Merge pull request #2118 from matrix-org/bwindels/feature_lazyloading

Lazy loading of room members

src/components/structures/RoomView.js

@@ -309,9 +309,21 @@ module.exports = React.createClass({
                     }
                 });
             } else if (room) {
+                //viewing a previously joined room, try to lazy load members
+                
                 // Stop peeking because we have joined this room previously
                 MatrixClientPeg.get().stopPeeking();
                 this.setState({isPeeking: false});
+
+                // lazy load members if enabled
+                if (SettingsStore.isFeatureEnabled('feature_lazyloading')) {
+                    room.loadMembersIfNeeded().catch((err) => {
+                        const errorMessage = `Fetching room members for ${this.roomId} failed.` +
+                            " Room members will appear incomplete.";
+                        console.error(errorMessage);
+                        console.error(err);
+                    });
+                }
             }
         }
     },
@@ -746,40 +758,13 @@ module.exports = React.createClass({
     },
 
     _updateDMState() {
-        const me = this.state.room.getMember(MatrixClientPeg.get().credentials.userId);
-        if (!me || me.membership !== "join") {
+        const room = this.state.room;
+        if (room.getMyMembership() != "join") {
             return;
         }
-
-        // The user may have accepted an invite with is_direct set
-        if (me.events.member.getPrevContent().membership === "invite" &&
-            me.events.member.getPrevContent().is_direct
-        ) {
-            // This is a DM with the sender of the invite event (which we assume
-            // preceded the join event)
-            Rooms.setDMRoom(
-                this.state.room.roomId,
-                me.events.member.getUnsigned().prev_sender,
-            );
-            return;
-        }
-
-        const invitedMembers = this.state.room.getMembersWithMembership("invite");
-        const joinedMembers = this.state.room.getMembersWithMembership("join");
-
-        // There must be one invited member and one joined member
-        if (invitedMembers.length !== 1 || joinedMembers.length !== 1) {
-            return;
-        }
-
-        // The user may have sent an invite with is_direct sent
-        const other = invitedMembers[0];
-        if (other &&
-            other.membership === "invite" &&
-            other.events.member.getContent().is_direct
-        ) {
-            Rooms.setDMRoom(this.state.room.roomId, other.userId);
-            return;
+        const dmInviter = room.getDMInviter();
+        if (dmInviter) {
+            Rooms.setDMRoom(room.roomId, dmInviter);
         }
     },
 

src/components/structures/UserSettings.js

@@ -844,8 +844,16 @@ module.exports = React.createClass({
         SettingsStore.getLabsFeatures().forEach((featureId) => {
             // TODO: this ought to be a separate component so that we don't need
             // to rebind the onChange each time we render
-            const onChange = (e) => {
-                SettingsStore.setFeatureEnabled(featureId, e.target.checked);
+            const onChange = async (e) => {
+                const checked = e.target.checked;
+                if (featureId === "feature_lazyloading") {
+                    const confirmed = await this._onLazyLoadChanging(checked);
+                    if (!confirmed) {
+                        e.preventDefault();
+                        return;
+                    }
+                }
+                await SettingsStore.setFeatureEnabled(featureId, checked);
                 this.forceUpdate();
             };
 
@@ -855,7 +863,7 @@ module.exports = React.createClass({
                         type="checkbox"
                         id={featureId}
                         name={featureId}
-                        defaultChecked={SettingsStore.isFeatureEnabled(featureId)}
+                        checked={SettingsStore.isFeatureEnabled(featureId)}
                         onChange={onChange}
                     />
                     <label htmlFor={featureId}>{ SettingsStore.getDisplayName(featureId) }</label>
@@ -878,6 +886,30 @@ module.exports = React.createClass({
         );
     },
 
+    _onLazyLoadChanging: async function(enabling) {
+        // don't prevent turning LL off when not supported
+        if (enabling) {
+            const supported = await MatrixClientPeg.get().doesServerSupportLazyLoading();
+            if (!supported) {
+                await new Promise((resolve) => {
+                    const QuestionDialog = sdk.getComponent("dialogs.QuestionDialog");
+                    Modal.createDialog(QuestionDialog, {
+                        title: _t("Lazy loading members not supported"),
+                        description:
+                            <div>
+                         { _t("Lazy loading is not supported by your " +
+                            "current homeserver.") }
+                            </div>,
+                        button: _t("OK"),
+                        onFinished: resolve,
+                    });
+                });
+                return false;
+            }
+        }
+        return true;
+    },
+
     _renderDeactivateAccount: function() {
         return <div>
             <h3>{ _t("Deactivate Account") }</h3>