framework/base/View.php
public function beforeRender($viewFile, $params)
    {
        $event = new ViewEvent([
            'viewFile' => $viewFile,
            'params' => $params,
        ]);
        $this->trigger(self::EVENT_BEFORE_RENDER, $event);

        return $event->isValid;
    }
public function beforeRender($viewFile, $params)
    {
        $event = new ViewEvent([
            'viewFile' => $viewFile,
            'params' => $params,
        ]);
        $this->trigger(self::EVENT_BEFORE_RENDER, $event);

        return $event->isValid;
    }
This method is invoked right before [[renderFile()]] renders a view file.
The default implementation will trigger the [[EVENT_BEFORE_RENDER]] event.
If you override this method, make sure you call the parent implementation first.
@param string $viewFile the view file to be rendered.
@param array $params the parameter array passed to the [[render()]] method.
@return bool whether to continue rendering the view file.