Generate RSS feed from Google Plus public feed for using it as IFTTT source, or whatever ...

gpfeed.php

<?php
  function getSslPage($url) {
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
    curl_setopt($ch, CURLOPT_HEADER, false);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_REFERER, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
    $result = curl_exec($ch);
    curl_close($ch);
    return $result;
  }
  
  function startsWith($haystack, $needle) {
    return $needle === "" || strrpos($haystack, $needle, -strlen($haystack)) !== false;
  }

  $api_key = '.. api key ..';
  $user_id = '.. user id ..';
  $activity_feed = json_decode(getSslPage("https://www.googleapis.com/plus/v1/people/$user_id/activities/public?fields=items(object(attachments(content%2CdisplayName%2Curl)%2Ccontent)%2Cpublished%2Curl)%2Ctitle%2Cupdated&key=$api_key"));
  header('Content-Type: text/xml;charset=UTF-8');
?>
<rss xmlns:content="http://purl.org/rss/1.0/modules/content/" version="2.0">
<channel>
  <title>Google+ Feed</title>
  <description>Laszlo Fazekas G+ feed</description>
  <link>https://plus.google.com/+LaszloFazekas/posts</link>
  <?php foreach($activity_feed->items as $item): ?>
  <item>
    <?php if(startsWith($item->object->content, '<a ')): // link only ?>
    
    <title><![CDATA[<?php 
      if(isset($item->object->attachments))
	echo $item->object->attachments[0]->displayName;
    ?>]]></title>
    <link><?php echo $item->url; ?></link>
    <guid><?php echo $item->url; ?></guid>
    <description><![CDATA[<?php
      if(isset($item->object->attachments)) {
	  if($item->object->attachments[0]->content)
	    echo $item->object->attachments[0]->content;
	  else
	    echo $item->object->content;
      }    
    ?>]]></description>    
    
    <?php else: ?>

    <title></title>    
    <link><?php echo $item->url; ?></link>
    <guid><?php echo $item->url; ?></guid>
    <description><![CDATA[<?php
	echo $item->object->content;
    ?>]]></description>
    <?php endif; ?>    
    <pubDate><?php echo gmdate(DATE_RFC822, strtotime($item->published)); ?></pubDate>
  </item><?php endforeach; ?>
</channel>
</rss>