关于php返回数据格式化类的详解

<?php
/** 返回數據格式化類
*	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';		// 類型 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 對應名稱
		$format['msg'] = $this->exists($param,'format.msg')? $param['format']['msg'] : 'msg';                //msg 對應名稱
		$format['data'] = $this->exists($param,'format.data')? $param['format']['data'] : 'data';            //data 對應名稱
		$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 = $result;
	}
	//輸出數據
	public function data_return(){
		ob_clean();
		switch($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:
				$this->json_return();
		}
		exit();
	}
	//輸出JSON格式數據,如有callback參數則返回JSONP格式
	private function json_return(){
		header('content-type:text/html;charset=utf-8');
		if(empty($this->callback)){
			echo json_encode($this->returnData);
		}else{
			echo $this->callback.'('.json_encode($this->returnData).');';
		}
	}
	//輸出XML格式數據
	private function xml_return(){
		header('content-type:text/xml;charset=utf-8');
		echo $this->xml_encode($this->returnData,$this->xmlroot);
	}
	//輸出JSON格式數據，并調用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>";
	}
	//輸出數組格式數據
	private function array_return(){
		header('content-type:text/html;charset=utf-8');
		echo '<pre class="brush:php;toolbar:false">';
		print_r($this->returnData);
		echo '

<?
    require_once('DataReturn.class.php');
    $param = array( // DataReturn 參數
                    'type'    => 'JSON', // 輸出的類型 JSON,XML,CALLBACK,ARRAY 默認為 JSON
                    'retcode' => '1000', // retcode 的值，默認為0
                    'msg'     => '',     // msg 的值，默認為空
                    'data'    => array(  // 要輸出的數據
                                    'id'     => '100',
                                    'name'   => 'fdipzone',
                                    'gender' => 1,
                                    'age'    => 28
                                 ),
                    'format'  => array(// 輸出的數據key格式,默認為 retcode,msg,data
                                    'retcode' => 'status',
                                    'msg'     => 'info',
                                    'data'    => 'result'
                                 ),
                    'xmlroot'  => 'xmlroot',  // 當type=XML時,XML根節點名稱，默認為xmlroot
                    'callback' => 'callback'  /* 回調方法名稱
                                                   type=JSON時，默認為空，如不為空，則輸出callback({data});
                                                   type=CALLBACK時,默認為callback，自動調用頁面JS回調方法
                                              */
    );
    $obj = new DataReturn($param);  // 創建DataReturn類對象
    $obj->data_return();            // 按格式輸出數據
?>