NEW Provide a standardised CMSEditLink method

src/Forms/GridField/GridFieldDetailForm.php

@@ -203,9 +203,7 @@ public function getLostRecordRedirection(GridField $gridField, HTTPRequest $requ
         }
 
         $existing = DataObject::get($list->dataClass())->byID($id);
-        if ($existing && $existing->hasMethod('CMSEditLink')) {
-            $link = $existing->CMSEditLink();
-        }
+        $link = $existing?->CMSEditLink();
 
         if ($link && $link == $request->getURL()) {
             throw new \LogicException(sprintf(

src/ORM/CMSPreviewable.php

@@ -32,9 +32,9 @@ public function PreviewLink($action = null);
     public function getMimeType();
 
     /**
-     * @return string Link to the CMS-author view. Should point to a
+     * @return string|null Link to the CMS-author view. Should point to a
      * controller subclassing {@link LeftAndMain}. Example:
      * http://mysite.com/admin/edit/6
      */
-    public function CMSEditLink();
+    public function CMSEditLink(): ?string;
 }

src/ORM/DataObject.php

@@ -2692,6 +2692,16 @@ public function getViewerTemplates($suffix = '')
         return SSViewer::get_templates_by_class(static::class, $suffix, $this->baseClass());
     }
 
+    /**
+     * Get the link for editing this record in the CMS.
+     */
+    public function CMSEditLink(): ?string
+    {
+        $link = null;
+        $this->extend('updateCMSEditLink', $link);
+        return $link;
+    }
+
     /**
      * Gets the value of a field.
      * Called by {@link __get()} and any getFieldName() methods you might create.
@@ -4143,6 +4153,7 @@ public static function enable_subclass_access()
      */
     private static $casting = [
         "Title" => 'Text',
+        'CMSEditLink' => 'Text',
     ];
 
     /**

tests/php/Forms/GridField/GridFieldDetailFormTest/Person.php

@@ -75,7 +75,7 @@ public function getCMSValidator()
         );
     }
 
-    public function CMSEditLink()
+    public function CMSEditLink(): ?string
     {
         return sprintf('my-admin/%d', $this->ID);
     }