MDL-32508 course formats: Remove key callback

This was used by course formats but now there is a standardised
'section' param

course/format/topics/lib.php

@@ -57,16 +57,6 @@ function callback_topics_definition() {
     return get_string('topic');
 }
 
-/**
- * The GET argument variable that is used to identify the section being
- * viewed by the user (if there is one)
- *
- * @return string
- */
-function callback_topics_request_key() {
-    return 'topic';
-}
-
 function callback_topics_get_section_name($course, $section) {
     // We can't add a node without any text
     if (!empty($section->name)) {

course/format/weeks/lib.php

@@ -57,16 +57,6 @@ function callback_weeks_definition() {
     return get_string('week');
 }
 
-/**
- * The GET argument variable that is used to identify the section being
- * viewed by the user (if there is one)
- *
- * @return string
- */
-function callback_weeks_request_key() {
-    return 'week';
-}
-
 /**
  * Gets the name for the provided section.
  *

lib/navigationlib.php

@@ -1766,10 +1766,9 @@ public function load_generic_course_sections(stdClass $course, navigation_node $
             $urlfunction = null;
         }
 
-        $keyfunction = 'callback_'.$courseformat.'_request_key';
         $key = 0;
-        if (defined('AJAX_SCRIPT') && AJAX_SCRIPT == '0' && function_exists($keyfunction) && $this->page->url->compare(new moodle_url('/course/view.php'), URL_MATCH_BASE)) {
-            $key = optional_param($keyfunction(), $key, PARAM_INT);
+        if (defined('AJAX_SCRIPT') && AJAX_SCRIPT == '0' && $this->page->url->compare(new moodle_url('/course/view.php'), URL_MATCH_BASE)) {
+            $key = optional_param('section', $key, PARAM_INT);
         }
 
         $navigationsections = array();