Index: backup/moodle2/backup_chat_activity_task.class.php
=========================================================
--- backup/moodle2/backup_chat_activity_task.class.php	Thu May 06 12:10:06 WST 2010
+++ backup/moodle2/backup_chat_activity_task.class.php	Thu May 06 12:10:06 WST 2010
@@ -0,0 +1,86 @@
+<?php
+
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * This is the "graphical" structure of the chat mod:
+ *
+ *                        chat
+ *                     (CL,pk->id)
+ *                         |
+ *                         |
+ *                         |
+ *                    chat_messages
+ *                (UL,pk->id, fk->chatid)
+ * 
+ *  Meaning: pk->primary key field of the table
+ *           fk->foreign key to link with parent
+ *           nt->nested field (recursive data)
+ *           CL->course level info
+ *           UL->user level info
+ *
+ * @package moodlecore
+ * @subpackage backup-moodle2
+ * @copyright 2010 onwards Dongsheng Cai <dongsheng@moodle.com>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+require_once($CFG->dirroot . '/mod/chat/backup/moodle2/backup_chat_stepslib.php'); // Because it exists (must)
+require_once($CFG->dirroot . '/mod/chat/backup/moodle2/backup_chat_settingslib.php'); // Because it exists (optional)
+
+/**
+ * chat backup task that provides all the settings and steps to perform one
+ * complete backup of the activity
+ */
+class backup_chat_activity_task extends backup_activity_task {
+
+    /**
+     * Define (add) particular settings this activity can have
+     */
+    protected function define_my_settings() {
+        // No particular settings for this activity
+    }
+
+    /**
+     * Define (add) particular steps this activity can have
+     */
+    protected function define_my_steps() {
+        // chat only has one structure step
+        $this->add_step(new backup_chat_activity_structure_step('chat_structure', 'chat.xml'));
+    }
+
+    /**
+     * Code the transformations to perform in the chat activity in
+     * order to get transportable (encoded) links
+     *
+     * @param string $content
+     * @return string
+     */
+    static public function encode_content_links($content) {
+        global $CFG;
+
+        $base = preg_quote($CFG->wwwroot.'/mod/chat','#');
+
+        //Link to the list of chats
+        $pattern = "#(".$base."\/index.php\?id\=)([0-9]+)#";
+        $content = preg_replace($pattern, '$@CHATINDEX*$2@$', $content);
+
+        //Link to chat view by moduleid
+        $pattern = "#(".$base."\/view.php\?id\=)([0-9]+)#";
+        $content = preg_replace($pattern, '$@CHATVIEWBYID*$2@$', $content);
+
+        return $content;
+    }
+}
Index: backup/moodle2/backup_chat_settingslib.php
=========================================================
--- backup/moodle2/backup_chat_settingslib.php	Thu May 06 11:07:41 WST 2010
+++ backup/moodle2/backup_chat_settingslib.php	Thu May 06 11:07:41 WST 2010
@@ -0,0 +1,27 @@
+<?php
+
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * @package moodlecore
+ * @subpackage backup-moodle2
+ * @copyright 2010 onwards Dongsheng Cai <dongsheng@moodle.com>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+ // This activity has not particular settings but the inherited from the generic
+ // backup_activity_task so here there isn't any class definition, like the ones
+ // existing in /backup/moodle2/backup_settingslib.php (activities section)?php
Index: backup/moodle2/backup_chat_stepslib.php
=========================================================
--- backup/moodle2/backup_chat_stepslib.php	Thu May 06 11:52:57 WST 2010
+++ backup/moodle2/backup_chat_stepslib.php	Thu May 06 11:52:57 WST 2010
@@ -0,0 +1,66 @@
+<?php
+
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * @package moodlecore
+ * @subpackage backup-moodle2
+ * @copyright 2010 onwards Dongsheng Cai <dongsheng@moodle.com>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+/**
+ * Define all the backup steps that will be used by the backup_chat_activity_task
+ */
+class backup_chat_activity_structure_step extends backup_activity_structure_step {
+    protected function define_structure() {
+        $userinfo = $this->get_setting_value('userinfo');
+
+        // Define each element separated
+        $chat = new backup_nested_element('chat', array('id'), array(
+            'name', 'intro', 'introformat', 'keepdays', 'studentlogs',
+            'chattime', 'schedule', 'timemodified'));
+        $messages = new backup_nested_element('messages');
+
+        $message = new backup_nested_element('message', array('id'), array('userid', 'groupid', 'system', 'message', 'timestamp'));
+
+        // Build the tree
+        $chat->add_child($messages);
+            $messages->add_child($message);
+
+        // Define sources
+        $chat->set_source_table('chat', array('id' => backup::VAR_ACTIVITYID));
+
+        // User related messages only happen if we are including user info
+        if ($userinfo) {
+            $message->set_source_sql('
+                 SELECT *
+                 FROM {chat_messages}
+                 WHERE chatid = ?',
+                 array(backup::VAR_PARENTID)
+             );
+        }
+
+        // Define id annotations
+        $message->annotate_ids('user', 'userid');
+        $message->annotate_ids('group', 'groupid');
+
+        // chat don't use files, so no files need to be processed here
+
+        // Return the root element (chat), wrapped into standard activity structure
+        return $this->prepare_activity_structure($chat);
+    }
+}
Index: lib.php
=========================================================
--- lib.php	(revision 1.169)
+++ lib.php	Wed May 05 16:39:22 WST 2010
@@ -1221,6 +1221,7 @@
         case FEATURE_GROUPINGS:               return true;
         case FEATURE_GROUPMEMBERSONLY:        return true;
         case FEATURE_MOD_INTRO:               return true;
+        case FEATURE_BACKUP_MOODLE2:          return true;
         case FEATURE_COMPLETION_TRACKS_VIEWS: return false;
         case FEATURE_GRADE_HAS_GRADE:         return false;
         case FEATURE_GRADE_OUTCOMES:          return true;