Caching Tweets with tmhOAuth

tmoauth-caching.php

<?php
class Tweets
{

	/**
	 * Cached results as key => value array
	 */
	private static $cache = array();


	/**
	 * Cached file directory
	 */
	private static $cacheDir = '/cache/';


	/**
	 * Cache get
	 * @param string $name The name of a stored value
	 * @throws Exception If cached item not found
	 * @return any The cached value
	 */
	private static function cacheGet($name)
	{
		if ( array_key_exists($name, self::$cache) ) // undefined indexes do not throw an exception =S
		{
			return self::$cache[$name];
		}
		else
		{
			throw new Exception('notfound');
		}
	}


	/**
	 * Cache set
	 * @param string $name Name of cached value
	 * @param any $value Value to cache
	 * @return any Returns the given value
	 */
	private static function cacheSet($name, $value)
	{
		return self::$cache[$name] = $value;
	}


	/**
	 * File cache path
	 * @param string $file File name
	 * @return string Fully qualified file path
	 */
	private static function fileCachePath($file)
	{
		return dirname( __FILE__ ) . self::$cacheDir . md5($file) . '.cache';
	}


	/**
	 * File get
	 * @description Get cache file from file system
	 * @param string $file File name of cached value
	 * @param integer $expires Time to store cached file. Set to zero to get file regardless of last cached time.
	 * @throws Exception If cached item not found
	 * @throws Exception If cache exists but has expired
	 * @return any The cached value
	 */
	private static function fileGet($file, $expires = 15)
	{
		$file = self::fileCachePath($file);

		if ( ! file_exists( $file ) )
		{
			throw new Exception('notfound');
		}
		else
		{
			if ( ! $expires || time() - filemtime($file) < $expires * 60 )
			{
				return unserialize( file_get_contents($file) );
			}
			else
			{
				throw new Exception('expired');
			}
		}
	}


	/**
	 * File set
	 * @param string $file File name of cached value
	 * @param any $value Value to cache
	 * @return any Returns the given value
	 */
	private static function fileSet($file, $value)
	{
		$file	= self::fileCachePath($file);
		$cache	= fopen($file, 'w');
		$write	= fwrite($cache, serialize($value) );
		fclose($cache);

		return $value;
	}



	/**
	 * Get latest tweets
	 * @param string $user Twitter Screen name
	 * @param integer $number Number of tweets to get
	 * @param integer $expire Time in minutes to cache result
	 * @return array Latest tweets
	 */
	public static function tweets($user, $number = 10, $expire = 15)
	{
		$tweets = array();
		$file = $user . '_' . $number;

		try
		{
			$tweets = self::fileGet($file, $expire);
		}
		catch(Exception $e)
		{
			require_once 'lib/tmhOAuth/tmhOAuth.php';

			// Init OAuth
			$tmhOAuth = new tmhOAuth( array(
				'consumer_key'		=> TWITTER_CONSUMER_KEY,
				'consumer_secret'	=> TWITTER_CONSUMER_SECRET,
				'user_token'		=> TWITTER_USER_TOKEN,
				'user_secret'		=> TWITTER_USER_SECRET
			) );

			$method = "https://api.twitter.com/1/statuses/user_timeline.json";

			$params = array(
				'screen_name'		=> $user,
				'count'			=> $number,
				'include_rts'		=> false,
				'include_entities'	=> true
			);

			// Parse result if successful
			if ( $tmhOAuth->request('GET', $method, $params) == 200 )
			{
				$tweets = json_decode($tmhOAuth->response['response'], true);

				// Save to file
				if ( count($tweets) )
				{
					self::fileSet($file, $tweets);
				}
			}

			// Retrieve expired cache if it exists when request fails
			else if ( $e->getMessage() == 'expired' )
			{
				try
				{
					self::fileGet($file, 0);
				}
				catch(Exception $e){}
			}
		}

		return $tweets;
	}


	/**
	 * Tweet entify
	 * @description Enables all tweet features as per API requirements
	 * @param object $tweet JSON decoded tweet object
	 * @return string The tweet content with entities replaced
	 */
	public static function tweet_entify($tweet)
	{
		try
		{
			$tmhUtil = self::cacheGet('entify_tweet');
		}
		catch(Exception $e)
		{
			require_once 'lib/tmhOAuth/tmhUtilities.php';
			$tmhUtil = self::cacheSet('entify_tweet', new tmhUtilities() );
		}

		return $tmhUtil->entify($tweet);
	}


	/**
	 * Tweet link
	 * @description Creates date link to original tweet
	 * @param object $tweet JSON decoded tweet object
	 * @param string $dateFormat PHP date format
	 * @return string HTML string
	 */
	public static function tweet_permalink($tweet, $dateFormat = 'H:ia d.m.Y')
	{
		$href = 'http://twitter.com/' . $tweet['user']['screen_name'] . '/status/' . $tweet['id_str'];
		return '<a href="' . $href . '">' . date($dateFormat, strtotime($tweet['created_at']) ) . '</a>';
	}

}