Issue phonegap#293: Force notification on Android to be background if…

… content-available: 1

docs/PAYLOAD.md

@@ -289,27 +289,28 @@ This will produce the following notification in your tray:
 
 On Android if you want your `on('notification')` event handler to be called when your app is in the background it is relatively simple.
 
-The JSON you send to GCM should not contain a title or message parameter. For instance the following JSON:
+First the JSON you send from GCM will need to include `"content-available": "1"`. This will tell the push plugin to call your `on('notification')` event handler no matter what other data is in the push notification.
 
 ```javascript
 {
 	title: "Test Push",
 	message: "Push number 1",
-	info: "super secret info"
+	info: "super secret info",
+	content-available: "1"
 }
 ```
 
-will produce a notification in the notification shade and call your `on('notification')` event handler.
+or 
 
-However if you want your `on('notification')` event handler called but no notification to be shown in the shader you would omit the `alert` property and send the following JSON to GCM:
 
 ```javascript
 {
-	info: "super secret info"
+	info: "super secret info",
+	content-available: "1"
 }
 ```
 
-Omitting the message and title properties will keep your push from being added to the notification shade but it will still trigger your `on('notification')` event handler.
+If do not want this type of behaviour just omit `"content-available": 1` from your push data and your `on('notification')` event handler will not be called.
 
 # iOS Behaviour
 
@@ -341,7 +342,7 @@ For instance the following JSON:
 {
 	aps: {
 		alert: "Test background push",
-		"content-available": 1
+		content-available: 1
 	}
 }
 ```
@@ -355,7 +356,7 @@ However if you want your `on('notification')` event handler called but no notifi
 	aps: {
 		data: "Test silent background push",
 		moredata: "Do more stuff",
-		"content-available": 1
+		content-available: 1
 	}
 }
 ```

src/android/com/adobe/phonegap/push/GCMIntentService.java

@@ -196,17 +196,21 @@ private void showNotificationIfPossible (Context context, Bundle extras) {
         // Send a notification if there is a message or title, otherwise just send data
         String message = extras.getString(MESSAGE);
         String title = extras.getString(TITLE);
+        String contentAvailable = extras.getString(CONTENT_AVAILABLE);
 
         Log.d(LOG_TAG, "message =[" + message + "]");
         Log.d(LOG_TAG, "title =[" + title + "]");
+        Log.d(LOG_TAG, "contentAvailable =[" + contentAvailable + "]");
 
         if ((message != null && message.length() != 0) ||
                 (title != null && title.length() != 0)) {
 
             Log.d(LOG_TAG, "create notification");
 
             createNotification(context, extras);
-        } else {
+        }
+
+        if ("1".equals(contentAvailable)) {
             Log.d(LOG_TAG, "send notification event");
             PushPlugin.sendExtras(extras);
         }

src/android/com/adobe/phonegap/push/PushConstants.java

@@ -51,4 +51,5 @@ public interface PushConstants {
     public static final String COLLAPSE_KEY = "collapse_key";
     public static final String FORCE_SHOW = "forceShow";
     public static final String GCM = "GCM";
+    public static final String CONTENT_AVAILABLE = "content-available";
 }