Merge pull request #5824 from electron/cleanup-web-contents

Cleanup the web-contents.js code

docs/api/web-contents.md

@@ -691,7 +691,8 @@ size.
   * `marginsType` Integer - Specifies the type of margins to use. Uses 0 for
     default margin, 1 for no margin, and 2 for minimum margin.
   * `pageSize` String - Specify page size of the generated PDF. Can be `A3`,
-    `A4`, `A5`, `Legal`, `Letter`, `Tabloid` or an Object containing `height` & `width` in Microns.
+    `A4`, `A5`, `Legal`, `Letter`, `Tabloid` or an Object containing `height`
+    and `width` in microns.
   * `printBackground` Boolean - Whether to print CSS backgrounds.
   * `printSelectionOnly` Boolean - Whether to print selection only.
   * `landscape` Boolean - `true` for landscape, `false` for portrait.
@@ -714,6 +715,8 @@ By default, an empty `options` will be regarded as:
 }
 ```
 
+An example of `webContents.printToPDF`:
+
 ```javascript
 const {BrowserWindow} = require('electron');
 const fs = require('fs');

lib/browser/api/app.js

@@ -1,6 +1,7 @@
 'use strict'
 
-const {deprecate, Menu, session} = require('electron')
+const electron = require('electron')
+const {deprecate, Menu} = electron
 const {EventEmitter} = require('events')
 
 const bindings = process.atomBinding('app')
@@ -49,7 +50,7 @@ app.allowNTLMCredentialsForAllDomains = function (allow) {
   if (!this.isReady()) {
     this.commandLine.appendSwitch('auth-server-whitelist', domains)
   } else {
-    session.defaultSession.allowNTLMCredentialsForDomains(domains)
+    electron.session.defaultSession.allowNTLMCredentialsForDomains(domains)
   }
 }
 

lib/browser/api/web-contents.js

@@ -1,18 +1,22 @@
 'use strict'
 
 const {EventEmitter} = require('events')
-const {ipcMain, Menu, NavigationController} = require('electron')
+const {ipcMain, session, Menu, NavigationController} = require('electron')
+
+// session is not used here, the purpose is to make sure session is initalized
+// before the webContents module.
+session
 
 const binding = process.atomBinding('web_contents')
 const debuggerBinding = process.atomBinding('debugger')
 
 let nextId = 0
-
-let getNextId = function () {
+const getNextId = function () {
   return ++nextId
 }
 
-let PDFPageSize = {
+// Stock page sizes
+const PDFPageSizes = {
   A5: {
     custom_display_name: 'A5',
     height_microns: 210000,
@@ -52,6 +56,31 @@ let PDFPageSize = {
   }
 }
 
+// Default printing setting
+const defaultPrintingSetting = {
+  pageRage: [],
+  mediaSize: {},
+  landscape: false,
+  color: 2,
+  headerFooterEnabled: false,
+  marginsType: 0,
+  isFirstRequest: false,
+  requestID: getNextId(),
+  previewModifiable: true,
+  printToPDF: true,
+  printWithCloudPrint: false,
+  printWithPrivet: false,
+  printWithExtension: false,
+  deviceName: 'Save as PDF',
+  generateDraftData: true,
+  fitToPageEnabled: false,
+  duplex: 0,
+  copies: 1,
+  collate: true,
+  shouldPrintBackgrounds: false,
+  shouldPrintSelectionOnly: false
+}
+
 // Following methods are mapped to webFrame.
 const webFrameMethods = [
   'insertText',
@@ -60,9 +89,9 @@ const webFrameMethods = [
   'setZoomLevelLimits'
 ]
 
-let wrapWebContents = function (webContents) {
+// Add JavaScript wrappers for WebContents class.
+const wrapWebContents = function (webContents) {
   // webContents is an EventEmitter.
-  var controller, method, name, ref1
   Object.setPrototypeOf(webContents, EventEmitter.prototype)
 
   // Every remote callback from renderer process would add a listenter to the
@@ -81,21 +110,18 @@ let wrapWebContents = function (webContents) {
   webContents.sendToAll = sendWrapper.bind(null, true)
 
   // The navigation controller.
-  controller = new NavigationController(webContents)
-  ref1 = NavigationController.prototype
-  for (name in ref1) {
-    method = ref1[name]
+  const controller = new NavigationController(webContents)
+  for (const name in NavigationController.prototype) {
+    const method = NavigationController.prototype[name]
     if (method instanceof Function) {
-      (function (name, method) {
-        webContents[name] = function () {
-          return method.apply(controller, arguments)
-        }
-      })(name, method)
+      webContents[name] = function () {
+        return method.apply(controller, arguments)
+      }
     }
   }
 
   // Mapping webFrame methods.
-  for (let method of webFrameMethods) {
+  for (const method of webFrameMethods) {
     webContents[method] = function (...args) {
       this.send('ELECTRON_INTERNAL_RENDERER_WEB_FRAME_METHOD', method, args)
     }
@@ -111,7 +137,7 @@ let wrapWebContents = function (webContents) {
   // Make sure webContents.executeJavaScript would run the code only when the
   // webContents has been loaded.
   webContents.executeJavaScript = function (code, hasUserGesture, callback) {
-    let requestId = getNextId()
+    const requestId = getNextId()
     if (typeof hasUserGesture === 'function') {
       callback = hasUserGesture
       hasUserGesture = false
@@ -127,18 +153,16 @@ let wrapWebContents = function (webContents) {
 
   // Dispatch IPC messages to the ipc module.
   webContents.on('ipc-message', function (event, [channel, ...args]) {
-    ipcMain.emit.apply(ipcMain, [channel, event].concat(args))
+    ipcMain.emit(channel, event, ...args)
   })
   webContents.on('ipc-message-sync', function (event, [channel, ...args]) {
     Object.defineProperty(event, 'returnValue', {
       set: function (value) {
         return event.sendReply(JSON.stringify(value))
       },
-      get: function () {
-        return undefined
-      }
+      get: function () {}
     })
-    return ipcMain.emit.apply(ipcMain, [channel, event].concat(args))
+    ipcMain.emit(channel, event, ...args)
   })
 
   // Handle context menu action request from pepper plugin.
@@ -160,30 +184,7 @@ let wrapWebContents = function (webContents) {
   })
 
   webContents.printToPDF = function (options, callback) {
-    var printingSetting
-    printingSetting = {
-      pageRage: [],
-      mediaSize: {},
-      landscape: false,
-      color: 2,
-      headerFooterEnabled: false,
-      marginsType: 0,
-      isFirstRequest: false,
-      requestID: getNextId(),
-      previewModifiable: true,
-      printToPDF: true,
-      printWithCloudPrint: false,
-      printWithPrivet: false,
-      printWithExtension: false,
-      deviceName: 'Save as PDF',
-      generateDraftData: true,
-      fitToPageEnabled: false,
-      duplex: 0,
-      copies: 1,
-      collate: true,
-      shouldPrintBackgrounds: false,
-      shouldPrintSelectionOnly: false
-    }
+    const printingSetting = Object.assign({}, defaultPrintingSetting)
     if (options.landscape) {
       printingSetting.landscape = options.landscape
     }
@@ -198,40 +199,40 @@ let wrapWebContents = function (webContents) {
     }
 
     if (options.pageSize) {
-      let height = 0
-      let width = 0
-      if (typeof options.pageSize === 'object') {
+      const pageSize = options.pageSize
+      if (typeof pageSize === 'object') {
+        if (!pageSize.height || !pageSize.width) {
+          return callback(new Error('Must define height and width for pageSize'))
+        }
         // Dimensions in Microns
         // 1 meter = 10^6 microns
-        height = options.pageSize.height ? options.pageSize.height : 0
-        width = options.pageSize.width ? options.pageSize.width : 0
-      }
-
-      if (height > 0 && width > 0) {
         printingSetting.mediaSize = {
-          height_microns: height,
           name: 'CUSTOM',
-          width_microns: width,
-          custom_display_name: 'Custom'
+          custom_display_name: 'Custom',
+          height_microns: pageSize.height,
+          width_microns: pageSize.width
         }
-      } else if (PDFPageSize[options.pageSize]) {
-        printingSetting.mediaSize = PDFPageSize[options.pageSize]
+      } else if (PDFPageSizes[pageSize]) {
+        printingSetting.mediaSize = PDFPageSizes[pageSize]
       } else {
-        printingSetting.mediaSize = PDFPageSize['A4']
+        return callback(new Error(`Does not support pageSize with ${pageSize}`))
       }
+    } else {
+      printingSetting.mediaSize = PDFPageSizes['A4']
     }
 
-    return this._printToPDF(printingSetting, callback)
+    this._printToPDF(printingSetting, callback)
   }
 }
 
-// Wrapper for native class.
-let wrapDebugger = function (webContentsDebugger) {
+binding._setWrapWebContents(wrapWebContents)
+
+// Add JavaScript wrappers for Debugger class.
+const wrapDebugger = function (webContentsDebugger) {
   // debugger is an EventEmitter.
   Object.setPrototypeOf(webContentsDebugger, EventEmitter.prototype)
 }
 
-binding._setWrapWebContents(wrapWebContents)
 debuggerBinding._setWrapDebugger(wrapDebugger)
 
 module.exports = {