The Library, Reloaded

// Class to parse and query a Delicious Library database
// Sample usage:
// $oLibrary = new CLibrary('Library Media Data.xml');
// print_r( $oLibrary->query( array("tagname" => "/book/",
//                            "author" => "/douglas/i") ) );

class CLibrary { // {{{
  var $m_oDom;

  // Constructor - simply parses the XML into memory
  function CLibrary($szFilename = "") { // {{{
    if($szFilename && file_exists($szFilename)) {
      if ( !$this->m_oDom = domxml_open_file($szFilename) ) {
        echo "Error while parsing the document $szFilename\n";
        exit;
      }
    }
  } // Library }}}

  // For each XML item tossed in, see if it's a valid element and
  // if it matches all of the regexps in the filter
  function filter( $oItem, $aFilter ) { // {{{
    if($aFilter == "")
      return true; // no filter matches everything
    if($oItem->type != XML_ELEMENT_NODE)
      return false; // not interested in this kind of items
    $nMatches = 0;
    if($aFilter["tagname"]) { // special case
      if(preg_match( $aFilter["tagname"], $oItem->tagname ) )
        $nMatches++;
    }
    foreach($aFilter as $szAttribute => $szRegexp) {
      if(preg_match($szRegexp, $oItem->get_attribute($szAttribute))) {
        $nMatches++;
      }
    }
    if($nMatches == count($aFilter))
      return true;
    return false;
  } // filter }}}


  // Build a nice alphabetical index of items by a given field
  function index( $szField, $aFilter = "" ) { // {{{
    $aIndex = array();
    $oRoot = $this->m_oDom->document_element();
    $aNodes = $oRoot->child_nodes();
    print_r( $oRoot );
    foreach( $aNodes as $oNode ) {
      if(@$oNode->tagname == "items" ) {
        $aItems = $oNode->child_nodes();
        foreach( $aItems as $oItem ) {
          if($this->filter($oItem, $aFilter)) {
            // Get rid of extra whitespace
            $szBuffer = trim($oItem->get_attribute($szField));
            $szBuffer = preg_replace("/\s+/m", " ", $szBuffer);
            $aLetter = strtoupper(substr($szBuffer,0,1));
            if(@$aIndex[$aLetter][$szBuffer])
              $aIndex[$aLetter][$szBuffer][] = $oItem->get_attribute("uuid");
            else
              $aIndex[$aLetter][$szBuffer] = array($oItem->get_attribute("uuid"));
          }
        }
      }
    }
    ksort($aIndex);
    return $aIndex;
  } // index }}}

  // Query the database
  function query( $aFilter = "" ) { // {{{
    $aResult = array();
    $oRoot = $this->m_oDom->document_element();
    $aNodes = $oRoot->child_nodes();
    foreach( $aNodes as $oNode ) {
      if(@$oNode->tagname == "items" ) {
        $aItems = $oNode->child_nodes();
        foreach( $aItems as $oItem ) {
          if($this->filter($oItem, $aFilter)) {
            $szUUID = $oItem->get_attribute("uuid");
            $aResult[$szUUID]["author"] = $oItem->get_attribute("author");
            $aResult[$szUUID]["title"] = $oItem->get_attribute("title");
            $aResult[$szUUID]["publisher"] = $oItem->get_attribute("publisher");
          }
        }
      }
    }
    return $aResult;
  } // index }}}
} // CLibrary }}}