MDL-72050 filelib: Add function for deleting draftarea

lib/filelib.php

@@ -1313,6 +1313,19 @@ function file_save_draft_area_files($draftitemid, $contextid, $component, $filea
     }
 }
 
+/**
+ * Clear a draft area.
+ *
+ * @param int $draftitemid Id of the draft area to clear.
+ * @return boolean success
+ */
+function file_clear_draft_area(int $draftitemid): bool {
+    global $USER;
+    $fs = get_file_storage();
+    $usercontext = context_user::instance($USER->id);
+    return $fs->delete_area_files($usercontext->id, 'user', 'draft', $draftitemid);
+}
+
 /**
  * Convert the draft file area URLs in some content to @@PLUGINFILE@@ tokens
  * ready to be saved in the database. Normally, this is done automatically by

lib/upgrade.txt

@@ -25,6 +25,9 @@ completed modules to the DBMS improving the performance of the method.
   user has been redirected to the expected location.
   e.g. `And the url should match "/mod/forum/view\.php\?id=[0-9]+"`
 
+* A new function `file_clear_draft_area()` has been added to delete the files in a draft area.
+  For more information see [MDL-72050](https://tracker.moodle.org/browse/MDL-72050)
+
 === 4.4.5 ===
 
 * All uses of the following PHPUnit methods have been removed as these methods are deprecated upstream without direct replacement: