root/tags/2.0/wp-includes/rss-functions.php

<?php
/*
 * Project:     MagpieRSS: a simple RSS integration tool
 * File:        A compiled file for RSS syndication
 * Author:      Kellan Elliott-McCrea <kellan@protest.net>
 * Version:        0.51
 * License:        GPL
 */

define('RSS', 'RSS');
define('ATOM', 'Atom');
define('MAGPIE_USER_AGENT', 'WordPress/' . $wp_version);

class MagpieRSS { 
    var $parser;
    var $current_item    = array();    // item currently being parsed
    var $items            = array();    // collection of parsed items
    var $channel        = array();    // hash of channel fields
    var $textinput        = array();
    var $image            = array();
    var $feed_type;
    var $feed_version;

    // parser variables
    var $stack                = array(); // parser stack
    var $inchannel            = false;
    var $initem             = false;
    var $incontent            = false; // if in Atom <content mode="xml"> field 
    var $intextinput        = false;
    var $inimage             = false;
    var $current_field        = '';
    var $current_namespace    = false;
    
    //var $ERROR = "";
    
    var $_CONTENT_CONSTRUCTS = array('content', 'summary', 'info', 'title', 'tagline', 'copyright');

    function MagpieRSS ($source) {
        
        # if PHP xml isn't compiled in, die
        #
        if ( !function_exists('xml_parser_create') )
            trigger_error( "Failed to load PHP's XML Extension. http://www.php.net/manual/en/ref.xml.php" );
        
        $parser = @xml_parser_create();
        
        if ( !is_resource($parser) )
            trigger_error( "Failed to create an instance of PHP's XML parser. http://www.php.net/manual/en/ref.xml.php");

        
        $this->parser = $parser;
        
        # pass in parser, and a reference to this object
        # setup handlers
        #
        xml_set_object( $this->parser, $this );
        xml_set_element_handler($this->parser, 
                'feed_start_element', 'feed_end_element' );
                        
        xml_set_character_data_handler( $this->parser, 'feed_cdata' ); 
    
        $status = xml_parse( $this->parser, $source );
        
        if (! $status ) {
            $errorcode = xml_get_error_code( $this->parser );
            if ( $errorcode != XML_ERROR_NONE ) {
                $xml_error = xml_error_string( $errorcode );
                $error_line = xml_get_current_line_number($this->parser);
                $error_col = xml_get_current_column_number($this->parser);
                $errormsg = "$xml_error at line $error_line, column $error_col";

                $this->error( $errormsg );
            }
        }
        
        xml_parser_free( $this->parser );

        $this->normalize();
    }
    
    function feed_start_element($p, $element, &$attrs) {
        $el = $element = strtolower($element);
        $attrs = array_change_key_case($attrs, CASE_LOWER);
        
        // check for a namespace, and split if found
        $ns    = false;
        if ( strpos( $element, ':' ) ) {
            list($ns, $el) = split( ':', $element, 2); 
        }
        if ( $ns and $ns != 'rdf' ) {
            $this->current_namespace = $ns;
        }
            
        # if feed type isn't set, then this is first element of feed
        # identify feed from root element
        #
        if (!isset($this->feed_type) ) {
            if ( $el == 'rdf' ) {
                $this->feed_type = RSS;
                $this->feed_version = '1.0';
            }
            elseif ( $el == 'rss' ) {
                $this->feed_type = RSS;
                $this->feed_version = $attrs['version'];
            }
            elseif ( $el == 'feed' ) {
                $this->feed_type = ATOM;
                $this->feed_version = $attrs['version'];
                $this->inchannel = true;
            }
            return;
        }
    
        if ( $el == 'channel' ) 
        {
            $this->inchannel = true;
        }
        elseif ($el == 'item' or $el == 'entry' ) 
        {
            $this->initem = true;
            if ( isset($attrs['rdf:about']) ) {
                $this->current_item['about'] = $attrs['rdf:about'];    
            }
        }
        
        // if we're in the default namespace of an RSS feed,
        //  record textinput or image fields
        elseif ( 
            $this->feed_type == RSS and 
            $this->current_namespace == '' and 
            $el == 'textinput' ) 
        {
            $this->intextinput = true;
        }
        
        elseif (
            $this->feed_type == RSS and 
            $this->current_namespace == '' and 
            $el == 'image' ) 
        {
            $this->inimage = true;
        }
        
        # handle atom content constructs
        elseif ( $this->feed_type == ATOM and in_array($el, $this->_CONTENT_CONSTRUCTS) )
        {
            // avoid clashing w/ RSS mod_content
            if ($el == 'content' ) {
                $el = 'atom_content';
            }
            
            $this->incontent = $el;
            
            
        }
        
        // if inside an Atom content construct (e.g. content or summary) field treat tags as text
        elseif ($this->feed_type == ATOM and $this->incontent ) 
        {
            // if tags are inlined, then flatten
            $attrs_str = join(' ', 
                    array_map('map_attrs', 
                    array_keys($attrs), 
                    array_values($attrs) ) );
            
            $this->append_content( "<$element $attrs_str>"  );
                    
            array_unshift( $this->stack, $el );
        }
        
        // Atom support many links per containging element.
        // Magpie treats link elements of type rel='alternate'
        // as being equivalent to RSS's simple link element.
        //
        elseif ($this->feed_type == ATOM and $el == 'link' ) 
        {
            if ( isset($attrs['rel']) and $attrs['rel'] == 'alternate' ) 
            {
                $link_el = 'link';
            }
            else {
                $link_el = 'link_' . $attrs['rel'];
            }
            
            $this->append($link_el, $attrs['href']);
        }
        // set stack[0] to current element
        else {
            array_unshift($this->stack, $el);
        }
    }
    

    
    function feed_cdata ($p, $text) {
        
        if ($this->feed_type == ATOM and $this->incontent) 
        {
            $this->append_content( $text );
        }
        else {
            $current_el = join('_', array_reverse($this->stack));
            $this->append($current_el, $text);
        }
    }
    
    function feed_end_element ($p, $el) {
        $el = strtolower($el);
        
        if ( $el == 'item' or $el == 'entry' ) 
        {
            $this->items[] = $this->current_item;
            $this->current_item = array();
            $this->initem = false;
        }
        elseif ($this->feed_type == RSS and $this->current_namespace == '' and $el == 'textinput' ) 
        {
            $this->intextinput = false;
        }
        elseif ($this->feed_type == RSS and $this->current_namespace == '' and $el == 'image' ) 
        {
            $this->inimage = false;
        }
        elseif ($this->feed_type == ATOM and in_array($el, $this->_CONTENT_CONSTRUCTS) )
        {    
            $this->incontent = false;
        }
        elseif ($el == 'channel' or $el == 'feed' ) 
        {
            $this->inchannel = false;
        }
        elseif ($this->feed_type == ATOM and $this->incontent  ) {
            // balance tags properly
            // note:  i don't think this is actually neccessary
            if ( $this->stack[0] == $el ) 
            {
                $this->append_content("</$el>");
            }
            else {
                $this->append_content("<$el />");
            }

            array_shift( $this->stack );
        }
        else {
            array_shift( $this->stack );
        }
        
        $this->current_namespace = false;
    }
    
    function concat (&$str1, $str2="") {
        if (!isset($str1) ) {
            $str1="";
        }
        $str1 .= $str2;
    }
    
    function append_content($text) {
        if ( $this->initem ) {
            $this->concat( $this->current_item[ $this->incontent ], $text );
        }
        elseif ( $this->inchannel ) {
            $this->concat( $this->channel[ $this->incontent ], $text );
        }
    }
    
    // smart append - field and namespace aware
    function append($el, $text) {
        if (!$el) {
            return;
        }
        if ( $this->current_namespace ) 
        {
            if ( $this->initem ) {
                $this->concat(
                    $this->current_item[ $this->current_namespace ][ $el ], $text);
            }
            elseif ($this->inchannel) {
                $this->concat(
                    $this->channel[ $this->current_namespace][ $el ], $text );
            }
            elseif ($this->intextinput) {
                $this->concat(
                    $this->textinput[ $this->current_namespace][ $el ], $text );
            }
            elseif ($this->inimage) {
                $this->concat(
                    $this->image[ $this->current_namespace ][ $el ], $text );
            }
        }
        else {
            if ( $this->initem ) {
                $this->concat(
                    $this->current_item[ $el ], $text);
            }
            elseif ($this->intextinput) {
                $this->concat(
                    $this->textinput[ $el ], $text );
            }
            elseif ($this->inimage) {
                $this->concat(
                    $this->image[ $el ], $text );
            }
            elseif ($this->inchannel) {
                $this->concat(
                    $this->channel[ $el ], $text );
            }
            
        }
    }
    
    function normalize () {
        // if atom populate rss fields
        if ( $this->is_atom() ) {
            $this->channel['descripton'] = $this->channel['tagline'];
            for ( $i = 0; $i < count($this->items); $i++) {
                $item = $this->items[$i];
                if ( isset($item['summary']) )
                    $item['description'] = $item['summary'];
                if ( isset($item['atom_content']))
                    $item['content']['encoded'] = $item['atom_content'];
                
                $this->items[$i] = $item;
            }        
        }
        elseif ( $this->is_rss() ) {
            $this->channel['tagline'] = $this->channel['description'];
            for ( $i = 0; $i < count($this->items); $i++) {
                $item = $this->items[$i];
                if ( isset($item['description']))
                    $item['summary'] = $item['description'];
                if ( isset($item['content']['encoded'] ) )
                    $item['atom_content'] = $item['content']['encoded'];
            
                $this->items[$i] = $item;
            }
        }
    }
    
    function is_rss () {
        if ( $this->feed_type == RSS ) {
            return $this->feed_version;    
        }
        else {
            return false;
        }
    }
    
    function is_atom() {
        if ( $this->feed_type == ATOM ) {
            return $this->feed_version;
        }
        else {
            return false;
        }
    }

    function map_attrs($k, $v) {
        return "$k=\"$v\"";
    }

    function error( $errormsg, $lvl = E_USER_WARNING ) {
        // append PHP's error message if track_errors enabled
        if ( isset($php_errormsg) ) {
            $errormsg .= " ($php_errormsg)";
        }
        if ( MAGPIE_DEBUG ) {
            trigger_error( $errormsg, $lvl);
        } else {
            error_log( $errormsg, 0);
        }
    }

}
require_once( dirname(__FILE__) . '/class-snoopy.php');

function fetch_rss ($url) {
    // initialize constants
    init();
    
    if ( !isset($url) ) {
        // error("fetch_rss called without a url");
        return false;
    }
    
    // if cache is disabled
    if ( !MAGPIE_CACHE_ON ) {
        // fetch file, and parse it
        $resp = _fetch_remote_file( $url );
        if ( is_success( $resp->status ) ) {
            return _response_to_rss( $resp );
        }
        else {
            // error("Failed to fetch $url and cache is off");
            return false;
        }
    } 
    // else cache is ON
    else {
        // Flow
        // 1. check cache
        // 2. if there is a hit, make sure its fresh
        // 3. if cached obj fails freshness check, fetch remote
        // 4. if remote fails, return stale object, or error
        
        $cache = new RSSCache( MAGPIE_CACHE_DIR, MAGPIE_CACHE_AGE );
        
        if (MAGPIE_DEBUG and $cache->ERROR) {
            debug($cache->ERROR, E_USER_WARNING);
        }
        
        
        $cache_status      = 0;        // response of check_cache
        $request_headers = array(); // HTTP headers to send with fetch
        $rss              = 0;        // parsed RSS object
        $errormsg         = 0;        // errors, if any
        
        if (!$cache->ERROR) {
            // return cache HIT, MISS, or STALE
            $cache_status = $cache->check_cache( $url );
        }

        // if object cached, and cache is fresh, return cached obj
        if ( $cache_status == 'HIT' ) {
            $rss = $cache->get( $url );
            if ( isset($rss) and $rss ) {
                $rss->from_cache = 1;
                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;
        
    }