php实现的返回数据格式化类实例

<?php 
/** 返回数据格式化类 
*  Date:  2011-08-15 
*  Author: fdipzone 
*/ 
 
class DataReturn{  // class start 
 
  private $type; 
  private $xmlroot; 
  private $callback; 
  private $returnData; 
 
  public function __construct($param=array()){ 
    $this->type = $this->exists($param,'type')? strtoupper($param['type']) : 'JSON';   // 类型 JSON,XML,CALLBACK,ARRAY 
    $this->xmlroot = $this->exists($param,'xmlroot')? $param['xmlroot'] : 'xmlroot';   // xml root dom name 
    $this->callback = $this->exists($param,'callback')? $param['callback'] : '';     // JS callback function name 
 
    $format = array(); 
    $format['retcode'] = $this->exists($param,'format.retcode')? $param['format']['retcode'] : 'retcode';//retcode 对应名称 
    $format['msg'] = $this->exists($param,'format.msg')? $param['format']['msg'] : 'msg';        //msg 对应名称 
    $format['data'] = $this->exists($param,'format.data')? $param['format']['data'] : 'data';      //data 对应名称 
 
    $result = array(); 
    $result[$format['retcode']] = $this->exists($param,'retcode')? $param['retcode'] : 0; 
    $result[$format['msg']] = $this->exists($param,'msg')? $param['msg'] : ''; 
    $result[$format['data']] = $this->exists($param,'data')? $param['data'] : ''; 
 
    $this->returnData = $result; 
  } 
 
  //输出数据 
  public function data_return(){ 
    ob_clean(); 
    switch($this->type){ 
      case 'JSON': 
        $this->json_return(); 
        break; 
      case 'XML': 
        $this->xml_return(); 
        break; 
      case 'CALLBACK': 
        $this->callback_return(); 
        break; 
      case 'ARRAY': 
        $this->array_return(); 
        break; 
      default: 
        $this->json_return(); 
    } 
    exit(); 
  } 
 
  //输出JSON格式数据,如有callback参数则返回JSONP格式 
  private function json_return(){ 
    header('content-type:text/html;charset=utf-8'); 
    if(empty($this->callback)){ 
      echo json_encode($this->returnData); 
    }else{ 
      echo $this->callback.'('.json_encode($this->returnData).');'; 
    } 
  } 
 
  //输出XML格式数据 
  private function xml_return(){ 
    header('content-type:text/xml;charset=utf-8'); 
    echo $this->xml_encode($this->returnData,$this->xmlroot); 
  } 
 
  //输出JSON格式数据，并调用callback方法 
  private function callback_return(){ 
    header('content-type:text/html;charset=utf-8'); 
    $this->callback = empty($this->callback)? 'callback' : $this->callback; 
    echo "<script type=\"text/javascript\">\r\n"; 
    echo $this->callback."(".json_encode($this->returnData).");\r\n"; 
    echo "</script>"; 
  } 
 
  //输出数组格式数据 
  private function array_return(){ 
    header('content-type:text/html;charset=utf-8'); 
    echo '<pre>'; 
    print_r($this->returnData); 
    echo '</pre>'; 
  } 
 
  //XML编码 
  private function xml_encode($data, $root='xmlroot', $encoding='utf-8') { 
    $xml = "<?xml version=\"1.0\" encoding=\"" . $encoding . "\"?>\n"; 
    $xml.= "<" . $root . ">\n"; 
    $xml.= $this->data_to_xml($data); 
    $xml.= "</" . $root . ">"; 
    return $xml; 
  } 
 
  //数组转XML格式 
  private function data_to_xml($data) { 
    if (is_object($data)) { 
      $data = get_object_vars($data); 
    } 
    $xml = ''; 
    foreach ($data as $key => $val) { 
      is_numeric($key) && $key = "item id=\"$key\""; 
      $xml.="<$key>"; 
      $xml.= ( is_array($val) || is_object($val)) ? $this->data_to_xml($val) : $this->cdata($val); 
      list($key, ) = explode(' ', $key); 
      $xml.="</$key>\n"; 
    } 
    return $xml; 
  } 
 
  //判断数据是否存在 
  private function exists($obj,$key=''){ 
    if($key==''){ 
      return isset($obj) && !empty($obj); 
    }else{ 
      $keys = explode('.',$key); 
      for($i=0,$max=count($keys); $i<$max; $i++){ 
        if(isset($obj[$keys[$i]])){ 
          $obj = $obj[$keys[$i]]; 
        }else{ 
          return false; 
        } 
      } 
      return isset($obj) && !empty($obj); 
    } 
  } 
 
  //判断是否需要加上<![CDATA[]]>标记 
  private function cdata($val){ 
    if(!empty($val) && !preg_match('/^[A-Za-z0-9+$]/',$val)){ 
      $val = '<![CDATA['.$val.']]>'; 
    } 
    return $val; 
  } 
}  // class end 
?> 

<?php 
  require_once('DataReturn.class.php'); 
  $param = array( // DataReturn 参数 
          'type'  => 'JSON', // 输出的类型 JSON,XML,CALLBACK,ARRAY 默认为 JSON 
          'retcode' => '1000', // retcode 的值，默认为0 
          'msg'   => '',   // msg 的值，默认为空 
          'data'  => array( // 要输出的数据 
                  'id'   => '100', 
                  'name'  => 'fdipzone', 
                  'gender' => 1, 
                  'age'  => 28 
                 ), 
          'format' => array( // 输出的数据key格式,默认为 retcode,msg,data 
                  'retcode' => 'status', 
                  'msg'   => 'info', 
                  'data'  => 'result' 
                 ), 
          'xmlroot' => 'xmlroot', // 当type=XML时,XML根节点名称，默认为xmlroot 
          'callback' => 'callback' /* 回调方法名称 
                          type=JSON时，默认为空，如不为空，则输出callback({data}); 
                          type=CALLBACK时,默认为callback，自动调用页面JS回调方法 
                       */ 
  ); 
  $obj = new DataReturn($param); // 创建DataReturn类对象 
  $obj->data_return();      // 按格式输出数据 
?>