Added broadcasting of news feeds with incremental updates

Added ability to enable broadcasting of news feed items with `NEWS_FEED` notification and broadcasting updated news feed items with `NEWS_FEED_UPDATE` to other modules. This is merged into the default `newsfeed` module.

One can set ability to broadcast the whole news feed or broadcast only updated news feed items.

CHANGELOG.md

@@ -17,6 +17,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - Russian translation for “Feels”
 - Calendar module: added `nextDaysRelative` config option
 - Add `broadcastPastEvents` config option for calendars to include events from the past `maximumNumberOfDays` in event broadcasts
+- Added feature to broadcast news feed items `NEWS_FEED` and updated news items `NEWS_FEED_UPDATED` in default [newsfeed](https://github.com/MichMich/MagicMirror/tree/develop/modules/default/newsfeed) module (when news is updated) with documented default and `config.js` options in [README.md](https://github.com/MichMich/MagicMirror/blob/develop/modules/default/newsfeed/README.md)
 
 ### Updated
 - English translation for "Feels" to "Feels like"

modules/default/newsfeed/README.md

@@ -48,6 +48,14 @@ MagicMirror's [notification mechanism](https://github.com/MichMich/MagicMirror/t
 | `ARTICLE_TOGGLE_FULL`   | Toggles article in fullscreen.
 | `ARTICLE_INFO_REQUEST`  | Causes `newsfeed` to respond with the notification `ARTICLE_INFO_RESPONSE`, the payload of which provides the `title`, `source`, `date`, `desc` and `url` of the current news title.
 
+#### Notifications sent by the module
+MagicMirror's [notification mechanism](https://github.com/MichMich/MagicMirror/tree/master/modules#thissendnotificationnotification-payload) can also be used to send notifications from the current module to all other modules. The following notifications are broadcasted from this module:
+
+| Notification Identifier | Description
+| ----------------------- | -----------
+| `NEWS_FEED`             | Broadcast the current list of news items.
+| `NEWS_FEED_UPDATE`      | Broadcasts the list of updates news items.
+
 Note the payload of the sent notification event is ignored.
 
 #### Example
@@ -68,6 +76,8 @@ The following properties can be configured:
 | `feeds`            | An array of feed urls that will be used as source. <br> More info about this object can be found below. <br> **Default value:** `[{ title: "New York Times", url: "http://www.nytimes.com/services/xml/rss/nyt/HomePage.xml", encoding: "UTF-8" }]`<br>You can add `reloadInterval` option to set particular reloadInterval to a feed.
 | `showSourceTitle`  | Display the title of the source. <br><br> **Possible values:** `true` or `false` <br> **Default value:** `true`
 | `showPublishDate`  | Display the publish date of an headline. <br><br> **Possible values:** `true` or `false` <br> **Default value:** `true`
+| `broadcastNewsFeeds`   | Gives the ability to broadcast news feeds to all modules, by using ```sendNotification()``` when set to `true`, rather than ```sendSocketNotification()``` when `false` <br><br> **Possible values:** `true` or `false` <br> **Default value:** `true`
+| `broadcastNewsUpdates`   | Gives the ability to broadcast news feed updates to all modules <br><br> **Possible values:** `true` or `false` <br> **Default value:** `true`
 | `showDescription`  | Display the description of an item. <br><br> **Possible values:** `true` or `false` <br> **Default value:** `false`
 | `wrapTitle`        | Wrap the title of the item to multiple lines. <br><br> **Possible values:** `true` or `false` <br> **Default value:** `true`
 | `wrapDescription`  | Wrap the description of the item to multiple lines. <br><br> **Possible values:** `true` or `false` <br> **Default value:** `true`

modules/default/newsfeed/newsfeed.js

@@ -20,6 +20,8 @@ Module.register("newsfeed",{
 		],
 		showSourceTitle: true,
 		showPublishDate: true,
+		broadcastNewsFeeds: true,
+		broadcastNewsUpdates: true,
 		showDescription: false,
 		wrapTitle: true,
 		wrapDescription: true,
@@ -266,6 +268,20 @@ Module.register("newsfeed",{
 			}, this);
 		}
 
+		// get updated news items and broadcast them
+		var updatedItems = [];
+		newsItems.forEach(value => {
+			if (this.newsItems.findIndex(value1 => value1 === value) === -1) {
+				// Add item to updated items list
+				updatedItems.push(value)
+			}
+		});
+
+		// check if updated items exist, if so and if we should broadcast these updates, then lets do so
+		if (this.config.broadcastNewsUpdates && updatedItems.length > 0) {
+			this.sendNotification("NEWS_FEED_UPDATE", {items: updatedItems})
+		}
+
 		this.newsItems = newsItems;
 	},
 
@@ -314,6 +330,11 @@ Module.register("newsfeed",{
 		timer = setInterval(function() {
 			self.activeItem++;
 			self.updateDom(self.config.animationSpeed);
+
+			// Broadcast NewsFeed if needed
+			if (self.config.broadcastNewsFeeds) {
+				self.sendNotification("NEWS_FEED", {items: self.newsItems});
+			}
 		}, this.config.updateInterval);
 	},