Detailed explanation of PHP return data formatting class

<?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 &#39;<pre class="brush:php;toolbar:false">&#39;;

        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

?>