PHP 开发 APP 接口 学习笔记与总结

1.PHP 生成 XML 数据

① 拼接字符串

② 使用系统类（DomDocument，XMLWriter，SimpleXML）

例1 使用 PHP 系统类中的 DomDocument 类：

<?php
$dom = new DomDocument('1.0','utf-8');
$element = $dom->createElement('test','This is a root element');
$dom->appendChild($element);
echo $dom->saveXML();

页面输出

This is a root element

查看源代码显示：

<?xml version="1.0" encoding="utf-8"?>
<test>This is a root element</test>

例2 拼接字符串

//修改 http 头信息
header("Content-Type:text/xml");
//xml头信息
$xml = "<?xml version='1.0' encoding='utf-8'?>
";
//根节点开始标签
$xml .= "<root>
";
//code
$xml .= "<code>200</code>
";    
//message
$xml .= "<message>数据返回成功</message>
";    
//data
$xml .= "<data>
";    
$xml .= "<id>1</id>
";
$xml .= "<name>John</name>
";
$xml .= "</data>
";
//根节点结束标签
$xml .= "</root>";

echo $xml;
exit();

页面输出：

This XML file does not appear to have any style information associated with it. The document tree is shown below.
<root>
<code>200</code>
<message>数据返回成功</message>
<data>
<id>1</id>
<name>John</name>
</data>
</root>

http 响应头信息：

2.XML 方式封装通信接口

<?php

class Response{
    /**
    * 按 xml 方式输出通信数据
    * @param integer $code 状态码
    * @param string $message 提示信息
    * @param array $data 数据
    * return string
    */
    public static function xml($code,$message,$data){

        if(!is_numeric($code)){
            return '';
        }

        $result = array(
            'code' => $code,
            'message' => $message,
            'data' => $data
        );

        //修改 http 头信息
        header("Content-Type:text/xml");
        //xml头信息
        $xml = "<?xml version='1.0' encoding='utf-8'?>";
        //根节点开始标签
        $xml .= "<root>";

        $xml .= self::xmlToEncode($result);

        //根节点结束标签
        $xml .= "</root>";

        echo $xml;
        exit();
    }

    //解析$result至xml
    public static function xmlToEncode($data){
        $xml = $attr = "";
        foreach($data as $k=>$v){
            //如果$k是数字(data(code,message,data中的data)数据里面还含有索引数组),要进行如下判断
            if(is_numeric($k)){
                $attr = "id='{$k}'";
                $k = 'item ';
            }

            $xml .= "<{$k} {$attr}>";
            //如果$v是数组，则递归调用该方法
            if(is_array($v)){
                $xml .= self::xmlToEncode($v);
            }else{
                $xml .= $v;
            }
            $xml .= "</{$k}>";
        }

        return $xml;
    }
}

调用该页面 test.php

$data 第一种情况：

<?php
require 'response.php';

$data = array(
    'id'=>1,
    'name'=>'Mary'
);
Response::xml(200,'数据返回成功',$data);

页面输出：

This XML file does not appear to have any style information associated with it. The document tree is shown below.
<root>
<code>200</code>
<message>数据返回成功</message>
<data>
<id>1</id>
<name>Mary</name>
</data>
</root>

$data 第二种情况

<?php
require 'response.php';

$data = array(
    'id'=>1,
    'name'=>'Mary',
    'type'=>array(1,3,6) //<0>1</0><1>3</1><2>6</2>  => <item id="0">1</item>...
);

Response::xml(200,'数据返回成功',$data);

页面输出：

This XML file does not appear to have any style information associated with it. The document tree is shown below.
<root>
<code>200</code>
<message>数据返回成功</message>
<data>
<id>1</id>
<name>Mary</name>
<type>
<item id="0">1</item>
<item id="1">3</item>
<item id="2">6</item>
</type>
</data>
</root>

$data 第三中情况：

<?php
require 'response.php';

$data = array(
    'id'=>1,
    'name'=>'Mary',
    'type'=>array('a'=>1,'b'=>3,'c'=>6)
);
Response::xml(200,'数据返回成功',$data);

页面输出：

This XML file does not appear to have any style information associated with it. The document tree is shown below.
<root>
<code>200</code>
<message>数据返回成功</message>
<data>
<id>1</id>
<name>Mary</name>
<type>
<a>1</a>
<b>3</b>
<c>6</c>
</type>
</data>
</root>