PHP返回XML与JSON数据

//return xml format data
public function read_get_xml(){
//
	header("Content-type:text/xml");
	$article="<xml version='1.0' encoding='UTF-8'?>
";
	$article.="<article>
";
	$article.="<id>1</id>"
;
	$article.="<content>mycontent</content>
";
	$article.="<author>valentine</author>
";
	$article.="<time>2014.06.05</time>
";
	$article.="<source>cnblogs</source>
";
	$article.="<article>xml_encode</article>
";
	$article.="<pageurl>http://cnblogs.com</pageurl>
";
	$article.="</article>
";
	//
	echo $article;
	exit;
}

//return json format data
public function read_get_json(){
	//use table tb_smartphone
	$article=M('tb_smartphone');
	//sql
	$articleRes=$article->limit(10)
	->getField('id,content,author,time,source,title,pageurl');
	//data
	$this->response($articleRes,'json');
	return json_encode($articleRes);
}