diff --git a/mod/wiki/lib.php b/mod/wiki/lib.php
index c851baef576..49a2115f632 100644
--- a/mod/wiki/lib.php
+++ b/mod/wiki/lib.php
@@ -473,80 +473,76 @@ function wiki_search_form($cm, $search = '', $subwiki = null) {
     return $OUTPUT->render_from_template('core/search_input', $data);
 }
 
-function wiki_extend_navigation(navigation_node $navref, $course, $module, $cm) {
-    global $CFG, $PAGE, $USER;
+/**
+ * Extends the global navigation tree by adding wiki nodes if there is a relevant content
+ *
+ * This can be called by an AJAX request so do not rely on $PAGE as it might not be set up properly.
+ *
+ * @param navigation_node $navref An object representing the navigation tree node of the workshop module instance
+ * @param stdClass $course the course object
+ * @param stdClass $instance the activity record object
+ * @param cm_info $cm the course module object
+ */
+function wiki_extend_navigation(navigation_node $navref, stdClass $course, stdClass $instance, cm_info $cm) {
+    global $CFG, $USER;
 
     require_once($CFG->dirroot . '/mod/wiki/locallib.php');
 
     $context = context_module::instance($cm->id);
-    $url = $PAGE->url;
-    $userid = 0;
-    if ($module->wikimode == 'individual') {
-        $userid = $USER->id;
-    }
+    $userid = ($instance->wikimode == 'individual') ? $USER->id : 0;
+    $gid = groups_get_activity_group($cm) ?: 0;
 
-    if (!$wiki = wiki_get_wiki($cm->instance)) {
-        return false;
-    }
-
-    if (!$gid = groups_get_activity_group($cm)) {
-        $gid = 0;
-    }
     if (!$subwiki = wiki_get_subwiki_by_group($cm->instance, $gid, $userid)) {
-        return null;
-    } else {
-        $swid = $subwiki->id;
+        return;
     }
 
-    $pageid = $url->param('pageid');
-    $cmid = $url->param('id');
-    if (empty($pageid) && !empty($cmid)) {
+    $pageid = optional_param('pageid', null, PARAM_INT);
+    if (empty($pageid)) {
         // wiki main page
-        $page = wiki_get_page_by_title($swid, $wiki->firstpagetitle);
+        $page = wiki_get_page_by_title($subwiki->id, $instance->firstpagetitle);
         $pageid = $page->id;
     }
 
     if (wiki_can_create_pages($context)) {
-        $link = new moodle_url('/mod/wiki/create.php', array('action' => 'new', 'swid' => $swid));
-        $node = $navref->add(get_string('newpage', 'wiki'), $link, navigation_node::TYPE_SETTING);
+        $link = new moodle_url('/mod/wiki/create.php', ['action' => 'new', 'swid' => $subwiki->id]);
+        $navref->add(get_string('newpage', 'wiki'), $link, navigation_node::TYPE_SETTING);
     }
 
-    if (is_numeric($pageid)) {
+    if (empty($pageid)) {
+        return;
+    }
 
-        if (has_capability('mod/wiki:viewpage', $context)) {
-            $link = new moodle_url('/mod/wiki/view.php', array('pageid' => $pageid));
-            $node = $navref->add(get_string('view', 'wiki'), $link, navigation_node::TYPE_SETTING);
-        }
+    $canviewpage = has_capability('mod/wiki:viewpage', $context);
 
-        if (wiki_user_can_edit($subwiki)) {
-            $link = new moodle_url('/mod/wiki/edit.php', array('pageid' => $pageid));
-            $node = $navref->add(get_string('edit', 'wiki'), $link, navigation_node::TYPE_SETTING);
-        }
+    if ($canviewpage) {
+        $link = new moodle_url('/mod/wiki/view.php', ['pageid' => $pageid]);
+        $navref->add(get_string('view', 'wiki'), $link, navigation_node::TYPE_SETTING);
+    }
 
-        if (has_capability('mod/wiki:viewcomment', $context)) {
-            $link = new moodle_url('/mod/wiki/comments.php', array('pageid' => $pageid));
-            $node = $navref->add(get_string('comments', 'wiki'), $link, navigation_node::TYPE_SETTING);
-        }
+    if (wiki_user_can_edit($subwiki)) {
+        $link = new moodle_url('/mod/wiki/edit.php', ['pageid' => $pageid]);
+        $navref->add(get_string('edit', 'wiki'), $link, navigation_node::TYPE_SETTING);
+    }
 
-        if (has_capability('mod/wiki:viewpage', $context)) {
-            $link = new moodle_url('/mod/wiki/history.php', array('pageid' => $pageid));
-            $node = $navref->add(get_string('history', 'wiki'), $link, navigation_node::TYPE_SETTING);
-        }
+    if (has_capability('mod/wiki:viewcomment', $context)) {
+        $link = new moodle_url('/mod/wiki/comments.php', ['pageid' => $pageid]);
+        $navref->add(get_string('comments', 'wiki'), $link, navigation_node::TYPE_SETTING);
+    }
 
-        if (has_capability('mod/wiki:viewpage', $context)) {
-            $link = new moodle_url('/mod/wiki/map.php', array('pageid' => $pageid));
-            $node = $navref->add(get_string('map', 'wiki'), $link, navigation_node::TYPE_SETTING);
-        }
+    if ($canviewpage) {
+        $link = new moodle_url('/mod/wiki/history.php', ['pageid' => $pageid]);
+        $navref->add(get_string('history', 'wiki'), $link, navigation_node::TYPE_SETTING);
 
-        if (has_capability('mod/wiki:viewpage', $context)) {
-            $link = new moodle_url('/mod/wiki/files.php', array('pageid' => $pageid));
-            $node = $navref->add(get_string('files', 'wiki'), $link, navigation_node::TYPE_SETTING);
-        }
+        $link = new moodle_url('/mod/wiki/map.php', ['pageid' => $pageid]);
+        $navref->add(get_string('map', 'wiki'), $link, navigation_node::TYPE_SETTING);
 
-        if (has_capability('mod/wiki:managewiki', $context)) {
-            $link = new moodle_url('/mod/wiki/admin.php', array('pageid' => $pageid));
-            $node = $navref->add(get_string('admin', 'wiki'), $link, navigation_node::TYPE_SETTING);
-        }
+        $link = new moodle_url('/mod/wiki/files.php', ['pageid' => $pageid]);
+        $navref->add(get_string('files', 'wiki'), $link, navigation_node::TYPE_SETTING);
+    }
+
+    if (has_capability('mod/wiki:managewiki', $context)) {
+        $link = new moodle_url('/mod/wiki/admin.php', ['pageid' => $pageid]);
+        $navref->add(get_string('admin', 'wiki'), $link, navigation_node::TYPE_SETTING);
     }
 }
 /**