rss-functions.php

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				if ( MAGPIE_DEBUG > 1) {
				debug("MagpieRSS: Cache HIT", E_USER_NOTICE);
			}
				return $rss;
			}
		}
		
		// else attempt a conditional get
		
		// setup headers
		if ( $cache_status == 'STALE' ) {
			$rss = $cache->get( $url );
			if ( $rss->etag and $rss->last_modified ) {
				$request_headers['If-None-Match'] = $rss->etag;
				$request_headers['If-Last-Modified'] = $rss->last_modified;
			}
		}
		
		$resp = _fetch_remote_file( $url, $request_headers );
		
		if (isset($resp) and $resp) {
			if ($resp->status == '304' ) {
				// we have the most current copy
				if ( MAGPIE_DEBUG > 1) {
					debug("Got 304 for $url");
				}
				// reset cache on 304 (at minutillo insistent prodding)
				$cache->set($url, $rss);
				return $rss;
			}
			elseif ( is_success( $resp->status ) ) {
				$rss = _response_to_rss( $resp );
				if ( $rss ) {
					if (MAGPIE_DEBUG > 1) {
						debug("Fetch successful");
					}
					// add object to cache
					$cache->set( $url, $rss );
					return $rss;
				}
			}
			else {
				$errormsg = "Failed to fetch $url. ";
				if ( $resp->error ) {
					# compensate for Snoopy's annoying habbit to tacking
					# on '\n'
					$http_error = substr($resp->error, 0, -2); 
					$errormsg .= "(HTTP Error: $http_error)";
				}
				else {
					$errormsg .=  "(HTTP Response: " . $resp->response_code .')';
				}
			}
		}
		else {
			$errormsg = "Unable to retrieve RSS file for unknown reasons.";
		}
		
		// else fetch failed
		
		// attempt to return cached object
		if ($rss) {
			if ( MAGPIE_DEBUG ) {
				debug("Returning STALE object for $url");
			}
			return $rss;
		}
		
		// else we totally failed
		// error( $errormsg );	
		
		return false;
		
	} // end if ( !MAGPIE_CACHE_ON ) {
} // end fetch_rss()

function _fetch_remote_file ($url, $headers = "" ) {
	// Snoopy is an HTTP client in PHP
	$client = new Snoopy();
	$client->agent = MAGPIE_USER_AGENT;
	$client->read_timeout = MAGPIE_FETCH_TIME_OUT;
	$client->use_gzip = MAGPIE_USE_GZIP;
	if (is_array($headers) ) {
		$client->rawheaders = $headers;
	}
	
	@$client->fetch($url);
	return $client;

}

function _response_to_rss ($resp) {
	$rss = new MagpieRSS( $resp->results );
	
	// if RSS parsed successfully		
	if ( $rss and !$rss->ERROR) {
		
		// find Etag, and Last-Modified
		foreach($resp->headers as $h) {
			// 2003-03-02 - Nicola Asuni (www.tecnick.com) - fixed bug "Undefined offset: 1"
			if (strpos($h, ": ")) {
				list($field, $val) = explode(": ", $h, 2);
			}
			else {
				$field = $h;
				$val = "";
			}
			
			if ( $field == 'ETag' ) {
				$rss->etag = $val;
			}
			
			if ( $field == 'Last-Modified' ) {
				$rss->last_modified = $val;
			}
		}
		
		return $rss;	
	} // else construct error message
	else {
		$errormsg = "Failed to parse RSS file.";
		
		if ($rss) {
			$errormsg .= " (" . $rss->ERROR . ")";
		}
		// error($errormsg);
		
		return false;
	} // end if ($rss and !$rss->error)
}

/*=======================================================================*\
	Function:	init
	Purpose:	setup constants with default values
				check for user overrides
\*=======================================================================*/
function init () {
	if ( defined('MAGPIE_INITALIZED') ) {
		return;
	}
	else {
		define('MAGPIE_INITALIZED', 1);
	}
	
	if ( !defined('MAGPIE_CACHE_ON') ) {
		define('MAGPIE_CACHE_ON', 1);
	}

	if ( !defined('MAGPIE_CACHE_DIR') ) {
		define('MAGPIE_CACHE_DIR', './cache');
	}

	if ( !defined('MAGPIE_CACHE_AGE') ) {
		define('MAGPIE_CACHE_AGE', 60*60); // one hour
	}

	if ( !defined('MAGPIE_CACHE_FRESH_ONLY') ) {
		define('MAGPIE_CACHE_FRESH_ONLY', 0);
	}
	
		if ( !defined('MAGPIE_DEBUG') ) {
		define('MAGPIE_DEBUG', 0);
	}

	if ( !defined('MAGPIE_USER_AGENT') ) {
		$ua = 'WordPress/' . $wp_version;
		
		if ( MAGPIE_CACHE_ON ) {
			$ua = $ua . ')';
		}
		else {
			$ua = $ua . '; No cache)';
		}
		
		define('MAGPIE_USER_AGENT', $ua);
	}
	
	if ( !defined('MAGPIE_FETCH_TIME_OUT') ) {
		define('MAGPIE_FETCH_TIME_OUT', 2);	// 2 second timeout
	}
	
	// use gzip encoding to fetch rss files if supported?
	if ( !defined('MAGPIE_USE_GZIP') ) {
		define('MAGPIE_USE_GZIP', true);	
	}
}

function is_info ($sc) { 
	return $sc >= 100 && $sc < 200; 
}

function is_success ($sc) { 
	return $sc >= 200 && $sc < 300; 
}

function is_redirect ($sc) { 
	return $sc >= 300 && $sc < 400; 
}

function is_error ($sc) { 
	return $sc >= 400 && $sc < 600; 
}

function is_client_error ($sc) { 
	return $sc >= 400 && $sc < 500; 
}

function is_server_error ($sc) { 
	return $sc >= 500 && $sc < 600; 
}

class RSSCache {
	var $BASE_CACHE = 'wp-content/cache';	// where the cache files are stored
	var $MAX_AGE	= 43200;  		// when are files stale, default twelve hours
	var $ERROR 		= '';			// accumulate error messages
	
	function RSSCache ($base='', $age='') {
		if ( $base ) {
			$this->BASE_CACHE = $base;
		}
		if ( $age ) {
			$this->MAX_AGE = $age;
		}
	
	}
	
/*=======================================================================*\
	Function:	set
	Purpose:	add an item to the cache, keyed on url
	Input:		url from wich the rss file was fetched
	Output:		true on sucess	
\*=======================================================================*/
	function set ($url, $rss) {
		global $wpdb;
		$cache_option = 'rss_' . $this->file_name( $url );
		$cache_timestamp = 'rss_' . $this->file_name( $url ) . '_ts';
		
		if ( !$wpdb->get_var("SELECT option_name FROM $wpdb->options WHERE option_name = '$cache_option'") )
			add_option($cache_option, '', '', 'no');
		if ( !$wpdb->get_var("SELECT option_name FROM $wpdb->options WHERE option_name = '$cache_timestamp'") )
			add_option($cache_timestamp, '', '', 'no');
		
		update_option($cache_option, $rss);
		update_option($cache_timestamp, time() );
		
		return $cache_option;
	}
	
/*=======================================================================*\
	Function:	get
	Purpose:	fetch an item from the cache
	Input:		url from wich the rss file was fetched
	Output:		cached object on HIT, false on MISS	
\*=======================================================================*/	
	function get ($url) {
		$this->ERROR = "";
		$cache_option = 'rss_' . $this->file_name( $url );
		
		if ( ! get_option( $cache_option ) ) {
			$this->debug( 
				"Cache doesn't contain: $url (cache option: $cache_option)"
			);
			return 0;
		}
		
		$rss = get_option( $cache_option );
		
		return $rss;
	}

/*=======================================================================*\
	Function:	check_cache
	Purpose:	check a url for membership in the cache
				and whether the object is older then MAX_AGE (ie. STALE)
	Input:		url from wich the rss file was fetched
	Output:		cached object on HIT, false on MISS	
\*=======================================================================*/		
	function check_cache ( $url ) {
		$this->ERROR = "";
		$cache_option = $this->file_name( $url );
		$cache_timestamp = 'rss_' . $this->file_name( $url ) . '_ts';

		if ( $mtime = get_option($cache_timestamp) ) {
			// find how long ago the file was added to the cache
			// and whether that is longer then MAX_AGE
			$age = time() - $mtime;
			if ( $this->MAX_AGE > $age ) {
				// object exists and is current
				return 'HIT';
			}
			else {
				// object exists but is old
				return 'STALE';
			}
		}
		else {
			// object does not exist
			return 'MISS';
		}
	}

/*=======================================================================*\
	Function:	serialize
\*=======================================================================*/		
	function serialize ( $rss ) {
		return serialize( $rss );
	}

/*=======================================================================*\
	Function:	unserialize
\*=======================================================================*/		
	function unserialize ( $data ) {
		return unserialize( $data );
	}
	
/*=======================================================================*\
	Function:	file_name
	Purpose:	map url to location in cache
	Input:		url from wich the rss file was fetched
	Output:		a file name
\*=======================================================================*/		
	function file_name ($url) {
		return md5( $url );
	}
	
/*=======================================================================*\
	Function:	error
	Purpose:	register error
\*=======================================================================*/			
	function error ($errormsg, $lvl=E_USER_WARNING) {
		// append PHP's error message if track_errors enabled
		if ( isset($php_errormsg) ) { 
			$errormsg .= " ($php_errormsg)";
		}
		$this->ERROR = $errormsg;
		if ( MAGPIE_DEBUG ) {
			trigger_error( $errormsg, $lvl);
		}
		else {
			error_log( $errormsg, 0);
		}
	}
			function debug ($debugmsg, $lvl=E_USER_NOTICE) {
		if ( MAGPIE_DEBUG ) {
			$this->error("MagpieRSS [debug] $debugmsg", $lvl);
		}
	}
}

function parse_w3cdtf ( $date_str ) {
	
	# regex to match wc3dtf
	$pat = "/(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2})(:(\d{2}))?(?:([-+])(\d{2}):?(\d{2})|(Z))?/";
	
	if ( preg_match( $pat, $date_str, $match ) ) {
		list( $year, $month, $day, $hours, $minutes, $seconds) = 
			array( $match[1], $match[2], $match[3], $match[4], $match[5], $match[6]);
		
		# calc epoch for current date assuming GMT
		$epoch = gmmktime( $hours, $minutes, $seconds, $month, $day, $year);
		
		$offset = 0;
		if ( $match[10] == 'Z' ) {
			# zulu time, aka GMT
		}
		else {
			list( $tz_mod, $tz_hour, $tz_min ) =
				array( $match[8], $match[9], $match[10]);
			
			# zero out the variables
			if ( ! $tz_hour ) { $tz_hour = 0; }
			if ( ! $tz_min ) { $tz_min = 0; }
		
			$offset_secs = (($tz_hour*60)+$tz_min)*60;
			
			# is timezone ahead of GMT?  then subtract offset
			#
			if ( $tz_mod == '+' ) {
				$offset_secs = $offset_secs * -1;
			}
			
			$offset = $offset_secs;	
		}
		$epoch = $epoch + $offset;
		return $epoch;
	}
	else {
		return -1;
	}
	}
function wp_rss ($url, $num) {
	//ini_set("display_errors", false); uncomment to suppress php errors thrown if the feed is not returned.
	$num_items = $num;
	$rss = fetch_rss($url);
		if ( $rss ) {
			echo "<ul>";
			$rss->items = array_slice($rss->items, 0, $num_items);
				foreach ($rss->items as $item ) {
					echo "<li>\n";
					echo "<a href='$item[link]' title='$item[description]'>";
					echo htmlentities($item['title']);
					echo "</a><br />\n";
					echo "</li>\n";
				}		
			echo "</ul>";
	}
		else {
			echo "an error has occured the feed is probably down, try again later.";
	}
}

function get_rss ($uri, $num = 5) { // Like get posts, but for RSS
	$rss = fetch_rss($url);
	if ( $rss ) {
		$rss->items = array_slice($rss->items, 0, $num_items);
		foreach ($rss->items as $item ) {
			echo "<li>\n";
			echo "<a href='$item[link]' title='$item[description]'>";
			echo htmlentities($item['title']);
			echo "</a><br />\n";
			echo "</li>\n";
		}
		return $posts;
	} else {
		return false;
	}
}
?>