如题，PHP如何自动识别第三方Restful API的内容，自动渲染成 json、xml、html、serialize、csv、php等数据？

其实这也不难，因为Rest API也是基于http协议的，只要我们按照协议走，就能做到自动化识别 API 的内容，方法如下：

1、API服务端要返回明确的 http Content-Type头信息，如

Content-Type: application/json; charset=utf-8

Content-Type: application/xml; charset=utf-8

Content-Type: text/html; charset=utf-8

2、PHP端（客户端）接收到上述头信息后，再酌情自动化处理，参考代码如下：

<?php
// 请求初始化
$url = 'http://blog.snsgou.com/user/123456';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);// 返回的 http body 内容
$response = curl_exec($ch);// 返回的 http header 的 Content-Type 的内容
$contentType = curl_getinfo($ch, 'content_type');// 关闭请求资源
curl_close($ch);// 结果自动格式输出
$autoDetectFormats = array('application/xml' => 'xml','text/xml'         => 'xml','application/json' => 'json','text/json'           => 'json','text/csv'            => 'csv','application/csv'  => 'csv','application/vnd.php.serialized' => 'serialize'
);if (strpos($contentType, ';'))
{list($contentType) = explode(';', $contentType);
}$contentType = trim($contentType);if (array_key_exists($contentType, $autoDetectFormats))
{echo '_' . $autoDetectFormats[$contentType]($response);
}//+++++++++++++++++++++++++++++++++++++++++++++++++++++++
// 常用 格式化 方法
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++/*** 格式化xml输出*/
function _xml($string)
{return $string ? (array)simplexml_load_string($string, 'SimpleXMLElement', LIBXML_NOCDATA) : array();
}/*** 格式化csv输出*/
function _csv($string)
{$data = array();$rows = explode("\n", trim($string));$headings = explode(',', array_shift($rows));foreach( $rows as $row ){// 利用 substr 去掉 开始 与 结尾 的 "$data_fields = explode('","', trim(substr($row, 1, -1)));if (count($data_fields) === count($headings)){$data[] = array_combine($headings, $data_fields);}}return $data;
}/*** 格式化json输出*/
function _json($string)
{return json_decode(trim($string), true);
}/*** 反序列化输出*/
function _serialize($string)
{return unserialize(trim($string));
}/*** 执行PHP脚本输出*/
function _php($string)
{$string = trim($string);$populated = array();eval("\$populated = \"$string\";");return $populated;
}