CMS action related extension points (#9340)

* CMS action related extension points

* Refactor to use fewer extension points

* Remove explicit return type

Co-authored-by: Aaron Carlino <unclecheese@leftandmain.com>

src/Forms/FormRequestHandler.php

@@ -225,25 +225,26 @@ class FormRequestHandler extends RequestHandler
 
             // First, try a handler method on the controller (has been checked for allowed_actions above already)
             $controller = $this->form->getController();
+            $args = [$funcName, $request, $vars];
             if ($controller && $controller->hasMethod($funcName)) {
                 $controller->setRequest($request);
-                return $controller->$funcName($vars, $this->form, $request, $this);
+                return $this->invokeFormHandler($controller, ...$args);
             }
 
             // Otherwise, try a handler method on the form request handler.
             if ($this->hasMethod($funcName)) {
-                return $this->$funcName($vars, $this->form, $request, $this);
+                return $this->invokeFormHandler($this, ...$args);
             }
 
             // Otherwise, try a handler method on the form itself
             if ($this->form->hasMethod($funcName)) {
-                return $this->form->$funcName($vars, $this->form, $request, $this);
+                return $this->invokeFormHandler($this->form, ...$args);
             }
 
             // Check for inline actions
             $field = $this->checkFieldsForAction($this->form->Fields(), $funcName);
             if ($field) {
-                return $field->$funcName($vars, $this->form, $request, $this);
+                return $this->invokeFormHandler($field, ...$args);
             }
         } catch (ValidationException $e) {
             // The ValdiationResult contains all the relevant metadata
@@ -515,4 +516,20 @@ class FormRequestHandler extends RequestHandler
     {
         return $this->form->forTemplate();
     }
+
+    /**
+     * @param $subject
+     * @param string $funcName
+     * @param HTTPRequest $request
+     * @param array $vars
+     * @return mixed
+     */
+    private function invokeFormHandler($subject, string $funcName, HTTPRequest $request, array $vars)
+    {
+        $this->extend('beforeCallFormHandler', $request, $funcName, $vars, $this->form, $subject);
+        $result = $subject->$funcName($vars, $this->form, $request, $this);
+        $this->extend('afterCallFormHandler', $request, $funcName, $vars, $this->form, $subject, $result);
+
+        return $result;
+    }
 }

src/Forms/GridField/GridField.php

@@ -1133,7 +1133,11 @@ class GridField extends FormField
                             }
 
                             try {
+                                $this->extend('beforeCallActionURLHandler', $request, $action);
+
                                 $result = $component->$action($this, $request);
+
+                                $this->extend('afterCallActionURLHandler', $request, $action, $result);
                             } catch (HTTPResponse_Exception $responseException) {
                                 $result = $responseException->getResponse();
                             }