PLT-1125: allow to toggle features in frontend

web/react/utils/client.jsx

@@ -1320,3 +1320,16 @@ export function regenOutgoingHookToken(data, success, error) {
         }
     });
 }
+
+export function getAvailablePreReleaseFeatures(success, error) {
+    $.ajax({
+        url: '/static/config/pre_release_features.json',
+        dataType: 'json',
+        type: 'GET',
+        success,
+        error: (xhr, status, err) => {
+            var e = handleError('getAvailablePreReleaseFeatures', xhr, status, err);
+            error(e);
+        }
+    });
+}

web/react/utils/utils.jsx

@@ -1221,3 +1221,7 @@ export function getPostTerm(post) {
 
     return postTerm;
 }
+
+export function featureToggle(feature) {
+    return PreferenceStore.getPreference(Constants.Preferences.CATEGORY_ADVANCED_SETTINGS, 'feature_enabled_' + feature, {value: 'false'}).value === 'true';
+}