Handle accountData events from TagOrderStore

This introduces a generic way to register certain events emitted by
the js-sdk as those that should be propagated through as dispatched
actions.

This allows the store to treat the js-sdk as the "Server" in the
Flux data flow model. It also allows for stores to not be aware
specifically of the matrix client if they are only reading from it.

src/MatrixClientPeg.js

@@ -22,6 +22,7 @@ import EventTimeline from 'matrix-js-sdk/lib/models/event-timeline';
 import EventTimelineSet from 'matrix-js-sdk/lib/models/event-timeline-set';
 import createMatrixClient from './utils/createMatrixClient';
 import SettingsStore from './settings/SettingsStore';
+import MatrixActionCreators from './actions/MatrixActionCreators';
 
 interface MatrixClientCreds {
     homeserverUrl: string,
@@ -68,6 +69,8 @@ class MatrixClientPeg {
 
     unset() {
         this.matrixClient = null;
+
+        MatrixActionCreators.stop();
     }
 
     /**
@@ -108,6 +111,9 @@ class MatrixClientPeg {
         // regardless of errors, start the client. If we did error out, we'll
         // just end up doing a full initial /sync.
 
+        // Connect the matrix client to the dispatcher
+        MatrixActionCreators.start(this.matrixClient);
+
         console.log(`MatrixClientPeg: really starting MatrixClient`);
         this.get().startClient(opts);
         console.log(`MatrixClientPeg: MatrixClient started`);

src/actions/GroupActions.js

@@ -14,7 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-
 import { createPromiseActionCreator } from './actionCreators';
 
 const GroupActions = {};

src/actions/MatrixActionCreators.js

@@ -0,0 +1,39 @@
+/*
+Copyright 2017 Vector Creations Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { createMatrixActionCreator } from './actionCreators';
+
+// Events emitted from the matrixClient that we want to dispatch as actions
+// via MatrixActionCreators. See createMatrixActionCreator.
+const REGISTERED_EVENTS = [
+    "accountData",
+];
+
+export default {
+    actionCreators: [],
+    actionCreatorsStop: [],
+
+    start(matrixClient) {
+        this.actionCreators = REGISTERED_EVENTS.map((eventId) =>
+            createMatrixActionCreator(matrixClient, eventId),
+        );
+        this.actionCreatorsStop = this.actionCreators.map((ac) => ac());
+    },
+
+    stop() {
+        this.actionCreatorsStop.map((stop) => stop());
+    },
+};

src/actions/actionCreators.js

@@ -16,6 +16,16 @@ limitations under the License.
 
 import dis from '../dispatcher';
 
+/**
+ * Create an action creator that will dispatch actions asynchronously that
+ * indicate the current status of promise returned by the given function, fn.
+ * @param {string} id the id to give the dispatched actions. This is given a
+ *                   suffix determining whether it is pending, successful or
+ *                   a failure.
+ * @param {function} fn the function to call with arguments given to the
+ *                   returned function. This function should return a Promise.
+ * @returns a function that dispatches asynchronous actions when called.
+ */
 export function createPromiseActionCreator(id, fn) {
     return (...args) => {
         dis.dispatch({action: id + '.pending'});
@@ -26,3 +36,37 @@ export function createPromiseActionCreator(id, fn) {
         })
     }
 }
+
+/**
+ * Create an action creator that will listen to events of type eventId emitted
+ * by matrixClient and dispatch a corresponding action of the following shape:
+ *     {
+ *         action: 'MatrixActions.' + eventId,
+ *         event: matrixEvent,
+ *         event_type: matrixEvent.getType(),
+ *         event_content: matrixEvent.getContent(),
+ *     }
+ * @param matrixClient{MatrixClient} the matrix client with which to register
+ *                                   a listener.
+ * @param eventId{string} the ID of the event that hen emitted will cause the
+ *                        an action to be dispatched.
+ * @returns a function that, when called, will begin to listen to dispatches
+ *          from matrixClient. The result from that function can be called to
+ *          stop listening.
+ */
+export function createMatrixActionCreator(matrixClient, eventId) {
+    const listener = (matrixEvent) => {
+        dis.dispatch({
+            action: 'MatrixActions.' + eventId,
+            event: matrixEvent,
+            event_type: matrixEvent.getType(),
+            event_content: matrixEvent.getContent(),
+        });
+    };
+    return () => {
+        matrixClient.on(eventId, listener);
+        return () => {
+            matrixClient.removeListener(listener);
+        }
+    }
+}

src/stores/TagOrderStore.js

@@ -41,17 +41,14 @@ class TagOrderStore extends Store {
 
     __onDispatch(payload) {
         switch (payload.action) {
-            // Get ordering from account data, once the client has synced
-            case 'sync_state':
-                if (payload.prevState === "PREPARED" && payload.state === "SYNCING") {
-                    const accountDataEvent = MatrixClientPeg.get().getAccountData('im.vector.web.tag_ordering');
-
-                    const orderedTags = accountDataEvent && accountDataEvent.getContent() ?
-                        accountDataEvent.getContent().tags : null;
-
-                    this._setState({orderedTags});
-                }
-            break;
+            // Get ordering from account data
+            case 'MatrixActions.accountData': {
+                if (payload.event_type !== 'im.vector.web.tag_ordering') break;
+                this._setState({
+                    orderedTags: payload.event_content ? payload.event_content.tags : null,
+                });
+                break;
+            }
             // Initialise the state such that if account data is unset, default to joined groups
             case 'GroupActions.fetchJoinedGroups.success':
                 this._setState({