如何从我的控制器加载opencart中的视图

Question

in my controller i have done something like this

   $this->data['first_name']= $this->request->post['first_name'];

now i want to load view

i have done something like this

    if (file_exists(DIR_TEMPLATE . $this->config->get('config_template') . '/template/information/considerForm.tpl')) {
                $this->template = $this->config->get('config_template') . '/template/information/considerForm.tpl';
            } else {
                $this->template = 'default/template/information/considerForm.tpl';
            }

            $this->children = array(  
                'common/column_left',
                'common/column_right',
                'common/content_top',
                'common/content_bottom',
                'common/footer',
                'common/header'
            );

            $this->response->setOutput($this->render());

and in tpl file

iam simple doing this

   <php echo $first_name; ?>

but it is showing me blank page. am i loading the view correctly??