MDL-77745 core_question: Show question version in info box

question/type/questionbase.php

@@ -41,6 +41,7 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+use core_question\output\question_version_info;
 
 defined('MOODLE_INTERNAL') || die();
 
@@ -130,6 +131,9 @@ abstract class question_definition {
     /** @var int Bank entry id for the question */
     public $questionbankentryid;
 
+    /** @var ?int The latest version of the question. null if we haven't checked yet. */
+    protected $latestversion = null;
+
     /**
      * @var array of array of \core_customfield\data_controller objects indexed by fieldid for the questions custom fields.
      */
@@ -143,6 +147,21 @@ abstract class question_definition {
     public function __construct() {
     }
 
+    /**
+     * When a pending definition tries to read its latest version, fill in the latest version for all pending definitions
+     *
+     * @param string $name
+     * @return mixed
+     */
+    public function __get($name) {
+        if ($name === 'latestversion') {
+            if (isset(question_version_info::$pendingdefinitions[$this->id])) {
+                question_version_info::populate_latest_versions();
+            }
+            return $this->latestversion;
+        }
+    }
+
     /**
      * @return string the name of the question type (for example multichoice) that this
      * question is.
@@ -512,6 +531,18 @@ abstract class question_definition {
             DEBUG_DEVELOPER);
         return null;
     }
+
+    /**
+     * Set the latest version.
+     *
+     * Making $this->latestversion public would break the magic __get() behaviour above, so allow it to be set externally.
+     *
+     * @param int $latestversion
+     * @return void
+     */
+    public function set_latest_version(int $latestversion): void {
+        $this->latestversion = $latestversion;
+    }
 }