<?php
/**
 * YQL Wrapper Class 0.1
 *
 * @author		JREAM
 * @link		http://jream.com
 * @copyright		2011 Jesse Boyer (contact@jream.com)
 * @license		GNU General Public License 3 (http://www.gnu.org/licenses/)
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details:
 * http://www.gnu.org/licenses/
 
 Uses:

	try {
		$yql = new YQL();
		$yql->format('xml');
		$yql->query('select * from weather.forecast where location=90210');
		$yql->submit();
		$data = $yql->get();
	} catch (Exception $e) {
		echo $e->getMessage();
	}
 
 */
 
class YQL
{

	/** @var string $_endpoint The location to query to */
	private $_endpoint = "http://query.yahooapis.com/v1/public/yql";
	
	/** @var string $_query The YQL query to pass */
	private $_query;
	
	/** @var string $_format The format to return back */
	private $_format = 'xml';
	
	/** @var array $_flag Flag for making sure a section was called before submitting */
	private $_flag = array();
	
	/**
	* query - Prepares a query for Yahoo
	* @param string $yqlCode The YQL query to pass (See: http://developer.yahoo.com/yql/console/)
	*/
	public function query($yqlCode)
	{
		$this->_query = urlencode($yqlCode);
		array_push($this->_flag, __FUNCTION__);
	}
	
	/**
	* format - Optional. The format you'd like returned
	* @param string $format Use either 'xml' or 'json'
	*/
	public function format($format)
	{
		$this->_format = strtolower($format);
	}
	
	/**
	* submit - Sends the Query to Yahoo, we then have a stored result.
	*/
	public function submit()
	{
		/** Make sure the query method was called so we have a query */
		if (!in_array('query', $this->_flag))
		throw new Exception('You must set the query before submitting.');
				
		/** Run through cURL */
		$ch = curl_init($this->_endpoint . '?q=' . $this->_query . '&format=' . $this->_format);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		$this->_result = curl_exec($ch);

		if (curl_error($ch))
		throw new Exception(curl_error($ch));
		
		curl_close($ch);
		
		/** Let's flag submit as called */
		array_push($this->_flag, __FUNCTION__);
	}
	
	/**
	* get - Returns the result in a usable SimpleXML format (Default) or a JSON Decoded format
	*/
	public function get()
	{
		if (!in_array('submit', $this->_flag))
		throw new Exception('You must call submit before getting return data');
		
		switch ($this->_format) {
			case 'xml':
				return simplexml_load_string($this->_result);
				break;
			case 'json';
				return json_decode($this->_result);
				break;
		}
	}	

}