Using the Twitter API, Cache Your 'Tweets' in PHP (TwitterCacher)

WARNING:

Before you spend any of your time playing with this code, you should know that Twitter plans to stop supporting HTTP Basic Authentication on June 30, 2010.  This means that starting on June 30th, the code discussed here in this blog post will stop working.  To use Twitter's API after June 30th, your application must support OAuth.  TwitterCacher does not support OAuth and I have no plans to make it OAuth compatible.  That said, you will probably find this OAuth compatible Twitter PHP library much more useful. You might also find this writeup on Using one access token with OAuth useful.


I spent a few cycles this afternoon integrating my Twitter timeline with my Movable Type blogging software.  Surprisingly, things worked out great with no issues in the first version.  The Twitter API is a well-written REST service that made it incredibly easy to combine my lifestream with my Tweets.  BTW, I hate the word "Tweet" but that's the terminology everyone in Twitter land seems use so I will too.

To start, I snagged the php-twitter library from Google Code.  The only php-twitter functions I really cared about were process() and userTimeline(), which use libcurl to read your Tweets in JSON or XML format.  Once I had the code I wanted, I created my own PHP class named TwitterCacher to handle all of the API calls and response caching.  The idea behind TwitterCacher is to work around a rate limiting problem of the Twitter API.  Twitter limits the number of API requests you can make in an hour or so, so if you use the Twitter API you have to be conscious of this limitation (otherwise, Twitter will blacklist you).  As a result, the developer using the Twitter API has to implement some type of caching mechanism to prevent hitting Twitter too often.  To solve this caching issue, my TwitterCacher saves the JSON or XML response from the Twitter API to a flat-file on your web-server.

<?php

require_once("JSON.php");
require_once("TwitterCacher.php");

$twEmail = "you@example.com";
$twPass = "password";

$json = new Services_JSON();
$tc = new TwitterCacher($twEmail,$twPass);

// I do this just to be a nice guy. So Twitter knows who we are.
$tc->setUserAgent("Mozilla/5.0 (compatible; TwitterCacher/1.0;)");

// Read the timeline from the cache, or from Twitter.
$timeline = $json->decode( $tc->getUserTimeline() );

foreach( $timeline as $tweet ) {

  // Get the Tweet itself.
  $text = $tweet->text;

  // Twitter uses GMT+0 but I convert it to my local time.
  $date = date('M j, Y @ h:i A', strtotime($tweet->created_at));

  echo $text . "<br />" . $date . "<hr />";

}

?>