CakeRequest::referer PHP Method

    public function referer($local = false)
    {
        $ref = env('HTTP_REFERER');
        $base = Configure::read('App.fullBaseUrl') . $this->webroot;
        if (!empty($ref) && !empty($base)) {
            if ($local && strpos($ref, $base) === 0) {
                $ref = substr($ref, strlen($base));
                if (empty($ref)) {
                    $ref = '/';
                }
                if ($ref[0] !== '/') {
                    $ref = '/' . $ref;
                }
                return $ref;
            } elseif (!$local) {
                return $ref;
            }
        }
        return '/';
    }

 /**
  * beforeSave is called before a model is saved. Returning false from a beforeSave callback
  * will abort the save operation.
  *
  * @param Model $model Model using this behavior
  * @param array $options Options passed from Model::save().
  *
  * @return mixed|void
  */
 public function beforeSave(\Model $model, $options = array())
 {
     parent::beforeSave($model);
     $request = new CakeRequest();
     $data = ['blog' => urlencode(Configure::read('General.site_url')), 'user_ip' => urlencode($model->data[$model->alias]['author_ip']), 'user_agent' => urlencode($model->data[$model->alias]['agent']), 'referrer' => urlencode($request->referer()), 'permalink' => urlencode($request->referer()), 'comment_type' => urlencode('comment'), 'comment_author' => urlencode($model->data[$model->alias]['author']), 'comment_author_email' => urlencode($model->data[$model->alias]['author_email']), 'comment_author_url' => urlencode($model->data[$model->alias]['author_url']), 'comment_content' => urlencode($model->data[$model->alias]['content'])];
     if (Akismet::isSpam($data, Configure::read('Akismet.api_key'))) {
         $model->data[$model->alias]['status'] = 'spam';
     }
 }