array2xml和xml2array，xml与array的互相转化

php在做后台服务器的时候，经常会遇到这种情况，需要解析来自前台的xml文件，并将数据以xml格式返回，在这种情况下，xml与php中关联数组的转化是非常频繁的事情。比如flex和其他客户端程序与服务器的交互，经常会使用这种方法。下面是我归纳的两个方法，大大简化了xml与数组相互转化的工作量。

/**
     *
     * 将简单数组转化为简单的xml
     * @param string $data  要进行转化的数组
     * @param string $tag   要使用的标签
     * @example
     * $arr = array(
        'rtxAccount'=>'aaron','ipAddr'=>'192.168.0.12',
        'conferenceList'=>array('conference'=>
                            array(
                                array('conferenceId'=>1212,'conferenceTitle'=>'quanshi 444','smeAccount'=>'[e-mail]'),
                                array('conferenceId'=>454,'conferenceTitle'=>'quanshi meetting','smeAccount'=>'[e-mail]'),
                                array('conferenceId'=>6767,'conferenceTitle'=>'quanshi meetting','smeAccount'=>'[e-mail]'),
                                array('conferenceId'=>232323,'conferenceTitle'=>'quanshi uuu','smeAccount'=>'[e-mail]'),
                                array('conferenceId'=>8989,'conferenceTitle'=>'quanshi meetting','smeAccount'=>'[e-mail]'),
                                array('conferenceId'=>1234343212,'conferenceTitle'=>'quanshi meetting','smeAccount'=>'[e-mail]')
                                )
                            )
        
                                
        );
        转化为：
        <rtxAccount>aaron</rtxAccount>
        <ipAddr>192.168.0.12</ipAddr>
        <conferenceList>
            <conference>
                <conferenceId>1212</conferenceId>
                <conferenceTitle>quanshi 444</conferenceTitle>
                <smeAccount>[e-mail]</smeAccount>
            </conference>
            <conference>
                <conferenceId>454</conferenceId>
                <conferenceTitle>quanshi meetting</conferenceTitle>
                <smeAccount>[e-mail]</smeAccount>
            </conference>
            <conference>
                <conferenceId>6767</conferenceId>
                <conferenceTitle>quanshi meetting</conferenceTitle>
                <smeAccount>[e-mail]</smeAccount>
            </conference>
            <conference>
                <conferenceId>232323</conferenceId>
                <conferenceTitle>quanshi uuu</conferenceTitle>
                <smeAccount>[e-mail]</smeAccount>
            </conference>
            <conference>
                <conferenceId>8989</conferenceId>
                <conferenceTitle>quanshi meetting</conferenceTitle>
                <smeAccount>[e-mail]</smeAccount>
            </conference>
            <conference>
                <conferenceId>1234343212</conferenceId>
                <conferenceTitle>quanshi meetting</conferenceTitle>
                <smeAccount>[e-mail]</smeAccount>
            </conference>
        </conferenceList>
     */
    function array2xml($data,$tag = '')
    {
        $xml = '';
        
        foreach($data as $key => $value)
        {
            if(is_numeric($key))
            {
                if(is_array($value))
                {
                    $xml .= "<$tag>";
                    $xml .= array2xml($value);
                    $xml .="</$tag>";
                }
                else
                {
                    $xml .= "<$tag>$value</$tag>";
                }    
            }
            else
            {
                if(is_array($value))
                {
                    $keys = array_keys($value);
                    if(is_numeric($keys[0]))
                    {
                        $xml .=array2xml($value,$key);
                    }
                    else
                    {
                        $xml .= "<$key>";
                        $xml .=array2xml($value);
                        $xml .= "</$key>";
                    }
                    
                }
                else
                {
                    $xml .= "<$key>$value</$key>";
                }
            }
        }
        return $xml;
    }             
}

xml2array

/**
	 * 
	 * 将简单的xml转化成关联数组
	 * @param string $xmlString  xml字符串
	 * @example
	 * <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<RTXConferenceReqDTO>
	<conferenceTitle>IT交流会</conferenceTitle>
	<startTime>2011-12-19 12:00:00</startTime>
	<rtxAccount>andy1111111</rtxAccount>
	<ipAddr>192.168.1.56</ipAddr>
	<duration>120</duration>
	<conferenceType>1</conferenceType>
	<invitees>
		<invitee>
			<rtxAccount>被邀请人1的RTX账号</rtxAccount>
			<tel>被邀请人1电话号码</tel>
		</invitee>
		<invitee>
			<rtxAccount>被邀请人2的RTX账号</rtxAccount>
			<tel>被邀请人2电话号码</tel>
		</invitee>
	</invitees>
</RTXConferenceReqDTO>
转化之后的关联数组：
Array
(
    [conferenceTitle] => IT交流会
    [startTime] => 2011-12-19 12:00:00
    [rtxAccount] => andy1111111
    [ipAddr] => 192.168.1.56
    [duration] => 120
    [conferenceType] => 1
    [invitees] => Array
        (
            [invitee] => Array
                (
                    [0] => Array
                        (
                            [rtxAccount] => 被邀请人1的RTX账号
                            [tel] => 被邀请人1电话号码
                        )

                    [1] => Array
                        (
                            [rtxAccount] => 被邀请人2的RTX账号
                            [tel] => 被邀请人2电话号码
                        )

                )

        )

)
	 */
	function xml2array($xmlString = '')
	{
		$targetArray = array();
		$xmlObject = simplexml_load_string($xmlString);
		$mixArray = (array)$xmlObject;
		foreach($mixArray as $key => $value)
		{
			if(is_string($value))
			{
				$targetArray[$key] = $value;
			}
			if(is_object($value))
			{
				$targetArray[$key] = xml2array($value->asXML());
			}
			if(is_array($value))
			{
				foreach($value as $zkey => $zvalue)
				{
					if(is_numeric($zkey))
					{
						$targetArray[$key][] = xml2array($zvalue->asXML());
					}
					if(is_string($zkey))
					{
						$targetArray[$key][$zkey] = xml2array($zvalue->asXML());
					}
				}
			}
		}
		return $targetArray;
		
	}