From 0887f755877a90d5310155d1c6542e2319c5c21e Mon Sep 17 00:00:00 2001
From: Damyon Wiese <damyon@moodle.com>
Date: Tue, 11 Dec 2012 14:47:33 +0800
Subject: [PATCH] MDL-30700 Assignment 2.2: Added text_sorting function to
 tablelib

Allows oracle to sort by text (clob) columns (should be used sparingly).
---
 lib/tablelib.php       | 17 +++++++++++++++--
 mod/assignment/lib.php |  1 +
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/lib/tablelib.php b/lib/tablelib.php
index 2a08616859e..57796bbc52e 100644
--- a/lib/tablelib.php
+++ b/lib/tablelib.php
@@ -60,6 +60,7 @@ class flexible_table {
     var $column_class    = array();
     var $column_suppress = array();
     var $column_nosort   = array('userpic');
+    private $column_textsort = array();
     var $setup           = false;
     var $sess            = NULL;
     var $baseurl         = NULL;
@@ -214,6 +215,14 @@ class flexible_table {
         $this->sort_default_order  = $defaultorder;
     }
 
+    /**
+     * Use text sorting functions for this column (required for text columns with Oracle).
+     * @param string column name
+     */
+    function text_sorting($column) {
+        $this->column_textsort[] = $column;
+    }
+
     /**
      * Do not sort using this column
      * @param string column name
@@ -513,10 +522,14 @@ class flexible_table {
      * @param array $cols column name => SORT_ASC or SORT_DESC
      * @return SQL fragment that can be used in an ORDER BY clause.
      */
-    public static function construct_order_by($cols) {
+    public static function construct_order_by($cols, $textsortcols=array()) {
+        global $DB;
         $bits = array();
 
         foreach ($cols as $column => $order) {
+            if (in_array($column, $textsortcols)) {
+                $column = $DB->sql_order_by_text($column);
+            }
             if ($order == SORT_ASC) {
                 $bits[] = $column . ' ASC';
             } else {
@@ -531,7 +544,7 @@ class flexible_table {
      * @return SQL fragment that can be used in an ORDER BY clause.
      */
     public function get_sql_sort() {
-        return self::construct_order_by($this->get_sort_columns());
+        return self::construct_order_by($this->get_sort_columns(), $this->column_textsort);
     }
 
     /**
diff --git a/mod/assignment/lib.php b/mod/assignment/lib.php
index 01043317038..3688ac9590f 100644
--- a/mod/assignment/lib.php
+++ b/mod/assignment/lib.php
@@ -1380,6 +1380,7 @@ class assignment_base {
 
         $table->no_sorting('finalgrade');
         $table->no_sorting('outcome');
+        $table->text_sorting('submissioncomment');
 
         // Start working -- this is necessary as soon as the niceties are over
         $table->setup();