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/Electron

`<webview>` Tag

Display external web content in an isolated frame and process.

Use the webview tag to embed 'guest' content (such as web pages) in your Electron app. The guest content is contained within the webview container. An embedded page within your app controls how the guest content is laid out and rendered.

Unlike an iframe, the webview runs in a separate process than your app. It doesn't have the same permissions as your web page and all interactions between your app and embedded content will be asynchronous. This keeps your app safe from the embedded content. Note: Most methods called on the webview from the host page require a synchronous call to the main process.

Example

To embed a web page in your app, add the webview tag to your app's embedder page (this is the app page that will display the guest content). In its simplest form, the webview tag includes the src of the web page and css styles that control the appearance of the webview container:

<webview id="foo" src="https://www.github.com/" style="display:inline-flex; width:640px; height:480px"></webview>

If you want to control the guest content in any way, you can write JavaScript that listens for webview events and responds to those events using the webview methods. Here's sample code with two event listeners: one that listens for the web page to start loading, the other for the web page to stop loading, and displays a "loading..." message during the load time:

<script>
    onload = () => {
      const webview = document.querySelector('webview')
      const indicator = document.querySelector('.indicator')
  
      const loadstart = () => {
        indicator.innerText = 'loading...'
      }
  
      const loadstop = () => {
        indicator.innerText = ''
      }
  
      webview.addEventListener('did-start-loading', loadstart)
      webview.addEventListener('did-stop-loading', loadstop)
    }
  </script>

CSS Styling Notes

Please note that the webview tag's style uses display:flex; internally to ensure the child object element fills the full height and width of its webview container when used with traditional and flexbox layouts (since v0.36.11). Please do not overwrite the default display:flex; CSS property, unless specifying display:inline-flex; for inline layout.

webview has issues being hidden using the hidden attribute or using display: none;. It can cause unusual rendering behaviour within its child browserplugin object and the web page is reloaded when the webview is un-hidden. The recommended approach is to hide the webview using visibility: hidden.

<style>
    webview {
      display:inline-flex;
      width:640px;
      height:480px;
    }
    webview.hide {
      visibility: hidden;
    }
  </style>

Tag Attributes

The webview tag has the following attributes:

`src`

<webview src="https://www.github.com/"></webview>

Returns the visible URL. Writing to this attribute initiates top-level navigation.

Assigning src its own value will reload the current page.

The src attribute can also accept data URLs, such as data:text/plain,Hello, world!.

`autosize`

<webview src="https://www.github.com/" autosize minwidth="576" minheight="432"></webview>

When this attribute is present the webview container will automatically resize within the bounds specified by the attributes minwidth, minheight, maxwidth, and maxheight. These constraints do not impact the webview unless autosize is enabled. When autosize is enabled, the webview container size cannot be less than the minimum values or greater than the maximum.

`nodeintegration`

<webview src="http://www.google.com/" nodeintegration></webview>

When this attribute is present the guest page in webview will have node integration and can use node APIs like require and process to access low level system resources. Node integration is disabled by default in the guest page.

`plugins`

<webview src="https://www.github.com/" plugins></webview>

When this attribute is present the guest page in webview will be able to use browser plugins. Plugins are disabled by default.

`preload`

<webview src="https://www.github.com/" preload="./test.js"></webview>

Specifies a script that will be loaded before other scripts run in the guest page. The protocol of script's URL must be either file: or asar:, because it will be loaded by require in guest page under the hood.

When the guest page doesn't have node integration this script will still have access to all Node APIs, but global objects injected by Node will be deleted after this script has finished executing.

Note: This option will be appear as preloadURL (not preload) in the webPreferences specified to the will-attach-webview event.

`httpreferrer`

<webview src="https://www.github.com/" httpreferrer="http://cheng.guru"></webview>

Sets the referrer URL for the guest page.

`useragent`

<webview src="https://www.github.com/" useragent="Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; AS; rv:11.0) like Gecko"></webview>

Sets the user agent for the guest page before the page is navigated to. Once the page is loaded, use the setUserAgent method to change the user agent.

`disablewebsecurity`

<webview src="https://www.github.com/" disablewebsecurity></webview>

When this attribute is present the guest page will have web security disabled. Web security is enabled by default.

`partition`

<webview src="https://github.com" partition="persist:github"></webview>
  <webview src="https://electronjs.org" partition="electron"></webview>

Sets the session used by the page. If partition starts with persist:, the page will use a persistent session available to all pages in the app with the same partition. if there is no persist: prefix, the page will use an in-memory session. By assigning the same partition, multiple pages can share the same session. If the partition is unset then default session of the app will be used.

This value can only be modified before the first navigation, since the session of an active renderer process cannot change. Subsequent attempts to modify the value will fail with a DOM exception.

`allowpopups`

<webview src="https://www.github.com/" allowpopups></webview>

When this attribute is present the guest page will be allowed to open new windows. Popups are disabled by default.

`webpreferences`

<webview src="https://github.com" webpreferences="allowRunningInsecureContent, javascript=no"></webview>

A list of strings which specifies the web preferences to be set on the webview, separated by ,. The full list of supported preference strings can be found in BrowserWindow.

The string follows the same format as the features string in window.open. A name by itself is given a true boolean value. A preference can be set to another value by including an =, followed by the value. Special values yes and 1 are interpreted as true, while no and 0 are interpreted as false.

`blinkfeatures`

<webview src="https://www.github.com/" blinkfeatures="PreciseMemoryInfo, CSSVariables"></webview>

A list of strings which specifies the blink features to be enabled separated by ,. The full list of supported feature strings can be found in the RuntimeEnabledFeatures.json5 file.

`disableblinkfeatures`

<webview src="https://www.github.com/" disableblinkfeatures="PreciseMemoryInfo, CSSVariables"></webview>

A list of strings which specifies the blink features to be disabled separated by ,. The full list of supported feature strings can be found in the RuntimeEnabledFeatures.json5 file.

`guestinstance`

<webview src="https://www.github.com/" guestinstance="3"></webview>

A value that links the webview to a specific webContents. When a webview first loads a new webContents is created and this attribute is set to its instance identifier. Setting this attribute on a new or existing webview connects it to the existing webContents that currently renders in a different webview.

The existing webview will see the destroy event and will then create a new webContents when a new url is loaded.

`disableguestresize`

<webview src="https://www.github.com/" disableguestresize></webview>

When this attribute is present the webview contents will be prevented from resizing when the webview element itself is resized.

This can be used in combination with webContents.setSize to manually resize the webview contents in reaction to a window size change. This can make resizing faster compared to relying on the webview element bounds to automatically resize the contents.

const {webContents} = require('electron')
  
  // We assume that `win` points to a `BrowserWindow` instance containing a
  // `<webview>` with `disableguestresize`.
  
  win.on('resize', () => {
    const [width, height] = win.getContentSize()
    for (let wc of webContents.getAllWebContents()) {
      // Check if `wc` belongs to a webview in the `win` window.
      if (wc.hostWebContents &&
          wc.hostWebContents.id === win.webContents.id) {
        wc.setSize({
          normal: {
            width: width,
            height: height
          }
        })
      }
    }
  })

Methods

The webview tag has the following methods:

Note: The webview element must be loaded before using the methods.

Example

const webview = document.querySelector('webview')
  webview.addEventListener('dom-ready', () => {
    webview.openDevTools()
  })

`<webview>.loadURL(url[, options])`

url URL
options Object (optional)
- httpReferrer String (optional) - A HTTP Referrer url.
- userAgent String (optional) - A user agent originating the request.
- extraHeaders String (optional) - Extra headers separated by "\n"
- postData (UploadRawData[] | UploadFile[] | UploadFileSystem[] | 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 specified url is a data url and needs to load other files.

Loads the url in the webview, the url must contain the protocol prefix, e.g. the http:// or file://.

`<webview>.getURL()`

Returns String - The URL of guest page.

`<webview>.getTitle()`

Returns String - The title of guest page.

`<webview>.isLoading()`

Returns Boolean - Whether guest page is still loading resources.

`<webview>.isWaitingForResponse()`

Returns Boolean - Whether the guest page is waiting for a first-response for the main resource of the page.

`<webview>.stop()`

Stops any pending navigation.

`<webview>.reload()`

Reloads the guest page.

`<webview>.reloadIgnoringCache()`

Reloads the guest page and ignores cache.

`<webview>.canGoBack()`

Returns Boolean - Whether the guest page can go back.

`<webview>.canGoForward()`

Returns Boolean - Whether the guest page can go forward.

`<webview>.canGoToOffset(offset)`

offset Integer

Returns Boolean - Whether the guest page can go to offset.

`<webview>.clearHistory()`

Clears the navigation history.

`<webview>.goBack()`

Makes the guest page go back.

`<webview>.goForward()`

Makes the guest page go forward.

`<webview>.goToIndex(index)`

index Integer

Navigates to the specified absolute index.

`<webview>.goToOffset(offset)`

offset Integer

Navigates to the specified offset from the "current entry".

`<webview>.isCrashed()`

Returns Boolean - Whether the renderer process has crashed.

`<webview>.setUserAgent(userAgent)`

userAgent String

Overrides the user agent for the guest page.

`<webview>.getUserAgent()`

Returns String - The user agent for guest page.

`<webview>.insertCSS(css)`

css String

Injects CSS into the guest page.

`<webview>.executeJavaScript(code[, userGesture, callback])`

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

Evaluates code in page. If userGesture is set, it will create the user gesture context in the page. HTML APIs like requestFullScreen, which require user action, can take advantage of this option for automation.

`<webview>.openDevTools()`

Opens a DevTools window for guest page.

`<webview>.closeDevTools()`

Closes the DevTools window of guest page.

`<webview>.isDevToolsOpened()`

Returns Boolean - Whether guest page has a DevTools window attached.

`<webview>.isDevToolsFocused()`

Returns Boolean - Whether DevTools window of guest page is focused.

`<webview>.inspectElement(x, y)`

x Integer
y Integer

Starts inspecting element at position (x, y) of guest page.

`<webview>.inspectServiceWorker()`

Opens the DevTools for the service worker context present in the guest page.

`<webview>.setAudioMuted(muted)`

muted Boolean

Set guest page muted.

`<webview>.isAudioMuted()`

Returns Boolean - Whether guest page has been muted.

`<webview>.undo()`

Executes editing command undo in page.

`<webview>.redo()`

Executes editing command redo in page.

`<webview>.cut()`

Executes editing command cut in page.

`<webview>.copy()`

Executes editing command copy in page.

`<webview>.paste()`

Executes editing command paste in page.

`<webview>.pasteAndMatchStyle()`

Executes editing command pasteAndMatchStyle in page.

`<webview>.delete()`

Executes editing command delete in page.

`<webview>.selectAll()`

Executes editing command selectAll in page.

`<webview>.unselect()`

Executes editing command unselect in page.

`<webview>.replace(text)`

text String

Executes editing command replace in page.

`<webview>.replaceMisspelling(text)`

text String

Executes editing command replaceMisspelling in page.

`<webview>.insertText(text)`

text String

Inserts text to the focused element.

`<webview>.findInPage(text[, options])`

text String - Content to be searched, must not be empty.
options Object (optional)
- forward Boolean (optional) - Whether to search forward or backward, defaults to true.
- findNext Boolean (optional) - Whether the operation is first request or a follow up, defaults to false.
- matchCase Boolean (optional) - Whether search should be case-sensitive, defaults to false.
- wordStart Boolean (optional) - Whether to look only at the start of words. defaults to false.
- medialCapitalAsWordStart Boolean (optional) - When combined with wordStart, 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 to false.

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.

`<webview>.stopFindInPage(action)`

action String - Specifies the action to take place when ending <webview>.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 webview with the provided action.

`<webview>.print([options])`

options Object (optional)
- silent Boolean (optional) - Don't ask user for print settings. Default is false.
- printBackground Boolean (optional) - Also prints the background color and image of the web page. Default is false.
- deviceName String (optional) - Set the printer device name to use. Default is ''.

Prints webview's web page. Same as webContents.print([options]).

`<webview>.printToPDF(options, callback)`

options Object
- marginsType Integer (optional) - Specifies the type of margins to use. Uses 0 for default margin, 1 for no margin, and 2 for minimum margin.
- pageSize String (optional) - Specify page size of the generated PDF. Can be A3, A4, A5, Legal, Letter, Tabloid or an Object containing height and width in microns.
- printBackground Boolean (optional) - Whether to print CSS backgrounds.
- printSelectionOnly Boolean (optional) - Whether to print selection only.
- landscape Boolean (optional) - true for landscape, false for portrait.
callback Function
- error Error
- data Buffer

Prints webview's web page as PDF, Same as webContents.printToPDF(options, callback).

`<webview>.capturePage([rect, ]callback)`

rect Rectangle (optional) - The area of the page to be captured.
callback Function
- image NativeImage

Captures a snapshot of the webview's page. Same as webContents.capturePage([rect, ]callback).

`<webview>.send(channel[, arg1][, arg2][, ...])`

channel String
...args any[]

Send an asynchronous message to renderer process via channel, you can also send arbitrary arguments. The renderer process can handle the message by listening to the channel event with the ipcRenderer module.

See webContents.send for examples.

`<webview>.sendInputEvent(event)`

event Object

Sends an input event to the page.

See webContents.sendInputEvent for detailed description of event object.

`<webview>.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.

`<webview>.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.

`<webview>.showDefinitionForSelection()` macOS

Shows pop-up dictionary that searches the selected word on the page.

`<webview>.getWebContents()`

Returns WebContents - The web contents associated with this webview.

DOM events

The following DOM events are available to the webview tag:

Event: 'load-commit'

Returns:

url String
isMainFrame Boolean

Fired when a load has committed. This includes navigation within the current document as well as subframe document-level loads, but does not include asynchronous resource loads.

Event: 'did-finish-load'

Fired when the navigation is done, i.e. the spinner of the tab will stop spinning, and the onload event is dispatched.

Event: 'did-fail-load'

Returns:

errorCode Integer
errorDescription String
validatedURL String
isMainFrame Boolean

This event is like did-finish-load, but fired when the load failed or was cancelled, e.g. window.stop() is invoked.

Event: 'did-frame-finish-load'

Returns:

isMainFrame Boolean

Fired when a frame has done navigation.

Event: 'did-start-loading'

Corresponds to the points in time when the spinner of the tab starts spinning.

Event: 'did-stop-loading'

Corresponds to the points in time when the spinner of the tab stops spinning.

Event: 'did-get-response-details'

Returns:

status Boolean
newURL String
originalURL String
httpResponseCode Integer
requestMethod String
referrer String
headers Object
resourceType String

Fired when details regarding a requested resource is available. status indicates socket connection to download the resource.

Event: 'did-get-redirect-request'

Returns:

oldURL String
newURL String
isMainFrame Boolean

Fired when a redirect was received while requesting a resource.

Event: 'dom-ready'

Fired when document in the given frame is loaded.

Event: 'page-title-updated'

Returns:

title String
explicitSet Boolean

Fired when page title is set during navigation. explicitSet is false when title is synthesized from file url.

Event: 'page-favicon-updated'

Returns:

favicons String[] - Array of URLs.

Fired when page receives favicon urls.

Event: 'enter-html-full-screen'

Fired when page enters fullscreen triggered by HTML API.

Event: 'leave-html-full-screen'

Fired when page leaves fullscreen triggered by HTML API.

Event: 'console-message'

Returns:

level Integer
message String
line Integer
sourceId String

Fired when the guest window logs a console message.

The following example code forwards all log messages to the embedder's console without regard for log level or other properties.

const webview = document.querySelector('webview')
  webview.addEventListener('console-message', (e) => {
    console.log('Guest page logged a message:', e.message)
  })

Event: 'found-in-page'

Returns:

result Object
- requestId Integer
- activeMatchOrdinal Integer - Position of the active match.
- matches Integer - Number of Matches.
- selectionArea Object - Coordinates of first match region.
- finalUpdate Boolean

Fired when a result is available for webview.findInPage request.

const webview = document.querySelector('webview')
  webview.addEventListener('found-in-page', (e) => {
    webview.stopFindInPage('keepSelection')
  })
  
  const requestId = webview.findInPage('test')
  console.log(requestId)

Event: 'new-window'

Returns:

url String
frameName String
disposition String - Can be default, foreground-tab, background-tab, new-window, save-to-disk and other.
options Object - The options which should be used for creating the new BrowserWindow.

Fired when the guest page attempts to open a new browser window.

The following example code opens the new url in system's default browser.

const {shell} = require('electron')
  const webview = document.querySelector('webview')
  
  webview.addEventListener('new-window', (e) => {
    const protocol = require('url').parse(e.url).protocol
    if (protocol === 'http:' || protocol === 'https:') {
      shell.openExternal(e.url)
    }
  })

Event: 'will-navigate'

Returns:

url 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 <webview>.loadURL and <webview>.back.

It is also not emitted during in-page navigation, such as clicking anchor links or updating the window.location.hash. Use did-navigate-in-page event for this purpose.

Calling event.preventDefault() does NOT have any effect.

Event: 'did-navigate'

Returns:

url String

Emitted when a 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.

Event: 'did-navigate-in-page'

Returns:

isMainFrame Boolean
url String

Emitted when an in-page navigation happened.

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.

Event: 'close'

Fired when the guest page attempts to close itself.

The following example code navigates the webview to about:blank when the guest attempts to close itself.

const webview = document.querySelector('webview')
  webview.addEventListener('close', () => {
    webview.src = 'about:blank'
  })

Event: 'ipc-message'

Returns:

channel String
args Array

Fired when the guest page has sent an asynchronous message to embedder page.

With sendToHost method and ipc-message event you can easily communicate between guest page and embedder page:

// In embedder page.
  const webview = document.querySelector('webview')
  webview.addEventListener('ipc-message', (event) => {
    console.log(event.channel)
    // Prints "pong"
  })
  webview.send('ping')

// In guest page.
  const {ipcRenderer} = require('electron')
  ipcRenderer.on('ping', () => {
    ipcRenderer.sendToHost('pong')
  })

Event: 'crashed'

Fired when the renderer process is crashed.

Event: 'gpu-crashed'

Fired when the gpu process is crashed.

Event: 'plugin-crashed'

Returns:

name String
version String

Fired when a plugin process is crashed.

Event: 'destroyed'

Fired when the WebContents is destroyed.

Event: 'media-started-playing'

Emitted when media starts playing.

Event: 'media-paused'

Emitted when media is paused or done playing.

Event: 'did-change-theme-color'

Returns:

themeColor String

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:

url String

Emitted when mouse moves over a link or the keyboard moves the focus to a link.

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.

<webview> Tag

Example

CSS Styling Notes

Tag Attributes

src

autosize

nodeintegration

plugins

preload

httpreferrer

useragent

disablewebsecurity

partition

allowpopups

webpreferences

blinkfeatures

disableblinkfeatures

guestinstance

disableguestresize

Methods

<webview>.loadURL(url[, options])

<webview>.getURL()

<webview>.getTitle()

<webview>.isLoading()

<webview>.isWaitingForResponse()

<webview>.stop()

<webview>.reload()

<webview>.reloadIgnoringCache()

<webview>.canGoBack()

<webview>.canGoForward()

<webview>.canGoToOffset(offset)

<webview>.clearHistory()

<webview>.goBack()

<webview>.goForward()

<webview>.goToIndex(index)

<webview>.goToOffset(offset)

<webview>.isCrashed()

<webview>.setUserAgent(userAgent)

<webview>.getUserAgent()

<webview>.insertCSS(css)

<webview>.executeJavaScript(code[, userGesture, callback])

<webview>.openDevTools()

<webview>.closeDevTools()

<webview>.isDevToolsOpened()

<webview>.isDevToolsFocused()

<webview>.inspectElement(x, y)

<webview>.inspectServiceWorker()

<webview>.setAudioMuted(muted)

<webview>.isAudioMuted()

<webview>.undo()

<webview>.redo()

<webview>.cut()

<webview>.copy()

<webview>.paste()

<webview>.pasteAndMatchStyle()

<webview>.delete()

<webview>.selectAll()

<webview>.unselect()

<webview>.replace(text)

<webview>.replaceMisspelling(text)

<webview>.insertText(text)

<webview>.findInPage(text[, options])

<webview>.stopFindInPage(action)

<webview>.print([options])

<webview>.printToPDF(options, callback)

<webview>.capturePage([rect, ]callback)

<webview>.send(channel[, arg1][, arg2][, ...])

<webview>.sendInputEvent(event)

<webview>.setZoomFactor(factor)

<webview>.setZoomLevel(level)

<webview>.showDefinitionForSelection() macOS

<webview>.getWebContents()

DOM events

Event: 'load-commit'

Event: 'did-finish-load'

Event: 'did-fail-load'

Event: 'did-frame-finish-load'

Event: 'did-start-loading'

Event: 'did-stop-loading'

Event: 'did-get-response-details'

`<webview>` Tag

`src`

`autosize`

`nodeintegration`

`plugins`

`preload`

`httpreferrer`

`useragent`

`disablewebsecurity`

`partition`

`allowpopups`

`webpreferences`

`blinkfeatures`

`disableblinkfeatures`

`guestinstance`

`disableguestresize`

`<webview>.loadURL(url[, options])`

`<webview>.getURL()`

`<webview>.getTitle()`

`<webview>.isLoading()`

`<webview>.isWaitingForResponse()`

`<webview>.stop()`

`<webview>.reload()`

`<webview>.reloadIgnoringCache()`

`<webview>.canGoBack()`

`<webview>.canGoForward()`

`<webview>.canGoToOffset(offset)`

`<webview>.clearHistory()`

`<webview>.goBack()`

`<webview>.goForward()`

`<webview>.goToIndex(index)`

`<webview>.goToOffset(offset)`

`<webview>.isCrashed()`

`<webview>.setUserAgent(userAgent)`

`<webview>.getUserAgent()`

`<webview>.insertCSS(css)`

`<webview>.executeJavaScript(code[, userGesture, callback])`

`<webview>.openDevTools()`

`<webview>.closeDevTools()`

`<webview>.isDevToolsOpened()`

`<webview>.isDevToolsFocused()`

`<webview>.inspectElement(x, y)`

`<webview>.inspectServiceWorker()`

`<webview>.setAudioMuted(muted)`

`<webview>.isAudioMuted()`

`<webview>.undo()`

`<webview>.redo()`

`<webview>.cut()`

`<webview>.copy()`

`<webview>.paste()`

`<webview>.pasteAndMatchStyle()`

`<webview>.delete()`

`<webview>.selectAll()`

`<webview>.unselect()`

`<webview>.replace(text)`

`<webview>.replaceMisspelling(text)`

`<webview>.insertText(text)`

`<webview>.findInPage(text[, options])`

`<webview>.stopFindInPage(action)`

`<webview>.print([options])`

`<webview>.printToPDF(options, callback)`

`<webview>.capturePage([rect, ]callback)`

`<webview>.send(channel[, arg1][, arg2][, ...])`

`<webview>.sendInputEvent(event)`

`<webview>.setZoomFactor(factor)`

`<webview>.setZoomLevel(level)`

`<webview>.showDefinitionForSelection()` macOS

`<webview>.getWebContents()`