From 7f9358fcc05b52e57d2c68257ad9585962972ba9 Mon Sep 17 00:00:00 2001
From: Marina Glancy <marina@moodle.com>
Date: Wed, 7 Mar 2012 11:25:18 +0800
Subject: [PATCH] MDL-31838: Allow caching static responses from repositories
 in file picker

---
 repository/filepicker.js  | 18 +++++++++++++++---
 repository/upload/lib.php |  1 +
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/repository/filepicker.js b/repository/filepicker.js
index 72d0a5668e82e..c9307e3a281a6 100644
--- a/repository/filepicker.js
+++ b/repository/filepicker.js
@@ -72,6 +72,7 @@ M.core_filepicker.init = function(Y, options) {
 
     Y.extend(FilePickerHelper, Y.Base, {
         api: M.cfg.wwwroot+'/repository/repository_ajax.php',
+        cached_responses: {},
 
         initializer: function(options) {
             this.options = options;
@@ -163,6 +164,11 @@ M.core_filepicker.init = function(Y, options) {
                             if (data.msg) {
                                 scope.print_msg(data.msg, 'info');
                             }
+                            // cache result if applicable
+                            if (args.action != 'upload' && data.allowcaching) {
+                                scope.cached_responses[params] = data;
+                            }
+                            // invoke callback
                             args.callback(id,data,p);
                         }
                     }
@@ -179,9 +185,15 @@ M.core_filepicker.init = function(Y, options) {
             if (args.form) {
                 cfg.form = args.form;
             }
-            Y.io(api, cfg);
-            if (redraw) {
-                this.wait('load');
+            // check if result of the same request has been already cached. If not, request it
+            // (never applicable in case of form submission and/or upload action):
+            if (!args.form && args.action != 'upload' && scope.cached_responses[params]) {
+                args.callback(null, scope.cached_responses[params], {scope: scope})
+            } else {
+                Y.io(api, cfg);
+                if (redraw) {
+                    this.wait('load');
+                }
             }
         },
         process_existing_file: function(data) {
diff --git a/repository/upload/lib.php b/repository/upload/lib.php
index 3dc6330eea11c..447fd0861e5c5 100644
--- a/repository/upload/lib.php
+++ b/repository/upload/lib.php
@@ -223,6 +223,7 @@ public function get_listing() {
         $ret['list'] = array();
         $ret['dynload'] = false;
         $ret['upload'] = array('label'=>get_string('attachment', 'repository'), 'id'=>'repo-form');
+        $ret['allowcaching'] = true; // indicates that result of get_listing() can be cached in filepicker.js
         return $ret;
     }