lib/RssWriter.php

   1 <?php
   2 /*
   3  * Code for creating RSS 1.0.
   4  */
   5
   6 // Encoding for RSS output.
   7 if (!defined('RSS_ENCODING'))
   8     define('RSS_ENCODING', $GLOBALS['charset']);
   9
  10 /**
  11  * A class for writing RSS 1.0.
  12  *
  13  * @see http://purl.org/rss/1.0/spec,
  14  *      http://www.usemod.com/cgi-bin/mb.pl?ModWiki
  15  */
  16 class RssWriter extends XmlElement
  17 {
  18     function RssWriter()
  19     {
  20         $this->XmlElement('rdf:RDF',
  21             array('xmlns' => "http://purl.org/rss/1.0/",
  22                 'xmlns:rdf' => 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'));
  23
  24         $this->_modules = array(
  25             //Standards
  26             'content' => "http://purl.org/rss/1.0/modules/content/",
  27             'dc' => "http://purl.org/dc/elements/1.1/",
  28             'sy' => "http://purl.org/rss/1.0/modules/syndication/",
  29             //Proposed
  30             'wiki' => "http://purl.org/rss/1.0/modules/wiki/",
  31             'ag' => "http://purl.org/rss/1.0/modules/aggregation/",
  32             'annotate' => "http://purl.org/rss/1.0/modules/annotate/",
  33             'audio' => "http://media.tangent.org/rss/1.0/",
  34             'cp' => "http://my.theinfo.org/changed/1.0/rss/",
  35             'rss091' => "http://purl.org/rss/1.0/modules/rss091/",
  36             'slash' => "http://purl.org/rss/1.0/modules/slash/",
  37             'taxo' => "http://purl.org/rss/1.0/modules/taxonomy/",
  38             'thr' => "http://purl.org/rss/1.0/modules/threading/"
  39         );
  40
  41         $this->_uris_seen = array();
  42         $this->_items = array();
  43     }
  44
  45     function registerModule($alias, $uri)
  46     {
  47         assert(!isset($this->_modules[$alias]));
  48         $this->_modules[$alias] = $uri;
  49     }
  50
  51     // Args should include:
  52     //  'title', 'link', 'description'
  53     // and can include:
  54     //  'URI'
  55     function channel($properties, $uri = false)
  56     {
  57         $this->_channel = $this->__node('channel', $properties, $uri);
  58     }
  59
  60     // Args should include:
  61     //  'title', 'link'
  62     // and can include:
  63     //  'description', 'URI'
  64     function addItem($properties, $uri = false)
  65     {
  66         $this->_items[] = $this->__node('item', $properties, $uri);
  67     }
  68
  69     // Args should include:
  70     //  'url', 'title', 'link'
  71     // and can include:
  72     //  'URI'
  73     function image($properties, $uri = false)
  74     {
  75         $this->_image = $this->__node('image', $properties, $uri);
  76     }
  77
  78     // Args should include:
  79     //  'title', 'description', 'name', and 'link'
  80     // and can include:
  81     //  'URI'
  82     function textinput($properties, $uri = false)
  83     {
  84         $this->_textinput = $this->__node('textinput', $properties, $uri);
  85     }
  86
  87     /**
  88      * Finish construction of RSS.
  89      */
  90     function finish()
  91     {
  92         if (isset($this->_finished))
  93             return;
  94
  95         $channel = &$this->_channel;
  96         $items = &$this->_items;
  97
  98         $seq = new XmlElement('rdf:Seq');
  99         if ($items) {
 100             foreach ($items as $item)
 101                 $seq->pushContent($this->__ref('rdf:li', $item));
 102         }
 103         $channel->pushContent(new XmlElement('items', false, $seq));
 104
 105         if (isset($this->_image)) {
 106             $channel->pushContent($this->__ref('image', $this->_image));
 107             $items[] = $this->_image;
 108         }
 109         if (isset($this->_textinput)) {
 110             $channel->pushContent($this->__ref('textinput', $this->_textinput));
 111             $items[] = $this->_textinput;
 112         }
 113
 114         $this->pushContent($channel);
 115         if ($items)
 116             $this->pushContent($items);
 117
 118         $this->__spew();
 119         $this->_finished = true;
 120     }
 121
 122     /**
 123      * Write output to HTTP client.
 124      */
 125     function __spew()
 126     {
 127         header("Content-Type: application/xml; charset=" . RSS_ENCODING);
 128         echo('<' . '?xml version="1.0" encoding="' . RSS_ENCODING . '"?' . ">\n");
 129         //printf("<!-- generator=\"PhpWiki-%s\" -->\n", PHPWIKI_VERSION);
 130         $this->printXML();
 131     }
 132
 133     /**
 134      * Create a new RDF <em>typedNode</em>.
 135      */
 136     function __node($type, $properties, $uri = false)
 137     {
 138         if (!$uri)
 139             $uri = $properties['link'];
 140         $attr['rdf:about'] = $this->__uniquify_uri($uri);
 141         return new XmlElement($type, $attr,
 142             $this->__elementize($properties));
 143     }
 144
 145     /**
 146      * Check object URI for uniqueness, create a unique URI if needed.
 147      */
 148     function __uniquify_uri($uri)
 149     {
 150         if (!$uri || isset($this->_uris_seen[$uri])) {
 151             $n = count($this->_uris_seen);
 152             $uri = $this->_channel->getAttr('rdf:about') . "#uri$n";
 153             assert(!isset($this->_uris_seen[$uri]));
 154         }
 155         $this->_uris_seen[$uri] = true;
 156         return $uri;
 157     }
 158
 159     /**
 160      * Convert hash of RDF properties to <em>propertyElt</em>s.
 161      */
 162     function __elementize($elements)
 163     {
 164         $out = array();
 165         foreach ($elements as $prop => $val) {
 166             $this->__check_predicate($prop);
 167             if (is_array($val))
 168                 $out[] = new XmlElement($prop, $val);
 169             elseif (is_object($val))
 170                 $out[] = $val; else
 171                 $out[] = new XmlElement($prop, false, $val);
 172         }
 173         return $out;
 174     }
 175
 176     /**
 177      * Check property predicates for XMLNS sanity.
 178      */
 179     function __check_predicate($name)
 180     {
 181         if (preg_match('/^([^:]+):[^:]/', $name, $m)) {
 182             $ns = $m[1];
 183             if (!$this->getAttr("xmlns:$ns")) {
 184                 if (!isset($this->_modules[$ns]))
 185                     die("$name: unknown namespace ($ns)");
 186                 $this->setAttr("xmlns:$ns", $this->_modules[$ns]);
 187             }
 188         }
 189     }
 190
 191     /**
 192      * Create a <em>propertyElt</em> which references another node in the RSS.
 193      */
 194     function __ref($predicate, $reference)
 195     {
 196         $attr['rdf:resource'] = $reference->getAttr('rdf:about');
 197         return new XmlElement($predicate, $attr);
 198     }
 199 }
 200
 201 /* Taken from mediawiki.
 202  * See http://www.atomenabled.org/developers/syndication/
 203  */
 204 class AtomFeed extends RssWriter
 205 {
 206
 207     // Args should include:
 208     //  'title', 'link', 'description'
 209     // and can include:
 210     //  'URI'
 211     function feed($properties, $uri = false)
 212     {
 213         global $LANG;
 214         $attr = array('xmlns' => 'http://www.w3.org/2005/Atom',
 215             'version' => '0.3', // or 1.0
 216             'lang' => $LANG);
 217         $this->_channel = $this->__node('feed', $attr, $properties, $uri);
 218     }
 219
 220     /**
 221      * Write output to HTTP client.
 222      */
 223     function __spew()
 224     {
 225         header("Content-Type: application/atom+xml; charset=" . RSS_ENCODING);
 226         echo('<' . '?xml version="1.0" encoding="' . RSS_ENCODING . '"?' . ">\n");
 227         //printf("<!-- generator=\"PhpWiki-%s\" -->\n", PHPWIKI_VERSION);
 228         $this->printXML();
 229     }
 230
 231     /**
 232      * Create a new entry
 233      */
 234     function __node($type, $attr, $properties, $uri = false)
 235     {
 236         if (!$uri)
 237             $uri = $properties['link'];
 238         //$attr['rdf:about'] = $this->__uniquify_uri($uri);
 239         return new XmlElement($type, $attr,
 240             $this->__elementize($properties));
 241     }
 242
 243     // Args should include:
 244     //  'title', 'link', author, modified, issued, created, summary,
 245     // and can include:
 246     //  comment
 247     function addItem($properties, $attr = false, $uri = false)
 248     {
 249         $this->_items[] = $this->__node('entry', $attr, $properties, $uri);
 250     }
 251
 252     /**
 253      * Print it.
 254      */
 255     function finish()
 256     {
 257         if (isset($this->_finished))
 258             return;
 259
 260         $channel = &$this->_channel;
 261         $items = &$this->_items;
 262         if ($items)
 263             $channel->pushContent($items);
 264         $this->pushContent($channel);
 265
 266         $this->__spew();
 267         $this->_finished = true;
 268     }
 269 }
 270
 271 // Local Variables:
 272 // mode: php
 273 // tab-width: 8
 274 // c-basic-offset: 4
 275 // c-hanging-comment-ender-p: nil
 276 // indent-tabs-mode: nil
 277 // End: