Processing timefences from the server.

chrome/browser/resources/google_now/cards.js

+// Copyright (c) 2013 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.
+
+'use strict';

[arv (Not doing code reviews), 2013/07/25 21:45:27]

Are these files getting concatted?

Usually, it is bad to put 'use strict' at the top level. Can you put this in an
IIFE?

[vadimt, 2013/07/25 22:57:20]

This is one of a page's scripts. Another script of this page depends on its
functions.
I tried surrounding the whole file with an anonymous function, but then exported
methods become local, and I cannot use them outside of the file.
Did you mean something different from a huge anonymous function?

[skare_, 2013/07/26 00:57:29]

(function(){
  window['thefunction'] = thefunction?
})();
?
for reference see also goog.exportSymbol and @export from Closure (though we
don't use it here)

[vadimt, 2013/07/26 01:08:55]

Since I use unit testing, I want to export every function, to be able to test
and mock individual functions. Then, the code (if we apply this rule everywhere)
would become so ugly that the benefits of placing 'use strict' in an IIFE fade.

Speaking of benefits. Given that this code entirely belongs to the extension and
won't be used outside of it, there are not so many benefits in such isolation...

Anyways, technically, I can do what you ask, but I feel that the bottom line
will be losing rather than gaining.

Just let me know if you confirm that you still want me to do this.

+
+var MS_IN_SECOND = 1000;
+
+/**
+ * Builds an object to manage notification cards.
+ * @return {Object} Card manager interface.
+ */
+function buildCardManager() {

[arv (Not doing code reviews), 2013/07/25 21:45:27]

don't name things "manager"

[arv (Not doing code reviews), 2013/07/25 21:45:27]

Use constructor and prototypes if you need multiple objects.

Use the module pattern for a single object

[vadimt, 2013/07/25 22:57:20]

Done.

[vadimt, 2013/07/25 22:57:20]

Module doesn't work well. It creates a variable right here.
However, in my unit tests, I want to call buildCardManager() and check that this
method has correct side effects (like hooking to certain events). I cannot
beautifully do this with a module since by the time a test runs, the module is
already created.

Alternatively, I could declare this as a constructor and a prototype, but this
is inadequate because I create only 1 instance. So, it seems like the current
approach is the most adequate.
Convincing?

+  var cardShowPrefix = 'card-show-';
+  var cardHidePrefix = 'card-hide-';
+
+  /**
+   * Schedules hiding a notification.
+   * @param {string} cardId Card ID.
+   * @param {number=} opt_timeHide If specified, epoch time to hide the card. If
+   *      undefined, the card will be kept shown at least until next update.
+   */
+  function scheduleHiding(cardId, opt_timeHide) {
+    if (opt_timeHide === undefined)
+      return;
+
+    var alarmName = cardHidePrefix + cardId;
+    var alarmInfo = {when: opt_timeHide};
+    chrome.alarms.create(alarmName, alarmInfo);
+  }
+
+  /**
+   * Shows a notification.
+   * @param {string} cardId Card ID.
+   * @param {Object} cardCreateInfo Google Now card represented as a set of
+   *     parameters for showing a Chrome notification.
+   */
+  function showNotification(cardId, cardCreateInfo) {
+    console.log('cardManager.showNotification ' + cardId + ' ' +
+                JSON.stringify(cardCreateInfo));
+
+    if (cardCreateInfo.previousVersion !== cardCreateInfo.version) {
+      try {
+        // Delete a notification with the specified id if it already exists, and
+        // then create a notification.
+        chrome.notifications.create(
+            cardId,
+            cardCreateInfo.notification,
+            function(newNotificationId) {
+              if (!newNotificationId || chrome.runtime.lastError) {
+                var errorMessage = chrome.runtime.lastError &&
+                                   chrome.runtime.lastError.message;
+                console.error('notifications.create: ID=' + newNotificationId +
+                              ', ERROR=' + errorMessage);
+                return;
+              }
+
+              scheduleHiding(cardId, cardCreateInfo.timeHide);
+            });
+      } catch (error) {
+        console.error('Error in notifications.create: ' + error);
+      }
+    } else {
+      try {
+        // Update existing notification.
+        chrome.notifications.update(
+            cardId,
+            cardCreateInfo.notification,
+            function(wasUpdated) {
+              if (!wasUpdated || chrome.runtime.lastError) {
+                var errorMessage = chrome.runtime.lastError &&
+                                   chrome.runtime.lastError.message;
+                console.error('notifications.update: UPDATED=' + wasUpdated +
+                              ', ERROR=' + errorMessage);
+                return;
+              }
+
+              scheduleHiding(cardId, cardCreateInfo.timeHide);
+            });
+      } catch (error) {
+        console.error('Error in notifications.update: ' + error);
+      }
+    }
+  }
+
+  /**
+   * Updates/creates a card notification with new data.
+   * @param {Object} card Google Now from the server.
+   * @param {number=} previousVersion The version of the shown card with
+   *     this id, if it exists, undefined otherwise.
+   * @return {Object} Notification data entry for this card.
+   */
+  function update(card, previousVersion) {
+    console.log('cardManager.update ' + JSON.stringify(card) + ' ' +
+        previousVersion);
+
+    if (typeof card.version != 'number') {
+      console.log('cardCreateInfo.version is not a number');
+      // Fix card version.
+      card.version = previousVersion || 0;
+    }
+
+    // TODO(vadimt): Don't clear alarms etc that don't exist. Or make sure doing
+    // this doesn't output an error to console.
+    chrome.alarms.clear(cardHidePrefix + card.notificationId);
+
+    var timeHide = card.trigger && card.trigger.hideTimeSec !== undefined ?
+        Date.now() + card.trigger.hideTimeSec * MS_IN_SECOND : undefined;
+    var cardCreateInfo = {
+      notification: card.notification,
+      timeHide: timeHide,
+      version: card.version,
+      previousVersion: previousVersion
+    };
+
+    var cardShowAlarmName = cardShowPrefix + card.notificationId;
+    if (card.trigger && card.trigger.showTimeSec) {
+      // Card needs to be shown later.
+      console.log('cardManager.register: postponed');
+      var alarmInfo = {
+        when: Date.now() + card.trigger.showTimeSec * MS_IN_SECOND
+      };
+      chrome.alarms.create(cardShowAlarmName, alarmInfo);
+    } else {
+      // Card needs to be shown immediately.
+      console.log('cardManager.register: immediate');
+      chrome.alarms.clear(cardShowAlarmName);
+      showNotification(card.notificationId, cardCreateInfo);
+    }
+
+    return {
+      actionUrls: card.actionUrls,
+      cardCreateInfo: cardCreateInfo,
+      dismissalParameters: card.dismissal
+    };
+  }
+
+  /**
+   * Removes a card notification.
+   * @param {string} cardId Card ID.
+   */
+  function clear(cardId) {
+    console.log('cardManager.unregister ' + cardId);
+
+    chrome.notifications.clear(cardId, function() {});
+    chrome.alarms.clear(cardShowPrefix + cardId);
+    chrome.alarms.clear(cardHidePrefix + cardId);
+  }
+
+  chrome.alarms.onAlarm.addListener(function(alarm) {
+    console.log('cardManager.onAlarm ' + JSON.stringify(alarm));
+
+    if (alarm.name.indexOf(cardShowPrefix) == 0) {
+      // Alarm to show the card.
+      var cardId = alarm.name.substring(cardShowPrefix.length);
+      storage.get('notificationsData', function(items) {
+        items.notificationsData = items.notificationsData || {};
+        console.log('cardManager.onAlarm.get ' + JSON.stringify(items));
+        var notificationData = items.notificationsData[cardId];
+        if (!notificationData)
+          return;
+
+        showNotification(cardId, notificationData.cardCreateInfo);
+      });
+    } else if (alarm.name.indexOf(cardHidePrefix) == 0) {
+      // Alarm to hide the card.
+      var cardId = alarm.name.substring(cardHidePrefix.length);
+      chrome.notifications.clear(cardId, function() {});
+    }
+  });
+
+  return {
+    update: update,
+    clear: clear
+  };
+}