From 9a8f974a3acc590d7b62633ae557c3672ca8cbc7 Mon Sep 17 00:00:00 2001
From: Sara Arjona <sara@moodle.com>
Date: Fri, 1 Oct 2021 11:51:17 +0200
Subject: [PATCH] MDL-72720 mod: Implement enable_plugin() method

---
 admin/modules.php              | 39 ++++----------------------
 lib/classes/plugininfo/mod.php | 51 ++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 33 deletions(-)

diff --git a/admin/modules.php b/admin/modules.php
index e76a8e11a3c..5bfe9cd2477 100644
--- a/admin/modules.php
+++ b/admin/modules.php
@@ -30,42 +30,17 @@
 /// If data submitted, then process and store.
 
     if (!empty($hide) and confirm_sesskey()) {
-        if (!$module = $DB->get_record("modules", array("name"=>$hide))) {
-            print_error('moduledoesnotexist', 'error');
-        }
-        $DB->set_field("modules", "visible", "0", array("id"=>$module->id)); // Hide main module
-        // Remember the visibility status in visibleold
-        // and hide...
-        $sql = "UPDATE {course_modules}
-                   SET visibleold=visible, visible=0
-                 WHERE module=?";
-        $DB->execute($sql, array($module->id));
-        // Increment course.cacherev for courses where we just made something invisible.
-        // This will force cache rebuilding on the next request.
-        increment_revision_number('course', 'cacherev',
-                "id IN (SELECT DISTINCT course
-                                FROM {course_modules}
-                               WHERE visibleold=1 AND module=?)",
-                array($module->id));
-        core_plugin_manager::reset_caches();
+        $class = \core_plugin_manager::resolve_plugininfo_class('mod');
+        $class::enable_plugin($hide, false);
+
         admin_get_root(true, false);  // settings not required - only pages
         redirect(new moodle_url('/admin/modules.php'));
     }
 
     if (!empty($show) and confirm_sesskey()) {
-        if (!$module = $DB->get_record("modules", array("name"=>$show))) {
-            print_error('moduledoesnotexist', 'error');
-        }
-        $DB->set_field("modules", "visible", "1", array("id"=>$module->id)); // Show main module
-        $DB->set_field('course_modules', 'visible', '1', array('visibleold'=>1, 'module'=>$module->id)); // Get the previous saved visible state for the course module.
-        // Increment course.cacherev for courses where we just made something visible.
-        // This will force cache rebuilding on the next request.
-        increment_revision_number('course', 'cacherev',
-                "id IN (SELECT DISTINCT course
-                                FROM {course_modules}
-                               WHERE visible=1 AND module=?)",
-                array($module->id));
-        core_plugin_manager::reset_caches();
+        $class = \core_plugin_manager::resolve_plugininfo_class('mod');
+        $class::enable_plugin($show, true);
+
         admin_get_root(true, false);  // settings not required - only pages
         redirect(new moodle_url('/admin/modules.php'));
     }
@@ -163,5 +138,3 @@
     $table->print_html();
 
     echo $OUTPUT->footer();
-
-
diff --git a/lib/classes/plugininfo/mod.php b/lib/classes/plugininfo/mod.php
index d936fbc69eb..ce8ebccf1dd 100644
--- a/lib/classes/plugininfo/mod.php
+++ b/lib/classes/plugininfo/mod.php
@@ -40,6 +40,57 @@ class mod extends base {
         return $DB->get_records_menu('modules', array('visible'=>1), 'name ASC', 'name, name AS val');
     }
 
+    public static function enable_plugin(string $pluginname, int $enabled): bool {
+        global $DB;
+
+        if (!$module = $DB->get_record('modules', ['name' => $pluginname])) {
+            throw new \moodle_exception('moduledoesnotexist', 'error');
+        }
+
+        $haschanged = false;
+
+        // Only set visibility if it's different from the current value.
+        if ($module->visible != $enabled) {
+            // Set module visibility.
+            $DB->set_field('modules', 'visible', $enabled, ['id' => $module->id]);
+            $haschanged = true;
+
+            if ($enabled) {
+                // Revert the previous saved visible state for the course module.
+                $DB->set_field('course_modules', 'visible', '1', ['visibleold' => 1, 'module' => $module->id]);
+
+                // Increment course.cacherev for courses where we just made something visible.
+                // This will force cache rebuilding on the next request.
+                increment_revision_number('course', 'cacherev',
+                    "id IN (SELECT DISTINCT course
+                                       FROM {course_modules}
+                                      WHERE visible = 1 AND module = ?)",
+                    [$module->id]
+                );
+            } else {
+                // Remember the visibility status in visibleold and hide.
+                $sql = "UPDATE {course_modules}
+                           SET visibleold = visible, visible = 0
+                         WHERE module = ?";
+                $DB->execute($sql, [$module->id]);
+                // Increment course.cacherev for courses where we just made something invisible.
+                // This will force cache rebuilding on the next request.
+                increment_revision_number('course', 'cacherev',
+                    'id IN (SELECT DISTINCT course
+                                       FROM {course_modules}
+                                      WHERE visibleold = 1 AND module = ?)',
+                    [$module->id]
+                );
+            }
+
+            // Include this information into config changes table.
+            add_to_config_log('mod_visibility', $module->visible, $enabled, $pluginname);
+            \core_plugin_manager::reset_caches();
+        }
+
+        return $haschanged;
+    }
+
     /**
      * Magic method getter, redirects to read only values.
      *