optional)headersRecord<string, string> (optional) – HTTP request headers.
Initiates a download of the resource at
urlwithout navigating. Thewill-downloadevent ofsessionwill be triggered.contents.getURL()Returns
string– The URL of the current web page.const { BrowserWindow } = require('electron')
const win = new BrowserWindow({ width: 800, height: 600 })
win.loadURL('https://github.com').then(() => {
const currentURL = win.webContents.getURL()
console.log(currentURL)
})contents.getTitle()Returns
string– The title of the current web page.contents.isDestroyed()Returns
boolean– Whether the web page is destroyed.contents.close([opts])optsObject (optional)waitForBeforeUnloadboolean – if true, fire thebeforeunloadevent before closing the page. If the page prevents the unload, the WebContents will not be closed. Thewill-prevent-unloadwill be fired if the page requests prevention of unload.
Closes the page, as if the web content had called
window.close().If the page is successfully closed (i.e. the unload is not prevented by the page, or
waitForBeforeUnloadis false or unspecified), the WebContents will be destroyed and no longer usable. Thedestroyedevent will be emitted.contents.focus()Focuses the web page.
contents.isFocused()Returns
boolean– Whether the web page is focused.contents.isLoading()Returns
boolean– Whether web page is still loading resources.contents.isLoadingMainFrame()Returns
boolean– Whether the main frame (and not just iframes or frames within it) is still loading.contents.isWaitingForResponse()Returns
boolean– Whether the web page is waiting for a first-response from the main resource of the page.contents.stop()Stops any pending navigation.
contents.reload()Reloads the current web page.
contents.reloadIgnoringCache()Reloads current page and ignores cache.
contents.canGoBack()Returns
boolean– Whether the browser can go back to previous web page.contents.canGoForward()Returns
boolean– Whether the browser can go forward to next web page.contents.canGoToOffset(offset)offsetInteger
Returns
boolean– Whether the web page can go tooffset.contents.clearHistory()Clears the navigation history.
contents.goBack()Makes the browser go back a web page.
contents.goForward()Makes the browser go forward a web page.
contents.goToIndex(index)indexInteger
Navigates browser to the specified absolute web page index.
contents.goToOffset(offset)offsetInteger
Navigates to the specified offset from the “current entry”.
contents.isCrashed()Returns
boolean– Whether the renderer process has crashed.contents.forcefullyCrashRenderer()Forcefully terminates the renderer process that is currently hosting this
webContents. This will cause therender-process-goneevent to be emitted with thereason=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 theunresponsiveevent.const win = new BrowserWindow()
win.webContents.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) {
win.webContents.forcefullyCrashRenderer()
win.webContents.reload()
}
})contents.setUserAgent(userAgent)userAgentstring
Overrides the user agent for this web page.
contents.getUserAgent()Returns
string– The user agent for this web page.contents.insertCSS(css[, options])cssstringoptionsObject (optional)cssOriginstring (optional) – Can be ‘user’ or ‘author’. Sets the cascade origin of the inserted stylesheet. 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 viacontents.removeInsertedCSS(key).Injects CSS into the current web page and returns a unique key for the inserted stylesheet.
const win = new BrowserWindow()
win.webContents.on('did-finish-load', () => {
win.webContents.insertCSS('html, body { background-color: #f00; }')
})contents.removeInsertedCSS(key)keystring
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).const win = new BrowserWindow()
win.webContents.on('did-finish-load', async () => {
const key = await win.webContents.insertCSS('html, body { background-color: #f00; }')
win.webContents.removeInsertedCSS(key)
})contents.executeJavaScript(code[, userGesture])codestringuserGestureboolean (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
codein page.In the browser window some HTML APIs like
requestFullScreencan only be invoked by a gesture from the user. SettinguserGesturetotruewill remove this limitation.Code execution will be suspended until web page stop loading.
const win = new BrowserWindow()
win.webContents.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
})contents.executeJavaScriptInIsolatedWorld(worldId, scripts[, userGesture])worldIdInteger – The ID of the world to run the javascript in,0is the default world,999is the world used by Electron’scontextIsolationfeature. You can provide any integer here.scriptsWebSource[]userGestureboolean (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
executeJavaScriptbut evaluatesscriptsin an isolated context.contents.setIgnoreMenuShortcuts(ignore)ignoreboolean
Ignore application menu shortcuts while this web contents is focused.
contents.setWindowOpenHandler(handler)handlerFunction<WindowOpenHandlerResponse>detailsObjecturlstring – The resolved version of the URL passed towindow.open(). e.g. opening a window withwindow.open('foo')will yield something likehttps://the-origin/the/current/path/foo.frameNamestring – Name of the window provided inwindow.open()featuresstring – Comma separated list of window features provided towindow.open().dispositionstring – Can bedefault,foreground-tab,background-tab,new-windoworother.referrerReferrer – The referrer that will be passed to the new window. May or may not result in theRefererheader being sent, depending on the referrer policy.postBodyPostBody (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.
WindowOpenHandlerResponse– When set to{ action: 'deny' }cancels the creation of the new window.{ action: 'allow' }will allow the new window to be created. Returning an unrecognized value such as a null, undefined, or an object without a recognized ‘action’ value will result in a console error and have the same effect as returning{action: 'deny'}.
Called before creating a window a new window is requested by the renderer, e.g. by
window.open(), a link withtarget="_blank", shift+clicking on a link, or submitting a form with<form target="_blank">. Seewindow.open()for more details and how to use this in conjunction withdid-create-window.An example showing how to customize the process of new
BrowserWindowcreation to beBrowserViewattached to main window instead:const { BrowserView, BrowserWindow } = require('electron')
const mainWindow = new BrowserWindow()
mainWindow.webContents.setWindowOpenHandler((details) => {
return {
action: 'allow',
createWindow: (options) => {
const browserView = new BrowserView(options)
mainWindow.addBrowserView(browserView)
browserView.setBounds({ x: 0, y: 0, width: 640, height: 480 })
return browserView.webContents
}
}
})contents.setAudioMuted(muted)mutedboolean
Mute the audio on the current web page.
contents.isAudioMuted()Returns
boolean– Whether this page has been muted.contents.isCurrentlyAudible()Returns
boolean– Whether audio is currently playing.contents.setZoomFactor(factor)factorDouble – 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.
contents.getZoomFactor()Returns
number– the current zoom factor.contents.setZoomLevel(level)levelnumber – 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.NOTE: The zoom policy at the Chromium level is same-origin, meaning that the zoom level for a specific domain propagates across all instances of windows with the same domain. Differentiating the window URLs will make zoom work per-window.
contents.getZoomLevel()Returns
number– the current zoom level.contents.setVisualZoomLevelLimits(minimumLevel, maximumLevel)minimumLevelnumbermaximumLevelnumber
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:
const win = new BrowserWindow()
win.webContents.setVisualZoomLevelLimits(1, 3)contents.undo()Executes the editing command
undoin web page.contents.redo()Executes the editing command
redoin web page.contents.cut()Executes the editing command
cutin web page.contents.copy()Executes the editing command
copyin web page.contents.centerSelection()Centers the current text selection in web page.
contents.copyImageAt(x, y)xIntegeryInteger
Copy the image at the given position to the clipboard.
contents.paste()Executes the editing command
pastein web page.contents.pasteAndMatchStyle()Executes the editing command
pasteAndMatchStylein web page.contents.delete()Executes the editing command
deletein web page.contents.selectAll()Executes the editing command
selectAllin web page.contents.unselect()Executes the editing command
unselectin web page.contents.scrollToTop()Scrolls to the top of the current
webContents.contents.scrollToBottom()Scrolls to the bottom of the current
webContents.contents.adjustSelection(options)optionsObjectstartNumber (optional) – Amount to shift the start index of the current selection.endNumber (optional) – Amount to shift the end index of the current selection.
Adjusts the current text selection starting and ending points in the focused frame by the given amounts. A negative amount moves the selection towards the beginning of the document, and a positive amount moves the selection towards the end of the document.
Example:
const win = new BrowserWindow()
// Adjusts the beginning of the selection 1 letter forward,
// and the end of the selection 5 letters forward.
win.webContents.adjustSelection({ start: 1, end: 5 })
// Adjusts the beginning of the selection 2 letters forward,
// and the end of the selection 3 letters backward.
win.webContents.adjustSelection({ start: 2, end: -3 })For a call of
win.webContents.adjustSelection({ start: 1, end: 5 })Before:

After:

contents.replace(text)textstring
Executes the editing command
replacein web page.contents.replaceMisspelling(text)textstring
Executes the editing command
replaceMisspellingin web page.contents.insertText(text)textstring
Returns
Promise<void>Inserts
textto the focused element.contents.findInPage(text[, options])textstring – Content to be searched, must not be empty.optionsObject (optional)forwardboolean (optional) – Whether to search forward or backward, defaults totrue.findNextboolean (optional) – Whether to begin a new text finding session with this request. Should betruefor initial requests, andfalsefor follow-up requests. Defaults tofalse.matchCaseboolean (optional) – Whether search should be case-sensitive, defaults tofalse.
Returns
Integer– The request id used for the request.Starts a request to find all matches for the
textin the web page. The result of the request can be obtained by subscribing tofound-in-pageevent.contents.stopFindInPage(action)actionstring – Specifies the action to take place when endingwebContents.findInPagerequest.clearSelection– Clear the selection.keepSelection– Translate the selection into a normal selection.activateSelection– Focus and click the selection node.
Stops any
findInPagerequest for thewebContentswith the providedaction.const win = new BrowserWindow()
win.webContents.on('found-in-page', (event, result) => {
if (result.finalUpdate) win.webContents.stopFindInPage('clearSelection')
})
const requestId = win.webContents.findInPage('api')
console.log(requestId)contents.capturePage([rect, opts])rectRectangle (optional) – The area of the page to be captured.optsObject (optional)stayHiddenboolean (optional) – Keep the page hidden instead of visible. Default isfalse.stayAwakeboolean (optional) – Keep the system awake instead of allowing it to sleep. Default isfalse.
Returns
Promise<NativeImage>– Resolves with a NativeImageCaptures a snapshot of the page within
rect. Omittingrectwill capture the whole visible page. 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 thatstayHiddenis set to true.contents.isBeingCaptured()Returns
boolean– Whether this page is being captured. It returns true when the capturer count is large then 0.contents.getPrintersAsync()Get the system printer list.
Returns
Promise<PrinterInfo[]>– Resolves with a PrinterInfo[]contents.print([options], [callback])optionsObject (optional)silentboolean (optional) – Don’t ask user for print settings. Default isfalse.printBackgroundboolean (optional) – Prints the background color and image of the web page. Default isfalse.deviceNamestring (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’.colorboolean (optional) – Set whether the printed web page will be in color or grayscale. Default istrue.marginsObject (optional)marginTypestring (optional) – Can bedefault,none,printableArea, orcustom. Ifcustomis chosen, you will also need to specifytop,bottom,left, andright.topnumber (optional) – The top margin of the printed web page, in pixels.bottomnumber (optional) – The bottom margin of the printed web page, in pixels.leftnumber (optional) – The left margin of the printed web page, in pixels.rightnumber (optional) – The right margin of the printed web page, in pixels.
landscapeboolean (optional) – Whether the web page should be printed in landscape mode. Default isfalse.scaleFactornumber (optional) – The scale factor of the web page.pagesPerSheetnumber (optional) – The number of pages to print per page sheet.collateboolean (optional) – Whether the web page should be collated.copiesnumber (optional) – The number of copies of the web page to print.pageRangesObject[] (optional) – The page range to print. On macOS, only one range is honored.fromnumber – Index of the first page to print (0-based).tonumber – Index of the last page to print (inclusive) (0-based).
duplexModestring (optional) – Set the duplex mode of the printed web page. Can besimplex,shortEdge, orlongEdge.dpiRecord(optional) horizontalnumber (optional) – The horizontal dpi.verticalnumber (optional) – The vertical dpi.
headerstring (optional) – string to be printed as page header.footerstring (optional) – string to be printed as page footer.pageSizestring | Size (optional) – Specify page size of the printed document. Can beA0,A1,A2,A3,A4,A5,A6,Legal,Letter,Tabloidor an Object containingheightandwidth.
callbackFunction (optional)successboolean – Indicates success of the print call.failureReasonstring – Error description called back if the print fails.
When a custom
pageSizeis passed, Chromium attempts to validate platform specific minimum values forwidth_micronsandheight_microns. Width and height must both be minimum 353 microns but may be higher on some operating systems.Prints window’s web page. When
silentis set totrue, Electron will pick the system’s default printer ifdeviceNameis 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 win = new BrowserWindow()
const options = {
silent: true,
deviceName: 'My-Printer',
pageRanges: [{
from: 0,
to: 1
}]
}
win.webContents.print(options, (success, errorType) => {
if (!success) console.log(errorType)
})contents.printToPDF(options)optionsObjectlandscapeboolean (optional) – Paper orientation.truefor landscape,falsefor portrait. Defaults to false.displayHeaderFooterboolean (optional) – Whether to display header and footer. Defaults to false.printBackgroundboolean (optional) – Whether to print background graphics. Defaults to false.scalenumber(optional) – Scale of the webpage rendering. Defaults to 1.pageSizestring | Size (optional) – Specify page size of the generated PDF. Can beA0,A1,A2,A3,A4,A5,A6,Legal,Letter,Tabloid,Ledger, or an Object containingheightandwidthin inches. Defaults toLetter.marginsObject (optional)topnumber (optional) – Top margin in inches. Defaults to 1cm (~0.4 inches).bottomnumber (optional) – Bottom margin in inches. Defaults to 1cm (~0.4 inches).leftnumber (optional) – Left margin in inches. Defaults to 1cm (~0.4 inches).rightnumber (optional) – Right margin in inches. Defaults to 1cm (~0.4 inches).
pageRangesstring (optional) – Page ranges to print, e.g., ‘1-5, 8, 11-13’. Defaults to the empty string, which means print all pages.headerTemplatestring (optional) – HTML template for the print header. Should be valid HTML markup with following classes used to inject printing values into them:date(formatted print date),title(document title),url(document location),pageNumber(current page number) andtotalPages(total pages in the document). For example,<span class=title></span>would generate span containing the title.footerTemplatestring (optional) – HTML template for the print footer. Should use the same format as theheaderTemplate.preferCSSPageSizeboolean (optional) – Whether or not to prefer page size as defined by css. Defaults to false, in which case the content will be scaled to fit the paper size.generateTaggedPDFboolean (optional) Experimental – Whether or not to generate a tagged (accessible) PDF. Defaults to false. As this property is experimental, the generated PDF may not adhere fully to PDF/UA and WCAG standards.generateDocumentOutlineboolean (optional) Experimental – Whether or not to generate a PDF document outline from content headers. Defaults to false.
Returns
Promise<Buffer>– Resolves with the generated PDF data.Prints the window’s web page as PDF.
The
landscapewill be ignored if@pageCSS at-rule is used in the web page.An example of
webContents.printToPDF:const { app, BrowserWindow } = require('electron')
const fs = require('node:fs')
const path = require('node:path')
const os = require('node:os')
app.whenReady().then(() => {
const win = new BrowserWindow()
win.loadURL('https://github.com')
win.webContents.on('did-finish-load', () => {
// Use default printing options
const pdfPath = path.join(os.homedir(), 'Desktop', 'temp.pdf')
win.webContents.printToPDF({}).then(data => {
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)
})
})
})See Page.printToPdf for more information.
contents.addWorkSpace(path)pathstring
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)
})contents.removeWorkSpace(path)pathstring
Removes the specified path from DevTools workspace.
contents.setDevToolsWebContents(devToolsWebContents)devToolsWebContentsWebContents
Uses the
devToolsWebContentsas the targetWebContentsto show devtools.The
devToolsWebContentsmust 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
WebContentswith native view, which developers have very limited control of. With thesetDevToolsWebContentsmethod, developers can use anyWebContentsto show the devtools in it, includingBrowserWindow,BrowserViewand<webview>tag.Note that closing the devtools does not destroy the
devToolsWebContents, it is caller’s responsibility to destroydevToolsWebContents.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:main.js
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' })
})contents.openDevTools([options])optionsObject (optional)modestring – Opens the devtools with specified dock state, can beleft,right,bottom,undocked,detach. Defaults to last used dock state. Inundockedmode it’s possible to dock back. Indetachmode it’s not.activateboolean (optional) – Whether to bring the opened devtools window to the foreground. The default istrue.titlestring (optional) – A title for the DevTools window (only inundockedordetachmode).
Opens the devtools.
When
contentsis a<webview>tag, themodewould bedetachby default, explicitly passing an emptymodecan force using last used dock state.On Windows, if Windows Control Overlay is enabled, Devtools will be opened with
mode: 'detach'.contents.closeDevTools()Closes the devtools.
contents.isDevToolsOpened()Returns
boolean– Whether the devtools is opened.contents.isDevToolsFocused()Returns
boolean– Whether the devtools view is focused .contents.getDevToolsTitle()Returns
string– the current title of the DevTools window. This will only be visible if DevTools is opened inundockedordetachmode.contents.setDevToolsTitle(title)titlestring
Changes the title of the DevTools window to
title. This will only be visible if DevTools is opened inundockedordetachmode.contents.toggleDevTools()Toggles the developer tools.
contents.inspectElement(x, y)xIntegeryInteger
Starts inspecting element at position (
x,y).contents.inspectSharedWorker()Opens the developer tools for the shared worker context.
contents.inspectSharedWorkerById(workerId)workerIdstring
Inspects the shared worker based on its ID.
contents.getAllSharedWorkers()Returns SharedWorkerInfo[] – Information about all Shared Workers.
contents.inspectServiceWorker()Opens the developer tools for the service worker context.
contents.send(channel, ...args)channelstring...argsany[]
Send an asynchronous message to the renderer process via
channel, along with arguments. Arguments will be serialized with the Structured Clone Algorithm, just likepostMessage, so prototype chains will not be included. Sending Functions, Promises, Symbols, WeakMaps, or WeakSets will throw an exception.WARNING
Sending non-standard JavaScript types such as DOM objects or special Electron objects will throw an exception.
For additional reading, refer to Electron’s IPC guide.
contents.sendToFrame(frameId, channel, ...args)frameIdInteger | [number, number] – the ID of the frame to send to, or a pair of[processId, frameId]if the frame is in a different process to the main frame.channelstring...argsany[]
Send an asynchronous message to a specific frame in a renderer process via
channel, along with arguments. Arguments will be serialized with the Structured Clone Algorithm, just likepostMessage, 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
channelwith theipcRenderermodule.If you want to get the
frameIdof a given renderer context you should use thewebFrame.routingIdvalue. E.g.// In a renderer process
console.log('My frameId is:', require('electron').webFrame.routingId)You can also read
frameIdfrom all incoming IPC messages in the main process.// In the main process
ipcMain.on('ping', (event) => {
console.info('Message came from frameId:', event.frameId)
})contents.postMessage(channel, message, [transfer])channelstringmessageanytransferMessagePortMain[] (optional)
Send a message to the renderer process, optionally transferring ownership of zero or more
MessagePortMainobjects.The transferred
MessagePortMainobjects will be available in the renderer process by accessing theportsproperty of the emitted event. When they arrive in the renderer, they will be native DOMMessagePortobjects.For example:
// Main process
const win = new BrowserWindow()
const { port1, port2 } = new MessageChannelMain()
win.webContents.postMessage('port', { message: 'hello' }, [port1])
// Renderer process
ipcRenderer.on('port', (e, msg) => {
const [port] = e.ports
// ...
})contents.enableDeviceEmulation(parameters)parametersObjectscreenPositionstring – Specify the screen type to emulate (default:desktop):desktop– Desktop screen type.mobile– Mobile screen type.
screenSizeSize – Set the emulated screen size (screenPosition == mobile).viewPositionPoint – Position the view on the screen (screenPosition == mobile) (default:{ x: 0, y: 0 }).deviceScaleFactorInteger – Set the device scale factor (if zero defaults to original device scale factor) (default:0).viewSizeSize – Set the emulated view size (empty means no override)scaleFloat – Scale of emulated view inside available space (not in fit to view mode) (default:1).
Enable device emulation with the given parameters.
contents.disableDeviceEmulation()Disable device emulation enabled by
webContents.enableDeviceEmulation.contents.sendInputEvent(inputEvent)inputEventMouseInputEvent | MouseWheelInputEvent | KeyboardInputEvent
Sends an input
eventto the page. Note: TheBrowserWindowcontaining the contents needs to be focused forsendInputEvent()to work.contents.beginFrameSubscription([onlyDirty ,]callback)onlyDirtyboolean (optional) – Defaults tofalse.callbackFunctionimageNativeImagedirtyRectRectangle
Begin subscribing for presentation events and captured frames, the
callbackwill be called withcallback(image, dirtyRect)when there is a presentation event.The
imageis an instance of NativeImage that stores the captured frame.The
dirtyRectis an object withx, y, width, heightproperties that describes which part of the page was repainted. IfonlyDirtyis set totrue,imagewill only contain the repainted area.onlyDirtydefaults tofalse.contents.endFrameSubscription()End subscribing for frame presentation events.
contents.startDrag(item)itemObjectfilestring – The path to the file being dragged.filesstring[] (optional) – The paths to the files being dragged. (fileswill overridefilefield)iconNativeImage | string – The image must be non-empty on macOS.
Sets the
itemas dragging item for current drag-drop operation,fileis the absolute path of the file to be dragged, andiconis the image showing under the cursor when dragging.contents.savePage(fullPath, saveType)fullPathstring – The absolute file path.saveTypestring – Specify the save type.HTMLOnly– Save only the HTML of the page.HTMLComplete– Save complete-html page.MHTML– Save complete-html page as MHTML.
Returns
Promise<void>– resolves if the page is saved.const { BrowserWindow } = require('electron')
const win = new BrowserWindow()
win.loadURL('https://github.com')
win.webContents.on('did-finish-load', async () => {
win.webContents.savePage('/tmp/test.html', 'HTMLComplete').then(() => {
console.log('Page was saved successfully.')
}).catch(err => {
console.log(err)
})
})contents.showDefinitionForSelection()macOSShows pop-up dictionary that searches the selected word on the page.
contents.isOffscreen()Returns
boolean– Indicates whether offscreen rendering is enabled.contents.startPainting()If offscreen rendering is enabled and not painting, start painting.
contents.stopPainting()If offscreen rendering is enabled and painting, stop painting.
contents.isPainting()Returns
boolean– If offscreen rendering is enabled returns whether it is currently painting.contents.setFrameRate(fps)fpsInteger
If offscreen rendering is enabled sets the frame rate to the specified number. Only values between 1 and 240 are accepted.
contents.getFrameRate()Returns
Integer– If offscreen rendering is enabled returns the current frame rate.contents.invalidate()Schedules a full repaint of the window this web contents is in.
If offscreen rendering is enabled invalidates the frame and generates a new one through the
'paint'event.contents.getWebRTCIPHandlingPolicy()Returns
string– Returns the WebRTC IP Handling Policy.contents.setWebRTCIPHandlingPolicy(policy)policystring – Specify the WebRTC IP Handling Policy.default– Exposes user’s public and local IPs. This is the default behavior. When this policy is used, WebRTC has the right to enumerate all interfaces and bind them to discover public interfaces.default_public_interface_only– Exposes user’s public IP, but does not expose user’s local IP. When this policy is used, WebRTC should only use the default route used by http. This doesn’t expose any local addresses.default_public_and_private_interfaces– Exposes user’s public and local IPs. When this policy is used, WebRTC should only use the default route used by http. This also exposes the associated default private address. Default route is the route chosen by the OS on a multi-homed endpoint.disable_non_proxied_udp– Does not expose public or local IPs. When this policy is used, WebRTC should only use TCP to contact peers or servers unless the proxy server supports UDP.
Setting the WebRTC IP handling policy allows you to control which IPs are exposed via WebRTC. See BrowserLeaks for more details.
contents.getWebRTCUDPPortRange()Returns
Object:minInteger – The minimum UDP port number that WebRTC should use.maxInteger – The maximum UDP port number that WebRTC should use.
By default this value is
{ min: 0, max: 0 }, which would apply no restriction on the udp port range.contents.setWebRTCUDPPortRange(udpPortRange)udpPortRangeObjectminInteger – The minimum UDP port number that WebRTC should use.maxInteger – The maximum UDP port number that WebRTC should use.
Setting the WebRTC UDP Port Range allows you to restrict the udp port range used by WebRTC. By default the port range is unrestricted. Note: To reset to an unrestricted port range this value should be set to
{ min: 0, max: 0 }.contents.getMediaSourceId(requestWebContents)requestWebContentsWebContents – Web contents that the id will be registered to.
Returns
string– The identifier of a WebContents stream. This identifier can be used withnavigator.mediaDevices.getUserMediausing achromeMediaSourceoftab. The identifier is restricted to the web contents that it is registered to and is only valid for 10 seconds.contents.getOSProcessId()Returns
Integer– The operating systempidof the associated renderer process.contents.getProcessId()Returns
Integer– The Chromium internalpidof the associated renderer. Can be compared to theframeProcessIdpassed by frame specific navigation events (e.g.did-frame-navigate)contents.takeHeapSnapshot(filePath)filePathstring – Path to the output file.
Returns
Promise<void>– Indicates whether the snapshot has been created successfully.Takes a V8 heap snapshot and saves it to
filePath.contents.getBackgroundThrottling()Returns
boolean– whether or not this WebContents will throttle animations and timers when the page becomes backgrounded. This also affects the Page Visibility API.contents.setBackgroundThrottling(allowed)allowedboolean
Controls whether or not this WebContents will throttle animations and timers when the page becomes backgrounded. This also affects the Page Visibility API.
contents.getType()Returns
string– the type of the webContent. Can bebackgroundPage,window,browserView,remote,webvieworoffscreen.contents.setImageAnimationPolicy(policy)policystring – Can beanimate,animateOnceornoAnimation.
Sets the image animation policy for this webContents. The policy only affects new images, existing images that are currently being animated are unaffected. This is a known limitation in Chromium, you can force image animation to be recalculated with
img.src = img.srcwhich will result in no network traffic but will update the animation policy.This corresponds to the animationPolicy accessibility feature in Chromium.
Instance Properties
contents.ipcReadonlyAn
IpcMainscoped to just IPC messages sent from this WebContents.IPC messages sent with
ipcRenderer.send,ipcRenderer.sendSyncoripcRenderer.postMessagewill be delivered in the following order:contents.on('ipc-message')contents.mainFrame.on(channel)contents.ipc.on(channel)ipcMain.on(channel)
Handlers registered with
invokewill be checked in the following order. The first one that is defined will be called, the rest will be ignored.contents.mainFrame.handle(channel)contents.handle(channel)ipcMain.handle(channel)
A handler or event listener registered on the WebContents will receive IPC messages sent from any frame, including child frames. In most cases, only the main frame can send IPC messages. However, if the
nodeIntegrationInSubFramesoption is enabled, it is possible for child frames to send IPC messages also. In that case, handlers should check thesenderFrameproperty of the IPC event to ensure that the message is coming from the expected frame. Alternatively, register handlers on the appropriate frame directly using theWebFrameMain.ipcinterface.contents.audioMutedA
booleanproperty that determines whether this page is muted.contents.userAgentA
stringproperty that determines the user agent for this web page.contents.zoomLevelA
numberproperty that determines the zoom level for this web contents.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.contents.zoomFactorA
numberproperty that determines the zoom factor for this web contents.The zoom factor is the zoom percent divided by 100, so 300% = 3.0.
contents.frameRateAn
Integerproperty that sets the frame rate of the web contents to the specified number. Only values between 1 and 240 are accepted.Only applicable if offscreen rendering is enabled.
contents.idReadonlyA
Integerrepresenting the unique ID of this WebContents. Each ID is unique among allWebContentsinstances of the entire Electron application.contents.sessionReadonlyA
Sessionused by this webContents.contents.navigationHistoryReadonlyA
NavigationHistoryused by this webContents.contents.hostWebContentsReadonlyA
WebContentsinstance that might own thisWebContents.contents.devToolsWebContentsReadonlyA
WebContents | nullproperty that represents the of DevToolsWebContentsassociated with a givenWebContents.Note: Users should never store this object because it may become
nullwhen the DevTools has been closed.contents.debuggerReadonlyA
Debuggerinstance for this webContents.contents.backgroundThrottlingA
booleanproperty that determines whether or not this WebContents will throttle animations and timers when the page becomes backgrounded. This also affects the Page Visibility API.contents.mainFrameReadonlyA
WebFrameMainproperty that represents the top frame of the page’s frame hierarchy.contents.openerReadonlyA
WebFrameMainproperty that represents the frame that opened this WebContents, either with open(), or by navigating a link with a target attribute.