/**
 * Delete pages and all related data
 *
 * @param mixed $context context in which page needs to be deleted.
 * @param mixed $pageids id's of pages to be deleted
 * @param int $subwikiid id of the subwiki for which all pages should be deleted
 */
function wiki_delete_pages($context, $pageids = null, $subwikiid = null)
{
    global $DB;
    if (!empty($pageids) && is_int($pageids)) {
        $pageids = array($pageids);
    } else {
        if (!empty($subwikiid)) {
            $pageids = wiki_get_page_list($subwikiid);
        }
    }
    //If there is no pageid then return as we can't delete anything.
    if (empty($pageids)) {
        return;
    }
    /// Delete page and all it's relevent data
    foreach ($pageids as $pageid) {
        if (is_object($pageid)) {
            $pageid = $pageid->id;
        }
        //Delete page comments
        $comments = wiki_get_comments($context->id, $pageid);
        foreach ($comments as $commentid => $commentvalue) {
            wiki_delete_comment($commentid, $context, $pageid);
        }
        //Delete page tags
        $tags = tag_get_tags_array('wiki_pages', $pageid);
        foreach ($tags as $tagid => $tagvalue) {
            tag_delete_instance('wiki_pages', $pageid, $tagid);
        }
        //Delete Synonym
        wiki_delete_synonym($subwikiid, $pageid);
        //Delete all page versions
        wiki_delete_page_versions(array($pageid => array(0)));
        //Delete all page locks
        wiki_delete_locks($pageid);
        //Delete all page links
        wiki_delete_links(null, $pageid);
        //Delete page
        $params = array('id' => $pageid);
        $DB->delete_records('wiki_pages', $params);
    }
}

    private function print_overridelocks() {
        global $CFG;

        wiki_delete_locks($this->page->id, null, $this->section, true, true);

        $args = "pageid=" . $this->page->id;

        if (!empty($this->section)) {
            $args .= "&section=" . urlencode($this->section);
        }

        redirect($CFG->wwwroot . '/mod/wiki/edit.php?' . $args, get_string('overridinglocks', 'wiki'), 2);
    }

/**
 * Delete pages and all related data
 *
 * @param mixed $context context in which page needs to be deleted.
 * @param mixed $pageids id's of pages to be deleted
 * @param int $subwikiid id of the subwiki for which all pages should be deleted
 */
function wiki_delete_pages($context, $pageids = null, $subwikiid = null)
{
    global $DB, $CFG;
    if (!empty($pageids) && is_int($pageids)) {
        $pageids = array($pageids);
    } else {
        if (!empty($subwikiid)) {
            $pageids = wiki_get_page_list($subwikiid);
        }
    }
    //If there is no pageid then return as we can't delete anything.
    if (empty($pageids)) {
        return;
    }
    /// Delete page and all it's relevent data
    foreach ($pageids as $pageid) {
        if (is_object($pageid)) {
            $pageid = $pageid->id;
        }
        //Delete page comments
        $comments = wiki_get_comments($context->id, $pageid);
        foreach ($comments as $commentid => $commentvalue) {
            wiki_delete_comment($commentid, $context, $pageid);
        }
        //Delete page tags
        core_tag_tag::remove_all_item_tags('mod_wiki', 'wiki_pages', $pageid);
        //Delete Synonym
        wiki_delete_synonym($subwikiid, $pageid);
        //Delete all page versions
        wiki_delete_page_versions(array($pageid => array(0)), $context);
        //Delete all page locks
        wiki_delete_locks($pageid);
        //Delete all page links
        wiki_delete_links(null, $pageid);
        $params = array('id' => $pageid);
        // Get page before deleting.
        $page = $DB->get_record('wiki_pages', $params);
        //Delete page
        $DB->delete_records('wiki_pages', $params);
        // Trigger page_deleted event.
        $event = \mod_wiki\event\page_deleted::create(array('context' => $context, 'objectid' => $pageid, 'other' => array('subwikiid' => $subwikiid)));
        $event->add_record_snapshot('wiki_pages', $page);
        $event->trigger();
    }
}

    }
    $wikipage = new page_wiki_save($wiki, $subwiki, $cm);
    $wikipage->set_page($page);
    $wikipage->set_newcontent($newcontent);
    $wikipage->set_upload(true);
} else {
    if ($option == get_string('preview')) {
        if (!confirm_sesskey()) {
            print_error(get_string('invalidsesskey', 'wiki'));
        }
        $wikipage = new page_wiki_preview($wiki, $subwiki, $cm);
        $wikipage->set_page($page);
    } else {
        if ($option == get_string('cancel')) {
            //delete lock
            wiki_delete_locks($page->id, $USER->id, $section);
            redirect($CFG->wwwroot . '/mod/wiki/view.php?pageid=' . $pageid);
        } else {
            $wikipage = new page_wiki_edit($wiki, $subwiki, $cm);
            $wikipage->set_page($page);
            $wikipage->set_upload($option == get_string('upload', 'wiki'));
        }
    }
    if (has_capability('mod/wiki:overridelock', $context)) {
        $wikipage->set_overridelock(true);
    }
}
if ($version >= 0) {
    $wikipage->set_versionnumber($version);
}
if (!empty($section)) {

 /**
  * Edit a page contents.
  *
  * @param int $pageid The page ID.
  * @param string $content Page contents.
  * @param int $section Section to be edited.
  * @return array of warnings and page data.
  * @since Moodle 3.1
  */
 public static function edit_page($pageid, $content, $section = null)
 {
     global $USER;
     $params = self::validate_parameters(self::edit_page_parameters(), array('pageid' => $pageid, 'content' => $content, 'section' => $section));
     $warnings = array();
     // Get wiki page.
     if (!($page = wiki_get_page($params['pageid']))) {
         throw new moodle_exception('incorrectpageid', 'wiki');
     }
     // Get wiki instance.
     if (!($wiki = wiki_get_wiki_from_pageid($params['pageid']))) {
         throw new moodle_exception('incorrectwikiid', 'wiki');
     }
     // Get subwiki instance.
     if (!($subwiki = wiki_get_subwiki($page->subwikiid))) {
         throw new moodle_exception('incorrectsubwikiid', 'wiki');
     }
     // Permission validation.
     $cm = get_coursemodule_from_instance('wiki', $wiki->id, $wiki->course);
     $context = context_module::instance($cm->id);
     self::validate_context($context);
     if (!wiki_user_can_edit($subwiki)) {
         throw new moodle_exception('cannoteditpage', 'wiki');
     }
     if (wiki_is_page_section_locked($page->id, $USER->id, $params['section'])) {
         throw new moodle_exception('pageislocked', 'wiki');
     }
     // Save content.
     if (!is_null($params['section'])) {
         $version = wiki_get_current_version($page->id);
         $content = wiki_parser_proxy::get_section($version->content, $version->contentformat, $params['section'], false);
         if (!$content) {
             throw new moodle_exception('invalidsection', 'wiki');
         }
         $save = wiki_save_section($page, $params['section'], $params['content'], $USER->id);
     } else {
         $save = wiki_save_page($page, $params['content'], $USER->id);
     }
     wiki_delete_locks($page->id, $USER->id, $params['section']);
     if (!$save) {
         throw new moodle_exception('savingerror', 'wiki');
     }
     $result = array();
     $result['pageid'] = $page->id;
     $result['warnings'] = $warnings;
     return $result;
 }