From dbb8cd36bd7e102a331c242c36d6f4d0fcb7c4c7 Mon Sep 17 00:00:00 2001
From: Adrian Greeve <adrian@moodle.com>
Date: Tue, 16 Jul 2013 13:58:03 +0800
Subject: [PATCH] MDL-40038 - web services: Added an alternative to using the
 context id.

Context id is more of an internal Moodle identifier, so we have now included
contextlevel and instanceid in the funciton core_files_external::get_files().
---
 files/externallib.php | 52 ++++++++++++++++++++++++++++++-------------
 1 file changed, 37 insertions(+), 15 deletions(-)

diff --git a/files/externallib.php b/files/externallib.php
index f2b0ab6f92d..75c81ebe03b 100644
--- a/files/externallib.php
+++ b/files/externallib.php
@@ -47,13 +47,16 @@ class core_files_external extends external_api {
     public static function get_files_parameters() {
         return new external_function_parameters(
             array(
-                'contextid' => new external_value(PARAM_INT, 'context id'),
-                'component' => new external_value(PARAM_TEXT, 'component'),
-                'filearea'  => new external_value(PARAM_TEXT, 'file area'),
-                'itemid'    => new external_value(PARAM_INT, 'associated id'),
-                'filepath'  => new external_value(PARAM_PATH, 'file path'),
-                'filename'  => new external_value(PARAM_FILE, 'file name'),
-                'modified' => new external_value(PARAM_INT, 'timestamp to return files changed after this time.', VALUE_DEFAULT, null)
+                'contextid'    => new external_value(PARAM_INT, 'context id Set to -1 to use contextlevel and instanceid.'),
+                'component'    => new external_value(PARAM_TEXT, 'component'),
+                'filearea'     => new external_value(PARAM_TEXT, 'file area'),
+                'itemid'       => new external_value(PARAM_INT, 'associated id'),
+                'filepath'     => new external_value(PARAM_PATH, 'file path'),
+                'filename'     => new external_value(PARAM_FILE, 'file name'),
+                'modified'     => new external_value(PARAM_INT, 'timestamp to return files changed after this time.', VALUE_DEFAULT, null),
+                'contextlevel' => new external_value(PARAM_ALPHA, 'The context level for the file location.', VALUE_DEFAULT, null),
+                'instanceid'   => new external_value(PARAM_INT, 'The instance id for where the file is located.', VALUE_DEFAULT, null)
+
             )
         );
     }
@@ -68,22 +71,41 @@ class core_files_external extends external_api {
      * @param string $filepath file path
      * @param string $filename file name
      * @param int $modified timestamp to return files changed after this time.
+     * @param string $contextlevel The context level for the file location.
+     * @param int $instanceid The instance id for where the file is located.
      * @return array
      * @since Moodle 2.2
      */
-    public static function get_files($contextid, $component, $filearea, $itemid, $filepath, $filename, $modified = null) {
-        global $CFG, $USER, $OUTPUT;
-        $fileinfo = self::validate_parameters(self::get_files_parameters(), array(
-                    'contextid'=>$contextid, 'component'=>$component, 'filearea'=>$filearea,
-                    'itemid'=>$itemid, 'filepath'=>$filepath, 'filename'=>$filename, 'modified'=>$modified));
+    public static function get_files($contextid, $component, $filearea, $itemid, $filepath, $filename, $modified = null,
+                                     $contextlevel = null, $instanceid = null) {
+
+        $parameters = array(
+            'contextid'    => $contextid,
+            'component'    => $component,
+            'filearea'     => $filearea,
+            'itemid'       => $itemid,
+            'filepath'     => $filepath,
+            'filename'     => $filename,
+            'modified'     => $modified,
+            'contextlevel' => $contextlevel,
+            'instanceid'   => $instanceid);
+        $fileinfo = self::validate_parameters(self::get_files_parameters(), $parameters);
 
         $browser = get_file_browser();
 
-        if (empty($fileinfo['contextid'])) {
-            $context  = context_system::instance();
+        // We need to preserve backwards compatibility. Zero will use the system context and minus one will
+        // use the addtional parameters to determine the context.
+        // TODO MDL-40489 get_context_from_params should handle this logic.
+        if ($fileinfo['contextid'] == 0) {
+            $context = context_system::instance();
         } else {
-            $context  = context::instance_by_id($fileinfo['contextid']);
+            if ($fileinfo['contextid'] == -1) {
+                $fileinfo['contextid'] = null;
+            }
+            $context = self::get_context_from_params($fileinfo);
         }
+        self::validate_context($context);
+
         if (empty($fileinfo['component'])) {
             $fileinfo['component'] = null;
         }