source: Dev/branches/rest-dojo-ui/jQueryUI/server/rdfapi/syntax/TriXSerializer.php @ 312

<?php
// ----------------------------------------------------------------------------------
// Class: TriXSerializer
// ----------------------------------------------------------------------------------

/**
* Temporary implementation of a TriX-Serializer
* 
* @version  $Id$
* @author Daniel Westphal (http://www.d-westphal.de)
*
* @package      dataset
* @access       public
**/
class TriXSerializer  
{
        
        /**
        * Reference to the graphSet
        *
        * @var          object GraphSet
        * @access       private
        */
        var $graphSet;
        

        /**
        * Constructor
        * Needs a reference to a graphSet
        *
        * @param    GraphSet
        * @access       public
        */              
        function TriXSerializer(&$graphSet)
        {
                $this->graphSet=&$graphSet;
        }

        /**
        * Serialize the dataset to a TriX string
        *
        * @return   string
        * @access       public
        */
        function & serializeToString()
        {
                return $this->_serialize();
        }
        
        /**
        * Serialize the dataset to a TriX string and save in file
        *
        * @param   string
        * @access       public
        */
        function serializeToFile($fileName)
        {
                $serializedString=&$this->_serialize();
                $handle = fopen($fileName, 'w');
                fwrite($handle, $serializedString);
                fclose($handle);
        }
        
        
        /**
        * Serialize the dataset to a TriX string
        *
        * @return   string
        * @access       private
        */
        function & _serialize()
        {
                //Trix header
                $serializedString=
                        '<?xml version="1.0" encoding="utf-8"?>'.
                        '<TriX xmlns="http://www.w3.org/2004/03/trix/trix-1/">';
                
                //serialize defaultGraph if it is not empty
                $defaultGraph=& $this->graphSet->getDefaultGraph();
                if ($defaultGraph->isEmpty()===false)
                {
                        $serializedString.='<graph>';
                        for($iterator = $this->graphSet->findInDefaultGraph(null,null,null); $iterator->valid(); $iterator->next()) 
                        {
                                $serializedString.='<triple>';
                                
                                $statement=$iterator->current();
                                
                                $serializedString.=$this->_node2string($statement->getSubject());
                                $serializedString.=$this->_node2string($statement->getPredicate());
                                $serializedString.=$this->_node2string($statement->getObject());
                                
                                $serializedString.='</triple>';
                        };
                        $serializedString.='</graph>';
                }               
                        
                //serialize namedGraphs 
                foreach ($this->graphSet->listGraphNames() as $graphName)
                {
                        $serializedString.='<graph>';
                        $serializedString.='<uri>'.$graphName.'</uri>';
                        for($iterator = $this->graphSet->findInNamedGraphs(new Resource($graphName),null,null,null); $iterator->valid(); $iterator->next()) 
                        {
                                $serializedString.='<triple>';
                                
                                $statement=$iterator->current();
                                
                                $serializedString.=$this->_node2string($statement->getSubject());
                                $serializedString.=$this->_node2string($statement->getPredicate());
                                $serializedString.=$this->_node2string($statement->getObject());
                                
                                $serializedString.='</triple>';
                        };
                        $serializedString.='</graph>';
                };              
                //TriX footer   
                $serializedString.='</TriX>';   
                return $serializedString;
        }
        
        /**
        * Serialize node to a TriX string
        *
        * @param Node
        * @return   string
        * @access       private
        */
        function _node2string($node)
        {
                switch ($node)
                {
                        case (is_a($node,'BlankNode')):
                                return ('<id>'.$node->getLabel().'</id>');
                        
                        case (is_a($node,'Resource')):
                                return ('<uri>'.$node->getLabel().'</uri>');
                        
                        case (is_a($node,'Literal')):
                        
                                if ($node->dtype!=null)
                                        return ('<typedLiteral datatype="'.htmlentities($node->dtype).'">'.$node->getLabel().'</typedLiteral>');

                                if ($node->lang!=null)
                                        return ('<plainLiteral xml:lang="'.htmlentities($node->lang).'">'.$node->getLabel().'</plainLiteral>');
                                        
                                return ('<plainLiteral>'.htmlentities($node->getLabel()).'</plainLiteral>');
                }
        }
}
?>