Magento2 : Use of echo language construct is discouraged

Question

I have my RSS feed from controller returned /displayed on frontend using echo , how do I replace echo any alternate method availabale?

MEQP1.Security.LanguageConstruct.DirectOutput

public function execute()
{
        $shopUri = $this->_storeManager->getStore()->getBaseUrl();
        $posts = $this->collectionFactory->create()->addFieldToFilter('is_active', 1);

    $this->output .= '<?xml version="1.0" encoding="UTF-8"?>
    <rss version="2.0">
        <channel>
            <title><![CDATA['.$this->myHelper->getFinalIdentifier().']]></title>
            <description>Some Title</description>
            <link>'.$shopUri.'</link>
            <webMaster>'.$this->myHelper->getStoreEmail().'</webMaster>

            <image>
                <title><![CDATA['.$this->myHelper->getStorename().']]></title>

                <link>'.$shopUri.'</link>
            </image>';
    if (isset($posts) && $posts) {
        foreach ($posts as $post) {
            $url = $post->getIdentifier();
            $blog_link =  $shopUri.$this->myHelper->getDetailIdentifier($url);

            $this->output .= '
            <item>
                <title><![CDATA['.$post->getTitle().']]></title>
                <pubDate>'.date('r', strtotime($post->getPublishDate())).'</pubDate>
                <description>';
            if ($post->getImage()) {
                $this->output .= '<![CDATA[<img src="'.$this->myHelper->resizeImage($post->getImage(), 100, 75).'" title="'.$post->getTitle().'" alt="'.$post->getTitle().'" width="120"/>]]>';
            }
            $this->output .= '<![CDATA['.$post->getShortSummary().']]></description>';
            $this->output .= '
                <link>'.str_replace('&amp;', '&', htmlspecialchars($blog_link)).'</link>
                <guid isPermaLink="true">'.str_replace('&amp;', '&', htmlspecialchars($blog_link)).'</guid>
            </item>';
        }
    }
    $this->output .= '
        </channel>
    </rss>';
    echo $this->output;
 }

Answer 1

You can use following instead of echo

public function execute() {
    $data="bdfb";
    $resultJson = $this->resultFactory->create(ResultFactory::TYPE_RAW);
    $resultJson->setContents($data);
    return $resultJson;

}

Reference