MDL-68189 course: Section name change should display in DD menu

Before this patch if a section was renamed inline the old name was
still displayed in the keyboard drag and drop menu until the page
was refreshed.

This change ensures that the two places that section names were not
updated in get changed after an inline update to the name.

course/amd/src/sectionlistener.js

@@ -0,0 +1,56 @@
+// 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/>.
+
+/**
+ * Define listeners related to sections.
+ *
+ * @module     core_course/sectionlistener
+ * @package    core_course
+ * @copyright  2020 University of Nottingham
+ * @author     Neill Magill <neill.magill@nottingham.ac.uk>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+define(['jquery'], function($) {
+    /**
+     * Processes an updated event.
+     *
+     * We only want to handle events related to a section, and not activities.
+     *
+     * @param {Event} e The updated event
+     */
+    var processUpdatedEvent = function(e) {
+        var editable = $(this);
+        if (editable.data('itemtype') === 'sectionname') {
+            var config = M.course.format.get_config();
+            // A section name got updated.
+            var section = editable.closest('.' + config.section_class);
+            updateSectionName(section, e.ajaxreturn.value);
+        }
+        // Ignore other types of inplace updates, for example activity name changes.
+    };
+
+    /**
+     * Updates the name of the section in places outside of the inplace editable field.
+     *
+     * @param {jQuery} section The section that was updated.
+     * @param {String} newname The new name for the section.
+     */
+    var updateSectionName = function(section, newname) {
+        section.attr('aria-label', newname);
+        section.find('.hidden.sectionname').text(newname);
+    };
+
+    $('body').on('updated', '.inplaceeditable', processUpdatedEvent);
+});

course/format/topics/format.php

@@ -59,3 +59,4 @@
 
 // Include course format js module
 $PAGE->requires->js('/course/format/topics/format.js');
+$PAGE->requires->js_call_amd('core_course/sectionlistener');

course/format/weeks/format.php

@@ -50,3 +50,4 @@
 }
 
 $PAGE->requires->js('/course/format/weeks/format.js');
+$PAGE->requires->js_call_amd('core_course/sectionlistener');