MDL-24177 backup - fix page next/prev ids to be propely mapped

mod/lesson/backup/moodle2/restore_lesson_stepslib.php

@@ -74,8 +74,8 @@ protected function process_lesson_page($data) {
         $data = (object)$data;
         $oldid = $data->id;
         $data->lessonid = $this->get_new_parentid('lesson');
-        $data->prevpageid = (empty($data->prevpageid)) ? 0 : $this->get_mappingid('lesson_page', $data->prevpageid);
-        $data->nextpageid = 0; //we don't know the id of the next page as it hasn't been created yet.
+
+        // We'll remap all the prevpageid and nextpageid at the end, once all pages have been created
         $data->timemodified = $this->apply_date_offset($data->timemodified);
         $data->timecreated = $this->apply_date_offset($data->timecreated);
 
@@ -169,11 +169,23 @@ protected function process_lesson_timer($data) {
     }
 
     protected function after_execute() {
+        global $DB;
+
         // Add lesson mediafile, no need to match by itemname (just internally handled context)
         $this->add_related_files('mod_lesson', 'mediafile', null);
         // Add lesson page files, by lesson_page itemname
         $this->add_related_files('mod_lesson', 'page_contents', 'lesson_page');
 
+        // Remap all the restored prevpageid and nextpageid now that we have all the pages and their mappings
+        $rs = $DB->get_recordset('lesson_pages', array('lessonid' => $this->task->get_activityid()),
+                                 '', 'id, prevpageid, nextpageid');
+        foreach ($rs as $page) {
+            $page->prevpageid = (empty($page->prevpageid)) ? 0 : $this->get_mappingid('lesson_page', $page->prevpageid);
+            $page->nextpageid = (empty($page->nextpageid)) ? 0 : $this->get_mappingid('lesson_page', $page->nextpageid);
+            $DB->update_record('lesson_pages', $page);
+        }
+        $rs->close();
+
         // TODO: somewhere at the end of the restore... when all the activities have been restored
         // TODO: we need to decode the lesson->activitylink that points to another activity in the course
         // TODO: great functionality that breaks self-contained principles, grrr