framework/base/View.php
public function afterRender($viewFile, $params, &$output)
    {
        if ($this->hasEventHandlers(self::EVENT_AFTER_RENDER)) {
            $event = new ViewEvent([
                'viewFile' => $viewFile,
                'params' => $params,
                'output' => $output,
            ]);
            $this->trigger(self::EVENT_AFTER_RENDER, $event);
            $output = $event->output;
        }
    }
public function afterRender($viewFile, $params, &$output)
    {
        if ($this->hasEventHandlers(self::EVENT_AFTER_RENDER)) {
            $event = new ViewEvent([
                'viewFile' => $viewFile,
                'params' => $params,
                'output' => $output,
            ]);
            $this->trigger(self::EVENT_AFTER_RENDER, $event);
            $output = $event->output;
        }
    }
This method is invoked right after [[renderFile()]] renders a view file.
The default implementation will trigger the [[EVENT_AFTER_RENDER]] event.
If you override this method, make sure you call the parent implementation first.
@param string $viewFile the view file being rendered.
@param array $params the parameter array passed to the [[render()]] method.
@param string $output the rendering result of the view file. Updates to this parameter
will be passed back and returned by [[renderFile()]].