From 1302bb08f62c72a4685fbd4a2d1a8ee438f4fc26 Mon Sep 17 00:00:00 2001
From: Marina Glancy <marina@moodle.com>
Date: Fri, 8 Aug 2014 14:32:41 +0800
Subject: [PATCH] MDL-43739 block_course_overview: allow resorting of big
 number of courses

previously an exception was thrown if the user preference exceeds 1333 chars
---
 blocks/course_overview/locallib.php | 33 +++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/blocks/course_overview/locallib.php b/blocks/course_overview/locallib.php
index 5bd7f4264c2..df9444524cd 100644
--- a/blocks/course_overview/locallib.php
+++ b/blocks/course_overview/locallib.php
@@ -59,10 +59,34 @@ function block_course_overview_update_mynumber($number) {
 /**
  * Sets user course sorting preference in course_overview block
  *
- * @param array $sortorder sort order of course
+ * @param array $sortorder list of course ids
  */
 function block_course_overview_update_myorder($sortorder) {
-    set_user_preference('course_overview_course_order', serialize($sortorder));
+    $value = implode(',', $sortorder);
+    if (core_text::strlen($value) > 1333) {
+        // The value won't fit into the user preference. Remove courses in the end of the list (mostly likely user won't even notice).
+        $value = preg_replace('/,[\d]*$/', '', core_text::substr($value, 0, 1334));
+    }
+    set_user_preference('course_overview_course_sortorder', $value);
+}
+
+/**
+ * Gets user course sorting preference in course_overview block
+ *
+ * @return array list of course ids
+ */
+function block_course_overview_get_myorder() {
+    if ($value = get_user_preferences('course_overview_course_sortorder')) {
+        return explode(',', $value);
+    }
+    // If preference was not found, look in the old location and convert if found.
+    $order = array();
+    if ($value = get_user_preferences('course_overview_course_order')) {
+        $order = unserialize($value);
+        block_course_overview_update_myorder($order);
+        unset_user_preference('course_overview_course_order');
+    }
+    return $order;
 }
 
 /**
@@ -167,10 +191,7 @@ function block_course_overview_get_sorted_courses($showallcourses = false) {
         $courses[$remoteid] = $val;
     }
 
-    $order = array();
-    if (!is_null($usersortorder = get_user_preferences('course_overview_course_order'))) {
-        $order = unserialize($usersortorder);
-    }
+    $order = block_course_overview_get_myorder();
 
     $sortedcourses = array();
     $counter = 0;