[i18n] use Polymer data binding to change locale strings

chrome/browser/resources/chromeos/login/oobe_welcome.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview Polymer element for displaying material design OOBE.
  */
 
 Polymer({
   is: 'oobe-welcome-md',
@@ skipping 14 matching lines @@
       type: String,
       value: '',
     },
 
     /**
      * List of languages for language selector dropdown.
      * @type {!Array<OobeTypes.LanguageDsc>}
      */
     languages: {
       type: Array,
-      observer: "onLanguagesChanged_",
+      observer: 'onLanguagesChanged_',
     },
 
     /**
      * List of keyboards for keyboard selector dropdown.
      * @type {!Array<OobeTypes.IMEDsc>}
      */
     keyboards: {
       type: Array,
-      observer: "onKeyboardsChanged_",
+      observer: 'onKeyboardsChanged_',
     },
 
     /**
      * Flag that enables MD-OOBE.
      */
     enabled: {
       type: Boolean,
       value: false,
     },
 
@@ skipping 15 matching lines @@
     },
 
     /**
      * If UI uses forced keyboard navigation.
      */
     highlightStrength: {
       type: String,
       value: '',
     },
 
+    /*
+     * Dynamically change languages.
+     * @private
+     */
+    i18n_: Object,
+
     /**
      * True when connected to a network.
      * @private
      */
     isConnected_: {
       type: Boolean,
       value: false,
     },
 
     /**
      * Controls displaying of "Enable debugging features" link.
      */
-     debuggingLinkVisible: Boolean,
+    debuggingLinkVisible: Boolean,
   },
 
   /**
    * GUID of the user-selected network. It is remembered after user taps on
    * network entry. After we receive event "connected" on this network,
    * OOBE will proceed.
    */
   networkLastSelectedGuid_: '',
 
   /** @override */
@@ skipping 20 matching lines @@
       networkListItemNotConnected:
           loadTimeData.getString('networkListItemNotConnected'),
       vpnNameTemplate: loadTimeData.getString('vpnNameTemplate'),
 
       // Additional strings for custom items.
       addMobileNetworkMenuName:
           loadTimeData.getString('addMobileNetworkMenuName'),
       addWiFiNetworkMenuName: loadTimeData.getString('addWiFiNetworkMenuName'),
       proxySettingsMenuName: loadTimeData.getString('proxySettingsMenuName'),
     };
+
+    // I18n tags in this list are updated in the i18n_ object to reflect the
+    // current i18n locale selected by the user.
+    var i18nTags = [
+      'accessibilitySectionHint', 'accessibilitySectionTitle',
+      'highContrastOption',       'highContrastOptionOff',
+      'highContrastOptionOn',     'keyboardDropdownTitle',
+      'languageDropdownTitle',    'languageSectionTitle',
+      'largeCursorOption',        'largeCursorOptionOff',
+      'largeCursorOptionOn',      'networkSectionHint',
+      'networkSectionTitle',      'oobeOKButtonText',
+      'screenMagnifierOption',    'screenMagnifierOptionOff',
+      'screenMagnifierOptionOn',  'spokenFeedbackOption',
+      'spokenFeedbackOptionOff',  'spokenFeedbackOptionOn',
+      'timezoneDropdownTitle',    'timezoneSectionTitle',
+      'virtualKeyboardOption',    'virtualKeyboardOptionOff',
+      'virtualKeyboardOptionOn',
+    ];
+    var i18n = {};
+    i18nTags.forEach(function(tag) {
+      i18n[tag] = loadTimeData.getString(tag);
+    });
+    this.i18n_ = i18n;

[Alexander Alekseev, 2017/05/19 23:57:29]

Is this an example of what could be done, or a final code?

I really don't like the idea of having a copy of message-ids in the JS source in
addition to HTML. This is error-prone.

Using polymer-based approach, we could have something like
http://stackoverflow.com/a/31129122 .

[dschuyler, 2017/05/20 00:04:56]

I see it as working, potentially final code. I'm good with it being improved
upon following this CL.

[dschuyler, 2017/05/20 00:26:43]

dbeam@ suggested an improvement that may eliminate the need for this list in the
JS. Let me give that a go and put up another patch to see if that looks better.

[dschuyler, 2017/05/20 00:56:09]

WDYT of patch #3

   },
 
   /**
    * Hides all screens to help switching from one screen to another.
    * @private
    */
   hideAllScreens_: function() {
     this.$.welcomeScreen.hidden = true;
 
-    var screens = Polymer.dom(this.root).querySelectorAll('oobe-dialog')
+    var screens = Polymer.dom(this.root).querySelectorAll('oobe-dialog');
     for (var i = 0; i < screens.length; ++i) {
       screens[i].hidden = true;
     }
   },
 
   /**
    * Shows given screen.
    * @param id String Screen ID.
    * @private
    */
   showScreen_: function(id) {
     this.hideAllScreens_();
 
     var screen = this.$[id];
     assert(screen);
     screen.hidden = false;
     screen.show();
   },
 
   /**
    * Returns active screen object.
    * @private
    */
   getActiveScreen_: function() {
-    var screens = Polymer.dom(this.root).querySelectorAll('oobe-dialog')
+    var screens = Polymer.dom(this.root).querySelectorAll('oobe-dialog');
     for (var i = 0; i < screens.length; ++i) {
       if (!screens[i].hidden)
         return screens[i];
     }
     return this.$.welcomeScreen;
   },
 
   focus: function() {
     this.getActiveScreen_().focus();
   },
@@ skipping 22 matching lines @@
    * when connected to a network.
    * @private
    */
   getNetworkCustomItems_: function(isConnected_) {
     var self = this;
     var items = [
       {
         customItemName: 'proxySettingsMenuName',
         polymerIcon: 'oobe-welcome-20:add-proxy',
         customData: {
-          onTap: function() { self.OpenProxySettingsDialog_(); },
+          onTap: function() {
+            self.OpenProxySettingsDialog_();
+          },
         },
       },
       {
         customItemName: 'addWiFiNetworkMenuName',
         polymerIcon: 'oobe-welcome-20:add-wifi',
         customData: {
-          onTap: function() { self.OpenAddWiFiNetworkDialog_(); },
+          onTap: function() {
+            self.OpenAddWiFiNetworkDialog_();
+          },
         },
       },
       {
         customItemName: 'addMobileNetworkMenuName',
         polymerIcon: 'oobe-welcome-20:add-cellular',
         customData: {
-          onTap: function() { self.OpenAddWiFiNetworkDialog_(); },
+          onTap: function() {
+            self.OpenAddWiFiNetworkDialog_();
+          },
         },
       },
     ];
     if (isConnected_)
       return items;
     return items.slice(1);
   },
 
   /**
    * Returns true if timezone button should be visible.
@@ skipping 33 matching lines @@
   /**
    * Handle "Timezone" button for "Welcome" screen.
    *
    * @private
    */
   onWelcomeTimezoneButtonClicked_: function() {
     this.showScreen_('timezoneScreen');
   },
 
   /**
-   * Handle Networwork Setup screen "Proxy settings" button.
+   * Handle Network Setup screen "Proxy settings" button.
    *
    * @private
    */
   OpenProxySettingsDialog_: function(item) {
     chrome.send('launchProxySettingsDialog');
   },
 
   /**
-   * Handle Networwork Setup screen "Add WiFi network" button.
+   * Handle Network Setup screen "Add WiFi network" button.
    *
    * @private
    */
   OpenAddWiFiNetworkDialog_: function(item) {
     chrome.send('launchAddWiFiNetworkDialog');
   },
 
   /**
-   * Handle Networwork Setup screen "Add cellular network" button.
+   * Handle Network Setup screen "Add cellular network" button.
    *
    * @private
    */
   OpenAddMobileNetworkDialog_: function(item) {
     chrome.send('launchAddMobileNetworkDialog');
   },
 
   /**
    * This is called when network setup is done.
    *
@@ skipping 180 matching lines @@
    * @private
    */
   onTimezoneSelected_: function(event) {
     var item = event.detail;
     if (!item)
       return;
 
     this.screen.onTimezoneSelected_(item.value);
   },
 });