electron/docs/api/web-frame.md

webFrame

Customize the rendering of the current web page.

Process: Renderer

webFrame export of the electron module is an instance of the WebFrame class representing the top frame of the current BrowserWindow. Sub-frames can be retrieved by certain properties and methods (e.g. webFrame.firstChild).

An example of zooming current page to 200%.

const {webFrame} = require('electron')

webFrame.setZoomFactor(2)

Methods

The WebFrame class has the following instance methods:

webFrame.setZoomFactor(factor)

• factor Number - Zoom factor.

Changes the zoom factor to the specified factor. Zoom factor is zoom percent divided by 100, so 300% = 3.0.

webFrame.getZoomFactor()

Returns Number - The current zoom factor.

webFrame.setZoomLevel(level)

• 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.

webFrame.getZoomLevel()

Returns Number - The current zoom level.

webFrame.setVisualZoomLevelLimits(minimumLevel, maximumLevel)

• minimumLevel Number
• maximumLevel Number

Sets the maximum and minimum pinch-to-zoom level.

webFrame.setLayoutZoomLevelLimits(minimumLevel, maximumLevel)

• minimumLevel Number
• maximumLevel Number

Sets the maximum and minimum layout-based (i.e. non-visual) zoom level.

webFrame.setSpellCheckProvider(language, autoCorrectWord, provider)

• language String
• autoCorrectWord Boolean
• provider Object
  • spellCheck Function - Returns Boolean.
  • text String

Sets a provider for spell checking in input fields and text areas.

The provider must be an object that has a spellCheck method that returns whether the word passed is correctly spelled.

An example of using node-spellchecker as provider:

const {webFrame} = require('electron')
webFrame.setSpellCheckProvider('en-US', true, {
  spellCheck (text) {
    return !(require('spellchecker').isMisspelled(text))
  }
})

webFrame.registerURLSchemeAsBypassingCSP(scheme)

• scheme String

Resources will be loaded from this scheme regardless of the current page's Content Security Policy.

webFrame.registerURLSchemeAsPrivileged(scheme[, options])

• scheme String
• options Object (optional)
  • secure Boolean (optional) - Default true.
  • bypassCSP Boolean (optional) - Default true.
  • allowServiceWorkers Boolean (optional) - Default true.
  • supportFetchAPI Boolean (optional) - Default true.
  • corsEnabled Boolean (optional) - Default true.

Registers the scheme as secure, bypasses content security policy for resources, allows registering ServiceWorker and supports fetch API.

Specify an option with the value of false to omit it from the registration. An example of registering a privileged scheme, without bypassing Content Security Policy:

const {webFrame} = require('electron')
webFrame.registerURLSchemeAsPrivileged('foo', { bypassCSP: false })

webFrame.insertText(text)

• text String

Inserts text to the focused element.

webFrame.executeJavaScript(code[, userGesture, callback])

• code String
• userGesture Boolean (optional) - Default is false.
• callback Function (optional) - Called after script has been executed.
  • result Any

Returns Promise - 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.

webFrame.executeJavaScriptInIsolatedWorld(worldId, scripts[, userGesture, callback])

• worldId Integer
• scripts WebSource[]
• userGesture Boolean (optional) - Default is false.
• callback Function (optional) - Called after script has been executed.
  • result Any

Work like executeJavaScript but evaluates scripts in isolated context.

webFrame.setIsolatedWorldContentSecurityPolicy(worldId, csp)

• worldId Integer
• csp String

Set the content security policy of the isolated world.

webFrame.setIsolatedWorldHumanReadableName(worldId, name)

• worldId Integer
• name String

Set the name of the isolated world. Useful in devtools.

webFrame.setIsolatedWorldSecurityOrigin(worldId, securityOrigin)

• worldId Integer
• securityOrigin String

Set the security origin of the isolated world.

webFrame.getResourceUsage()

Returns Object:

• images MemoryUsageDetails
• cssStyleSheets MemoryUsageDetails
• xslStyleSheets MemoryUsageDetails
• fonts MemoryUsageDetails
• other MemoryUsageDetails

Returns an object describing usage information of Blink's internal memory caches.

const {webFrame} = require('electron')
console.log(webFrame.getResourceUsage())

This will generate:

{
  images: {
    count: 22,
    size: 2549,
    liveSize: 2542
  },
  cssStyleSheets: { /* same with "images" */ },
  xslStyleSheets: { /* same with "images" */ },
  fonts: { /* same with "images" */ },
  other: { /* same with "images" */ }
}

webFrame.clearCache()

Attempts to free memory that is no longer being used (like images from a previous navigation).

Note that blindly calling this method probably makes Electron slower since it will have to refill these emptied caches, you should only call it if an event in your app has occurred that makes you think your page is actually using less memory (i.e. you have navigated from a super heavy page to a mostly empty one, and intend to stay there).

webFrame.getFrameForSelector(selector)

• selector String - CSS selector for a frame element.

Returns WebFrame - The frame element in webFrame's document selected by selector, null would be returned if selector does not select a frame or if the frame is not in the current renderer process.

webFrame.findFrameByName(name)

• name String

Returns WebFrame - A child of webFrame with the supplied name, null would be returned if there's no such frame or if the frame is not in the current renderer process.

webFrame.findFrameByRoutingId(routingId)

• routingId Integer - An Integer representing the unique frame id in the current renderer process. Routing IDs can be retrieved from WebFrame instances (webFrame.routingId) and are also passed by frame specific WebContents navigation events (e.g. did-frame-navigate)
  

Returns WebFrame - that has the supplied routingId, null if not found.

Properties

webFrame.top

A WebFrame representing top frame in frame hierarchy to which webFrame belongs, the property would be null if top frame is not in the current renderer process.

webFrame.opener

A WebFrame representing the frame which opened webFrame, the property would be null if there's no opener or opener is not in the current renderer process.

webFrame.parent

A WebFrame representing parent frame of webFrame, the property would be null if webFrame is top or parent is not in the current renderer process.

webFrame.firstChild

A WebFrame representing the first child frame of webFrame, the property would be null if webFrame has no children or if first child is not in the current renderer process.

webFrame.nextSibling

A WebFrame representing next sibling frame, the property would be null if webFrame is the last frame in its parent or if the next sibling is not in the current renderer process.

webFrame.routingId

An Integer representing the unique frame id in the current renderer process. Distinct WebFrame instances that refer to the same underlying frame will have the same routingId.