<?php

/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4 foldmethod=marker: */

// LICENSE AGREEMENT. If folded, press za here to unfold and read license {{{ 

/**
* +-----------------------------------------------------------------------------+
* | Copyright (c) 2004-2006 Sergio Goncalves Carvalho                                |
* +-----------------------------------------------------------------------------+
* | This file is part of XML_RPC2.                                              |
* |                                                                             |
* | XML_RPC2 is free software; you can redistribute it and/or modify            |
* | it under the terms of the GNU Lesser General Public License as published by |
* | the Free Software Foundation; either version 2.1 of the License, or         |
* | (at your option) any later version.                                         |
* |                                                                             |
* | XML_RPC2 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 Lesser General Public License for more details.                         |
* |                                                                             |
* | You should have received a copy of the GNU Lesser General Public License    |
* | along with XML_RPC2; if not, write to the Free Software                     |
* | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA                    |
* | 02111-1307 USA                                                              |
* +-----------------------------------------------------------------------------+
* | Author: Sergio Carvalho <sergio.carvalho@portugalmail.com>                  |
* +-----------------------------------------------------------------------------+
*
* @category   XML
* @package    XML_RPC2
* @author     Sergio Carvalho <sergio.carvalho@portugalmail.com>  
* @copyright  2004-2006 Sergio Carvalho
* @license    http://www.gnu.org/copyleft/lesser.html  LGPL License 2.1
* @version    CVS: $Id$
* @link       http://pear.php.net/package/XML_RPC2
*/

// }}}

// dependencies {{{
require_once 'XML/RPC2/Exception.php';
require_once 'XML/RPC2/Backend/Php/Value.php';
require_once 'XML/RPC2/Backend/Php/Value/Struct.php';
// }}}

/**
 * XML-RPC response backend class. 
 *
 * This class represents an XML_RPC request, exposing the methods 
 * needed to encode/decode an xml-rpc response.
 *
 * @category   XML
 * @package    XML_RPC2
 * @author     Sergio Carvalho <sergio.carvalho@portugalmail.com>  
 * @copyright  2004-2006 Sergio Carvalho
 * @license    http://www.gnu.org/copyleft/lesser.html  LGPL License 2.1
 * @link       http://pear.php.net/package/XML_RPC2 
 */
class XML_RPC2_Backend_Php_Response
{
    
    // {{{ encode()
    
    /**
     * Encode a normal XML-RPC response, containing the provided value
     *
     * You may supply a php-native value, or an XML_RPC2_Backend_Php_Value instance, to be returned. Usually providing a native value
     * is more convenient. However, for some types, XML_RPC2_Backend_Php_Value::createFromNative can't properly choose the xml-rpc 
     * type. In these cases, constructing an XML_RPC2_Backend_Php_Value and using it as param here is the only way to return the desired 
     * type.
     *
     * @see http://www.xmlrpc.com/spec
     * @see XML_RPC2_Backend_Php_Value::createFromNative
     * @param mixed $param The result value which the response will envelop
     * @param string $encoding encoding
     * @return string The XML payload
     */
    public static function encode($param, $encoding = 'utf-8') 
    {
        if (!$param instanceof XML_RPC2_Backend_Php_Value) {
            $param = XML_RPC2_Backend_Php_Value::createFromNative($param);
        }
        $result  = '<?xml version="1.0" encoding="' .  $encoding . '"?>' . "\n";
        $result .= '<methodResponse><params><param><value>' . $param->encode() . '</value></param></params></methodResponse>';
        return $result;
    }
    
    // }}}
    // {{{ encodeFault()
    
    /**
     * Encode a fault XML-RPC response, containing the provided code and message
     *
     * @see http://www.xmlrpc.com/spec
     * @param int $code Response code
     * @param string $message Response message
     * @param string $encoding encoding
     * @return string The XML payload
     */
    public static function encodeFault($code, $message, $encoding = 'utf-8')
    {
        $value = new XML_RPC2_Backend_Php_Value_Struct(array('faultCode' => (int) $code, 'faultString' => (string) $message));
        $result  = '<?xml version="1.0" encoding="' .  $encoding . '"?>' . "\n";
        $result .= '<methodResponse><fault><value>' . $value->encode() . '</value></fault></methodResponse>';
        return $result;
    }
    
    // }}}
    // {{{ decode()
    
    /**
     * Parse a response and either return the native PHP result.
     *
     * This method receives an XML-RPC response document, in SimpleXML format, decodes it and returns the payload value.
     *
     * @param SimpleXmlElement $xml The Transport XML
     * @return mixed The response payload
     *
     * @see http://www.xmlrpc.com/spec
     * @throws XML_RPC2_FaultException Signals the decoded response was an XML-RPC fault
     * @throws XML_RPC2_DecodeException Signals an ill formed payload response section
     */
    public static function decode(SimpleXMLElement $xml) 
    {
        $faultNode = $xml->xpath('/methodResponse/fault');
        if (count($faultNode) == 1) {
            throw XML_RPC2_FaultException::createFromDecode($faultNode[0]);
        }
        $paramValueNode = $xml->xpath('/methodResponse/params/param/value');
        if (count($paramValueNode) == 1) {
            return XML_RPC2_Backend_Php_Value::createFromDecode($paramValueNode[0])->getNativeValue();
        }
        throw new XML_RPC2_DecodeException('Unable to decode xml-rpc response. No fault nor params/param elements found');
    }
    
    // }}}
    
}

?>