protected function determineFeedType()
    {
        $feedType = strtolower($this->getRoutedParameter('feedType', static::TYPE_JSON));

        if ($feedType == static::TYPE_JSON) {
            $this->displayResolver = static::RESOLVER_JSON;
            if (empty($this->callback))
            {
                $this->contentType = static::CONTENT_TYPE_JSON;
            }
            else
            {
                $this->contentType = static::CONTENT_TYPE_JSONP;
            }
            return;
        }

        if ($feedType == static::TYPE_XML)
        {
            $this->displayResolver = static::RESOLVER_XML;
            $this->contentType = static::CONTENT_TYPE_XML;
            return;
        }

        $this->setNotReady("Please specify a valid feed type in the parameter feedType.");
    }