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It's taken me a while to warm to Twitter. I created the Quicklinks category on my blog for sharing things that didn't warrant a full post, but even that's too much effort sometimes—especially if it's just sharing a link. You might argue that's what bookmarking services like Digg and Delicious are for, but even then it's a multistep process. I've only recently become aware of just how well suited the Twitter API is to sharing links or updating your status message to multiple services with minimal effort. This post shares some PHP code to integrate your tweets within your WordPress blog, and code to simplify getting your WordPress posts into other people's tweets.

The interconnectedness of tweeting

A few examples:

• I use the Twitter updater plug-in to notify Twitter of new posts on my WordPress blog.
• Darkslide on my iPhone can post a Flickr image link via the iPhone Twitterrific app.
• Most of my links are discovered in my preferred RSS reader NetNewsWire, which can send these to desktop Twitterrific (News menu).
• The Twitter app for Facebook will update your Facebook status using your tweets.
• Twitter offer an RSS feed which can be used in conjunction with the SimplePie PHP library to bring tweets to your WordPress blog.

This last example is the focus of this post. I will assume that you have already downloaded and correctly installed SimplePie for WordPress from here.

A SimplePie template for Twitter

Create a text file called tweets.tmpl containing the following:

<div class="simplepie tweets">
	{IF_ERROR_BEGIN}<p class="error">{ERROR_MESSAGE}</p>{IF_ERROR_END}
		{ITEM_LOOP_BEGIN}
		<p><span class="twit_date">{ITEM_DATE_UTC}</span><br />{ITEM_DESCRIPTION}<br /><a href="{ITEM_PERMALINK}">#</a></p>
		{ITEM_LOOP_END}
</div>

Upload this file to the following directory on your server:

/wp-content/plugins/simplepie-plugin-for-wordpress/templates/

Now for a little post-processing

Every tweet will be prefixed with your Twitter username which is a bit redundant, so you might want to strip that out. Credit to Ben Griffiths for this know-how. Create a text file called twit_strip.php containing the following (be sure to replace 'bioneural:' with your own username):

<?php

/**
 * STRIP USERNAME FROM TWITTER FEED
 *
 * This will strip out 'bioneural:' from {ITEM_DESCRIPTION}.
 *
 * If you don't want to do anything to the content, simply remove the function.
 */

// We MUST keep this classname.
class SimplePie_PostProcess
{
	// Function name MUST be the same as the template tag we're processing, all lowercase, and MUST accept a single string parameter.
	function item_description($s) {
		$s = str_replace("bioneural: ", "", $s);
		return $s;
	}
}

?>

Upload this file to the following directory on your server:

/wp-content/plugins/simplepie-plugin-for-wordpress/processing/

Resolving a Twitter feed bug

As noted here there is an unresolved bug that will cause a "There are no items in this feed." message to appear:

Twitter feeds are just fine the first time they're loaded and cached, but are missing some/all items when the cache expires and SimplePie tries to re-fetch the feed.

To counter this open simplepie.inc from the following directory:

/wp-content/plugins/simplepie-core/

Comment out lines 1583–86 (in version 1.1.1) like so:

// if (isset($this->data['headers']['last-modified']))
// {
// 	$headers['if-modified-since'] = $this->data['headers']['last-modified'];
// }

Displaying your latest tweets

I pasted this into the sidebar.php file of my WordPress theme:

<?php /* Latest tweets */ if ((function_exists('SimplePieWP')) and is_page("contact")) { ?>
<div class="sb-tweets"><h4>Latest tweets</h4>
	<a href="http://twitter.com/bioneural" title="bioneural's profile on Twitter" class="feedlink"><img src="<?php bloginfo('template_directory'); ?>/styles/bioneural/twitter.png" alt="Twitter" style="margin-right: 20px;" /></a>
	<span class="metalink"><a href="http://twitter.com/statuses/user_timeline/15629885.rss" title="Web feed for latest tweets by bioneural" class="feedlink"><img src="<?php bloginfo('template_directory'); ?>/styles/bioneural/twit-feed-16px.png" alt="Feed" /></a></span>
	<?php echo SimplePieWP(array('http://twitter.com/statuses/user_timeline/15629885.rss'), array('items' => 3, 'template' => tweets, 'processing' => twit_strip)); ?>
	<p class="simple-credit">Do it with <a href="http://simplepie.org" rel="external">Simplepie</a>
</div>
<?php } ?>

The first PHP block above just makes sure the SimplePie for WordPress plug-in is active and that the "Latest tweets" div will appear only on the "Contacts" page of my WordPress installation.

The second PHP block specifies the Twitter feed you want to use (presumably your own!) and in this case that we want to display 3 feed items using the "tweets" template (tweets.tmpl) and "twit_strip" (twit_strip.php) post-processing instructions we created above.

Tip: If you still see a "There are no items in this feed." message, try adding 'set_timeout' => 60 to the above array to increase the timeout interval (too short an interval may cause the feed not to be cached).

With appropriate styling in your CSS file you should end up with something like this:

All being well there is a "live" version here.

Your post in their tweets

We don't need SimplePie for this bit, just generic PHP. I based my code on a clever recipe from Jean-Baptiste Jung that generates a TinyURL in place of the default character-consuming permalink.

Firstly I added the following function to my theme's functions.php file, using the cURL alternative to file_get_contents():

// Create TinyURL for post to Twitter
function getTinyUrl($url) {
	$ch = curl_init();
	$timeout = 5;
	curl_setopt ($ch, CURLOPT_URL, 'http://tinyurl.com/api-create.php?url='.$url);
	curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
	curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
	$tinyurl = curl_exec($ch);
	curl_close($ch);
	return $tinyurl;
}

In the WordPress loop (theloop.php in the K2 theme) I added the following code to the "Actions" area at the foot of each post:

<span class="socialtwit"><a href="http://twitter.com/home?status=Reading%20'<?php _e(urlencode(the_title_attribute('echo=0'))); ?>'%20@%20<?php $turl = getTinyUrl(get_permalink($post->ID)); echo $turl ?>" title="Tweet this"><img src="http://www.bioneural.net/wp-content/themes/k2bn/styles/bioneural/twitter.png" alt="Twitter" /></a> Twitter</span>

All the reader sees is a Twitter icon:

This icon is linked to a properly encoded URL such as this:

http://twitter.com/home?status=Reading%20'Desktop+refits+with+GeekTool+and+friends'%20@%20http://tinyurl.com/cs54je

With no effort at all the reader can tweet your post complete with a "Reading" prefix, title, and compact URL:

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