Bug 1350409 - Add Store, Actions, and Reducers to Activity Stream system add-on r=ursula

MozReview-Commit-ID: 5lCFGBCtH2e

--HG--
extra : rebase_source : 01e7ae01e1dd03de9fbe84fa1fbc7797323ed475

browser/extensions/activity-stream/common/Actions.jsm

@@ -0,0 +1,19 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+this.actionTypes = [
+  "INIT",
+  "UNINIT",
+// The line below creates an object like this:
+// {
+//   INIT: "INIT",
+//   UNINIT: "UNINIT"
+// }
+// It prevents accidentally adding a different key/value name.
+].reduce((obj, type) => { obj[type] = type; return obj; }, {});
+
+this.EXPORTED_SYMBOLS = [
+  "actionTypes"
+];

browser/extensions/activity-stream/common/Reducers.jsm

@@ -0,0 +1,44 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+this.INITIAL_STATE = {
+  TopSites: {
+    rows: [
+      {
+        "title": "Facebook",
+        "url": "https://www.facebook.com/"
+      },
+      {
+        "title": "YouTube",
+        "url": "https://www.youtube.com/"
+      },
+      {
+        "title": "Amazon",
+        "url": "http://www.amazon.com/"
+      },
+      {
+        "title": "Yahoo",
+        "url": "https://www.yahoo.com/"
+      },
+      {
+        "title": "eBay",
+        "url": "http://www.ebay.com"
+      },
+      {
+        "title": "Twitter",
+        "url": "https://twitter.com/"
+      }
+    ]
+  }
+};
+
+// TODO: Handle some real actions here, once we have a TopSites feed working
+function TopSites(prevState = INITIAL_STATE.TopSites, action) {
+  return prevState;
+}
+
+this.reducers = {TopSites};
+
+this.EXPORTED_SYMBOLS = ["reducers", "INITIAL_STATE"];

browser/extensions/activity-stream/jar.mn

@@ -5,4 +5,6 @@
 [features/activity-stream@mozilla.org] chrome.jar:
 % resource activity-stream %content/
   content/lib/ (./lib/*)
+  content/common/ (./common/*)
+  content/vendor/Redux.jsm (./vendor/Redux.jsm)
   content/data/ (./data/*)

browser/extensions/activity-stream/lib/ActivityStream.jsm

@@ -3,7 +3,10 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 
-class ActivityStream {
+const {utils: Cu} = Components;
+const {Store} = Cu.import("resource://activity-stream/lib/Store.jsm", {});
+
+this.ActivityStream = class ActivityStream {
 
   /**
    * constructor - Initializes an instance of ActivityStream
@@ -16,13 +19,16 @@ class ActivityStream {
   constructor(options) {
     this.initialized = false;
     this.options = options;
+    this.store = new Store();
   }
   init() {
     this.initialized = true;
+    this.store.init();
   }
   uninit() {
+    this.store.uninit();
     this.initialized = false;
   }
-}
+};
 
 this.EXPORTED_SYMBOLS = ["ActivityStream"];

browser/extensions/activity-stream/lib/Store.jsm

@@ -0,0 +1,78 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+const {utils: Cu} = Components;
+
+const {redux} = Cu.import("resource://activity-stream/vendor/Redux.jsm", {});
+const {actionTypes: at} = Cu.import("resource://activity-stream/common/Actions.jsm", {});
+const {reducers} = Cu.import("resource://activity-stream/common/Reducers.jsm", {});
+
+/**
+ * Store - This has a similar structure to a redux store, but includes some extra
+ *         functionality. It accepts an array of "Feeds" on inititalization, which
+ *         can listen for any action that is dispatched through the store.
+ */
+this.Store = class Store {
+
+  /**
+   * constructor - The redux store is created here,
+   *               but no listeners are added until "init" is called.
+   */
+  constructor() {
+    this._middleware = this._middleware.bind(this);
+    // Bind each redux method so we can call it directly from the Store. E.g.,
+    // store.dispatch() will call store._store.dispatch();
+    ["dispatch", "getState", "subscribe"].forEach(method => {
+      this[method] = function(...args) {
+        return this._store[method](...args);
+      }.bind(this);
+    });
+    this.feeds = new Set();
+    this._store = redux.createStore(
+      redux.combineReducers(reducers),
+      redux.applyMiddleware(this._middleware)
+    );
+  }
+
+  /**
+   * _middleware - This is redux middleware consumed by redux.createStore.
+   *               it calls each feed's .onAction method, if one
+   *               is defined.
+   */
+  _middleware(store) {
+    return next => action => {
+      next(action);
+      this.feeds.forEach(s => s.onAction && s.onAction(action));
+    };
+  }
+
+  /**
+   * init - Initializes the MessageManager channel, and adds feeds.
+   *        After initialization has finished, an INIT action is dispatched.
+   *
+   * @param  {array} feeds An array of objects with an optional .onAction method
+   */
+  init(feeds) {
+    if (feeds) {
+      feeds.forEach(subscriber => {
+        subscriber.store = this;
+        this.feeds.add(subscriber);
+      });
+    }
+    this.dispatch({type: at.INIT});
+  }
+
+  /**
+   * uninit - Clears all feeds, dispatches an UNINIT action
+   *
+   * @return {type}  description
+   */
+  uninit() {
+    this.feeds.clear();
+    this.dispatch({type: at.UNINIT});
+  }
+};
+
+this.EXPORTED_SYMBOLS = ["Store"];