RSS olvasó és megjelenítő PHP script

A program alapja a myRSSParser class, amely kimondottan RSS 2.0 forrásokra lett megírva. Ebből adódóan hiába próbálunk beleadni más forrásokat valószínűleg hibákat fogunk kapni. A program alapvetően rémesen egyszerű. Először is szükségünk van egy Parser-re, amely a kapott RSS forrást darabokra szedi. Ennek a kódja így fest:

 class myRSSParser
  {
    # keeps track of current and preceding elements
    var $tags = array();

    # array containing all feed data
    var $output = array();

    # return value for display functions
    var $retval = "";

    # constructor for new object
    function myRSSParser($file)
    {
      # instantiate xml-parser and assign event handlers
      $xml_parser = xml_parser_create("");
      xml_set_object($xml_parser, $this);
      xml_set_element_handler($xml_parser, "startElement", "endElement");
      xml_set_character_data_handler($xml_parser, "parseData");

      # open file for reading and send data to xml-parser
      $fp = @fopen($file, "r") or die("myRSSParser: Could not open $file for input");
      while($data = fread($fp, 4096)) {
        xml_parse($xml_parser, $data, feof($fp)) or die(
          sprintf("myRSSParser: Error %s at line %d
",
          xml_error_string(xml_get_error_code($xml_parser)),
          xml_get_current_line_number($xml_parser))
        );
      }
      fclose($fp);

      # dismiss xml parser
      xml_parser_free($xml_parser);
    }

    function startElement($parser, $tagname, $attrs=array())
    {
      # RSS 2.0 - ENCLOSURE
      if($tagname == "ENCLOSURE" && $attrs) {
        $this->startElement($parser, "ENCLOSURE");
        foreach($attrs as $attr => $attrval) {
          $this->startElement($parser, $attr);
          $this->parseData($parser, $attrval);
          $this->endElement($parser, $attr);
        }
        $this->endElement($parser, "ENCLOSURE");
      }

      # check if this element can contain others - list may be edited
      if(preg_match("/^(RDF|RSS|CHANNEL|IMAGE|ITEM)/", $tagname)) {
        if($this->tags) {
          $depth = count($this->tags);
          list($parent, $num) = each($tmp = end($this->tags));
          if($parent) $this->tags[$depth-1][$parent][$tagname]++;
        }
        array_push($this->tags, array($tagname => array()));
      } else {
        if(!preg_match("/^(A|B|I)$/", $tagname)) {
          # add tag to tags array
          array_push($this->tags, $tagname);
        }
      }
    }

    function endElement($parser, $tagname)
    {
      if(!preg_match("/^(A|B|I)$/", $tagname)) {
        # remove tag from tags array
        array_pop($this->tags);
      }
    }

    function parseData($parser, $data)
    {
      # return if data contains no text
      if(!trim($data)) return;
      $evalcode = "\$this->output";
      foreach($this->tags as $tag) {
        if(is_array($tag)) {
          list($tagname, $indexes) = each($tag);
          $evalcode .= "[\"$tagname\"]";
          if(${$tagname}) $evalcode .= "[" . (${$tagname} - 1) . "]";
          if($indexes) extract($indexes);
        } else {
          if(preg_match("/^([A-Z]+):([A-Z]+)$/", $tag, $matches)) {
            $evalcode .= "[\"$matches[1]\"][\"$matches[2]\"]";
          } else {
            $evalcode .= "[\"$tag\"]";
          }
        }
      }
      eval("$evalcode = $evalcode . '" . addslashes($data) . "';");
    }

    # display a single channel as HTML
    function display_channel($data, $limit)
    {
      extract($data);
      if($IMAGE) {
        # display channel image(s)
        foreach($IMAGE as $image) $this->display_image($image);
      }
      if($TITLE) {
        # display channel information
        $this->retval .= "";
        if($LINK) $this->retval .= "";
        $this->retval .= stripslashes($TITLE);
        if($LINK) $this->retval .= "";
        $this->retval .= "\n";
        if($DESCRIPTION) $this->retval .= "$DESCRIPTION\n\n";
        $tmp = array();
        if($PUBDATE) $tmp[] = "Published: $PUBDATE";
        if($COPYRIGHT) $tmp[] = "Copyright: $COPYRIGHT";
        if($tmp) $this->retval .= "" . implode("
\n", $tmp) . "\n\n";
        $this->retval .= "\n\n";
      }
      if($ITEM) {
        # display channel item(s)
        foreach($ITEM as $item) {
          $this->display_item($item, "CHANNEL");
          if(is_int($limit) && --$limit <= 0) break; } } } # display a single image as HTML function display_image($data, $parent="") { extract($data); if(!$URL) return; $this->retval .= "";
      if($LINK) $this->retval .= "";
      $this->retval .= "retval .= " width=\"$WIDTH\" height=\"$HEIGHT\"";
      $this->retval .= " border=\"0\" alt=\"$TITLE\">";
      if($LINK) $this->retval .= "";
      $this->retval .= "\n\n";
    }

    # display a single item as HTML
    function display_item($data, $parent)
    {
      extract($data);
      if(!$TITLE) return;

      $this->retval .=  "";
      if($LINK) $this->retval .=  "";
      $this->retval .= stripslashes($TITLE);
      if($LINK) $this->retval .= "";
      $this->retval .=  "";
      if(!$PUBDATE && $DC["DATE"]) $PUBDATE = $DC["DATE"];
      if($PUBDATE) $this->retval .= " ($PUBDATE)";
      $this->retval .=  "\n";

      # use feed-formatted HTML if provided
      if($CONTENT["ENCODED"]) {
        $this->retval .= "" . stripslashes($CONTENT["ENCODED"]) . "\n";
      } elseif($DESCRIPTION) {
        $this->retval .=  "" . stripslashes($DESCRIPTION) . "\n\n";
      }

      # RSS 2.0 - ENCLOSURE
      if($ENCLOSURE) {
        $this->retval .= "Media: ";
        $this->retval .= $ENCLOSURE['TYPE'];
        $this->retval .= " ({$ENCLOSURE['LENGTH']} bytes)\n\n";
      }

      if($COMMENTS) {
        $this->retval .= "";
        $this->retval .= "Comments";
        $this->retval .= "\n\n";
      }
    }

    function fixEncoding($input, $output_encoding)
    {
      if(!function_exists('mb_detect_encoding')) return $input;

      $encoding = mb_detect_encoding($input);
      switch($encoding) {
        case 'ASCII':
        case $output_encoding:
          return $input;
        case '':
          return mb_convert_encoding($input, $output_encoding);
        default:
          return mb_convert_encoding($input, $output_encoding, $encoding);
      }
    }

    # display entire feed as HTML
    function getOutput($limit=false, $output_encoding='UTF-8')
    {
      $this->retval = "";
      $start_tag = key($this->output);

      switch($start_tag) {
        case "RSS":
          # new format - channel contains all
          foreach($this->output[$start_tag]["CHANNEL"] as $channel) {
            $this->display_channel($channel, $limit);
          }
          break;

        case "RDF:RDF":
          # old format - channel and items are separate
          if(isset($this->output[$start_tag]['IMAGE'])) {
            foreach($this->output[$start_tag]['IMAGE'] as $image) {
              $this->display_image($image);
            }
          }
          foreach($this->output[$start_tag]['CHANNEL'] as $channel) {
            $this->display_channel($channel, $limit);
          }
          foreach($this->output[$start_tag]['ITEM'] as $item) {
            $this->display_item($item, $start_tag);
          }
          break;

        case "HTML":
          die("Error: cannot parse HTML document as RSS");

        default:
          die("Error: unrecognized start tag '$start_tag' in getOutput()");
      }

      return $this->fixEncoding($this->retval, $output_encoding);
    }

    # return raw data as array
    function getRawOutput($output_encoding='UTF-8')
    {
      return $this->fixEncoding($this->output, $output_encoding);
    }
  }

innét le is lehet tölteni (rss.parser.php)

Miután ezt felmásoltuk a szerverre jön maga a fájl, amely kiiratja az RSS hírforrást. Ebben a fájlban végezhetünk el különböző beállításokat értelemszerűen értelmezve a következő változókat:
$FEEDURL - Ez az RSS címe pl.: http://www.sg.hu/plain/rss.xml
$NUMITEMS - mennyi bejegyzést akarunk kilistázni
$TIMEFORMAT - a dátum milyen formában jelenjen meg.
$CACHEFILE - a letárolt tartalmat hova mentse a program (erre azért van szükség, hogy ne minden oldatelöltéskor szedjük le az RSS-t, mert az belassítaná a rendszert, hanem megadott időközönként frissítsünk csak)
$CACHETIME - milyen időközönként kapcsolódjon fel az RSS-re és szedje le az új bejegyzéseket.

Ennyit kell gyakorlatilag tudni a beállításokhoz most pedig lássuk a magát a kódot:

header('Content-Type: text/html; charset=utf-8'); 
  # define script parameters
  $FEEDURL    = "http://www.sg.hu/plain/rss.xml";
  
  $NUMITEMS   = 20;
  $TIMEFORMAT = "Y. F j., h:i";
  $CACHEFILE  = "/tmp/" . md5($FEEDURL);
  $CACHETIME  = 1; # hours

  # download the feed iff a cached version is missing or too old
  if(!file_exists($CACHEFILE) || ((time() - filemtime($CACHEFILE)) > 3600 * $CACHETIME)) {
    if($feed_contents = @file_get_contents($FEEDURL)) {
      # write feed contents to cache file
      $fp = fopen($CACHEFILE, 'w');
      fwrite($fp, $feed_contents);
      fclose($fp);
    }
  }                                                        
  include "rss.parser.php";
  $rss_parser = new myRSSParser($CACHEFILE);

  # read feed data from cache file
  $feeddata = $rss_parser->getRawOutput();
  extract($feeddata['RSS']['CHANNEL'][0], EXTR_PREFIX_ALL, 'rss');

  # display leading image
  if(isset($rss_IMAGE[0]) && $rss_IMAGE[0]) {
    extract($rss_IMAGE[0], EXTR_PREFIX_ALL, 'img');
    echo "";
  }

  # display feed title
  echo "".htmlspecialchars($rss_TITLE)."";

  # display feed items
  $count = 0;
  foreach($rss_ITEM as $itemdata) {
    # article title
    echo "".htmlspecialchars(stripslashes($itemdata['TITLE']))."
";
    # article description 
    echo htmlspecialchars(stripslashes($itemdata['DESCRIPTION'])),"
\n";
    # article date 
    echo "",date($TIMEFORMAT, strtotime($itemdata['PUBDATE'])),"\n\n";
    if(++$count >= $NUMITEMS) break;
  }

innét le tölthető (rss.php)

A php 27. sorától kezdve lehet szépítgetni a megjelenítést. A program, ha képet tlaál az RSS-ben az automatikusan kirakja, ezen felül kiírja az RSS címét a bejegyzések címeit leírásait és dátumát is.

RSS olvasó és megjelenítő PHP script

"; if($LINK) $this->retval .= ""; $this->retval .= stripslashes($TITLE); if($LINK) $this->retval .= ""; $this->retval .= "

".htmlspecialchars($rss_TITLE)."

#totalstudio