<?php

class SurveyAnswerRDFReader extends SurveyRDFReader
{	
    public function __construct($surveyUID)
    {
        parent::__construct($surveyUID);
	}
	
	public function loadSurvey()
	{
		parent::loadSurvey();
		$answerPath = 'surveys/answers_'.$this->surveyUID;
		$answers = array();
		
		if($handle = opendir('$answerPath'))
		{
			while (false !== ($file = readdir($handle))) {
				if(strstr($file, 'answer_'))
					$answers[] = substr($file,0,strlen($file)-4);
			}
		}
		
		foreach($answers as $answer)
		{
			$this->model->load($answerPath.'/'.$answer);
		}
	}
	
	public function getAnswer($questionID)
	{
	$querystring = '
			PREFIX 	predicates: <' . SURVEYTOOL_PREDICATES_NAMESPACE . '>
			PREFIX	resources: <' . SURVEYTOOL_RESOURCES_NAMESPACE . '>
			SELECT 	?answered 
			WHERE 	
			{
				_question	predicates:resource_type	resources:question ;
							predicates:uid				"'.$questionID.'"	;
							predicates:answered 		?answered 	
			}';
			
		$result = $this->model->sparqlQuery($querystring);
				
		return $result;
	}
}

?>