feat: remove nativeWindowOpen option (#29405)

Co-authored-by: Cheng Zhao <zcbenz@gmail.com>
Co-authored-by: Milan Burda <milan.burda@gmail.com>

docs/README.md

@@ -106,7 +106,6 @@ These individual tutorials expand on topics discussed in the guide above.
 * [`File` Object](api/file-object.md)
 * [`<webview>` Tag](api/webview-tag.md)
 * [`window.open` Function](api/window-open.md)
-* [`BrowserWindowProxy` Object](api/browser-window-proxy.md)
 
 ### Modules for the Main Process:
 

docs/api/browser-window-proxy.md

@@ -1,54 +0,0 @@
-## Class: BrowserWindowProxy
-
-> Manipulate the child browser window
-
-Process: [Renderer](../glossary.md#renderer-process)<br />
-_This class is not exported from the `'electron'` module. It is only available as a return value of other methods in the Electron API._
-
-The `BrowserWindowProxy` object is returned from `window.open` and provides
-limited functionality with the child window.
-
-### Instance Methods
-
-The `BrowserWindowProxy` object has the following instance methods:
-
-#### `win.blur()`
-
-Removes focus from the child window.
-
-#### `win.close()`
-
-Forcefully closes the child window without calling its unload event.
-
-#### `win.eval(code)`
-
-* `code` string
-
-Evaluates the code in the child window.
-
-#### `win.focus()`
-
-Focuses the child window (brings the window to front).
-
-#### `win.print()`
-
-Invokes the print dialog on the child window.
-
-#### `win.postMessage(message, targetOrigin)`
-
-* `message` any
-* `targetOrigin` string
-
-Sends a message to the child window with the specified origin or `*` for no
-origin preference.
-
-In addition to these methods, the child window implements `window.opener` object
-with no properties and a single method.
-
-### Instance Properties
-
-The `BrowserWindowProxy` object has the following instance properties:
-
-#### `win.closed`
-
-A `boolean` that is set to true after the child window gets closed.

docs/api/browser-window.md

@@ -341,9 +341,6 @@ It creates a new `BrowserWindow` with native properties as set by the `options`.
       [Chrome Content Scripts][chrome-content-scripts].  You can access this
       context in the dev tools by selecting the 'Electron Isolated Context'
       entry in the combo box at the top of the Console tab.
-    * `nativeWindowOpen` boolean (optional) - Whether to use native
-      `window.open()`. Defaults to `true`. Child windows will always have node
-      integration disabled unless `nodeIntegrationInSubFrames` is true.
     * `webviewTag` boolean (optional) - Whether to enable the [`<webview>` tag](webview-tag.md).
       Defaults to `false`. **Note:** The
       `preload` script configured for the `<webview>` will have node integration

docs/api/structures/post-body.md

@@ -7,17 +7,3 @@
   the `enctype` attribute of the submitted HTML form.
 * `boundary` string (optional) - The boundary used to separate multiple parts of
   the message. Only valid when `contentType` is `multipart/form-data`.
-
-Note that keys starting with `--` are not currently supported. For example, this will errantly submit as `multipart/form-data` when `nativeWindowOpen` is set to `false` in webPreferences:
-
-```html
-<form
-  target="_blank"
-  method="POST"
-  enctype="application/x-www-form-urlencoded"
-  action="https://postman-echo.com/post"
->
-  <input type="text" name="--theKey">
-  <input type="submit">
-</form>
-```

docs/api/window-open.md

@@ -12,10 +12,6 @@ useful for app sub-windows that act as preference panels, or similar, as the
 parent can render to the sub-window directly, as if it were a `div` in the
 parent. This is the same behavior as in the browser.
 
-When `nativeWindowOpen` is set to false, `window.open` instead results in the
-creation of a [`BrowserWindowProxy`](browser-window-proxy.md), a light wrapper
-around `BrowserWindow`.
-
 Electron pairs this native Chrome `Window` with a BrowserWindow under the hood.
 You can take advantage of all the customization available when creating a
 BrowserWindow in the main process by using `webContents.setWindowOpenHandler()`
@@ -34,7 +30,7 @@ because it is invoked in the main process.
 * `frameName` string (optional)
 * `features` string (optional)
 
-Returns [`BrowserWindowProxy`](browser-window-proxy.md) | [`Window`](https://developer.mozilla.org/en-US/docs/Web/API/Window)
+Returns [`Window`](https://developer.mozilla.org/en-US/docs/Web/API/Window) | null
 
 `features` is a comma-separated key-value list, following the standard format of
 the browser. Electron will parse `BrowserWindowConstructorOptions` out of this
@@ -108,33 +104,3 @@ mainWindow.webContents.setWindowOpenHandler(({ url }) => {
 const childWindow = window.open('', 'modal')
 childWindow.document.write('<h1>Hello</h1>')
 ```
-
-### `BrowserWindowProxy` example
-
-```javascript
-
-// main.js
-const mainWindow = new BrowserWindow({
-  webPreferences: { nativeWindowOpen: false }
-})
-
-mainWindow.webContents.setWindowOpenHandler(({ url }) => {
-  if (url.startsWith('https://github.com/')) {
-    return { action: 'allow' }
-  }
-  return { action: 'deny' }
-})
-
-mainWindow.webContents.on('did-create-window', (childWindow) => {
-  // For example...
-  childWindow.webContents.on('will-navigate', (e) => {
-    e.preventDefault()
-  })
-})
-```
-
-```javascript
-// renderer.js
-const windowProxy = window.open('https://github.com/', null, 'minimizable=false')
-windowProxy.postMessage('hi', '*')
-```

docs/breaking-changes.md

@@ -12,6 +12,18 @@ This document uses the following convention to categorize breaking changes:
 * **Deprecated:** An API was marked as deprecated. The API will continue to function, but will emit a deprecation warning, and will be removed in a future release.
 * **Removed:** An API or feature was removed, and is no longer supported by Electron.
 
+## Planned Breaking API Changes (18.0)
+
+### Removed: `nativeWindowOpen`
+
+Prior to Electron 15, `window.open` was by default shimmed to use
+`BrowserWindowProxy`. This meant that `window.open('about:blank')` did not work
+to open synchronously scriptable child windows, among other incompatibilities.
+Since Electron 15, `nativeWindowOpen` has been enabled by default.
+
+See the documentation for [window.open in Electron](api/window-open.md)
+for more details.
+
 ## Planned Breaking API Changes (17.0)
 
 ### Removed: `desktopCapturer.getSources` in the renderer