From af07d734325d6664af6a7e393a18b035591c1fc6 Mon Sep 17 00:00:00 2001
From: Bruno Windels <brunow@matrix.org>
Date: Mon, 16 Jul 2018 15:07:53 +0200
Subject: [PATCH] hide lazy loading behind feature flag

---
 src/MatrixClientPeg.js                | 4 +++-
 src/components/structures/RoomView.js | 6 +++++-
 src/settings/Settings.js              | 5 +++++
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/MatrixClientPeg.js b/src/MatrixClientPeg.js
index 01a411663c..82d18d307d 100644
--- a/src/MatrixClientPeg.js
+++ b/src/MatrixClientPeg.js
@@ -107,7 +107,9 @@ class MatrixClientPeg {
         // the react sdk doesn't work without this, so don't allow
         opts.pendingEventOrdering = "detached";
 
-        opts.filter = await this.matrixClient.createFilter(FILTER_CONTENT);
+        if (SettingsStore.isFeatureEnabled('feature_lazyloading')) {
+            opts.filter = await this.matrixClient.createFilter(FILTER_CONTENT);
+        }
 
         try {
             const promise = this.matrixClient.store.startup();
diff --git a/src/components/structures/RoomView.js b/src/components/structures/RoomView.js
index 8d4a15642f..2eaf0180a9 100644
--- a/src/components/structures/RoomView.js
+++ b/src/components/structures/RoomView.js
@@ -314,7 +314,11 @@ module.exports = React.createClass({
                 this.setState({isPeeking: false});
 
                 //viewing a previously joined room, try to lazy load members
-                MatrixClientPeg.get().loadRoomMembersIfNeeded(room.roomId);
+
+                // lazy load members if enabled
+                if (SettingsStore.isFeatureEnabled('feature_lazyloading')) {
+                    MatrixClientPeg.get().loadRoomMembersIfNeeded(room.roomId);
+                }
             }
         }
     },
diff --git a/src/settings/Settings.js b/src/settings/Settings.js
index e3f5855f0d..d76c1fd8e8 100644
--- a/src/settings/Settings.js
+++ b/src/settings/Settings.js
@@ -83,6 +83,11 @@ export const SETTINGS = {
         supportedLevels: LEVELS_FEATURE,
         default: false,
     },
+    "feature_lazyloading": {
+        isFeature: true,
+        displayName: _td("Increase performance by loading room members on first view"),
+        supportedLevels: LEVELS_FEATURE,
+    },
     "MessageComposerInput.dontSuggestEmoji": {
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,
         displayName: _td('Disable Emoji suggestions while typing'),