什么是RSS源？看到这片文章的人相信都知道，自己博客首页不就是一个吗？

好吧，先来一个简单点的，直接就是死代码：具体怎样使用就看RSS使用标准吧！

<?xml version = "1.0" encoding = "utf-8"?>
<RSS  version="2.0" xmlns:wfw="http://wellformedweb.org/CommentAPI/">
	<channel>
		<title>
		  优惠信息
		</title>
		<link>
		  http://localhost/test/01.PHP
		</link>
		<description>
			这里有最新优惠信息
		</description>
	</channel>
	<item>
		<title>
		  优惠信息1
		</title>
		<description>
			这里有最新优惠信息1
		</description>
	</item>
	<item>
		<title>
		  优惠信息1
		</title>
		<description>
			这里有最新优惠信息1
		</description>
	</item>
</RSS>

这个简答实现了，来个复杂的吧，动态生成RSS

RSS模板

<?xml version="1.0" encoding="utf-8"?>
<!-- RSS输出模板 用PHP动态制造channel,和item -->
<RSS version="2.0" xmlns:wfw="http://wellformedweb.org/CommentAPI/"></RSS>

<?PHP
/***
====笔记部分====
连接数据库,动态生成RSS Feed

连数据库,取最新的10条商品,输出XML Feed
***/


class Feed {
    public $title = '';  // channel的title
    public $link = '';   // channel的link
    public $description = '';   // channel的descrition;
    public $items = array();

    public $template = './Feed.xml'; //xml模板
    protected $dom = null;
    protected $RSS = null;

    public function __construct() {
        $this->dom = new DomDocument('1.0','utf-8');
        $this->dom->load($this->template);
        $this->RSS = $this->dom->getElementsByTagName('RSS')->item(0);
    }

    
    // 调用createItem,把所有的item节点都生成,再输出
    public function display() {
        $this->createChannel();
        $this->addItem($this->items);
        header('content-type: text/xml');
        echo $this->dom->savexml();
    }

    // 封装createChannel方法,用来创建RSS的唯一且必须的channel节点
    protected function createChannel() {
        $channel = $this->dom->createElement('channel');
        $channel->appendChild($this->createEle('title',$this->title));
        $channel->appendChild($this->createEle('link',$this->link));
        $channel->appendChild($this->createEle('description',$this->description));

        $this->RSS->appendChild($channel);
    }

    // 封装addItem方法,把所有的商品增加到RSS里面去
    // $list是商品列表,是二维数据,每一行是一个商品
    protected function addItem($list) {
        foreach($list as $goods) {
            $this->RSS->appendChild($this->createItem($goods));
        }
    }

    // 封装一个方法,用来造item 比如link description等等
    protected function createItem($arr) {
        $item = $this->dom->createElement('item');
        foreach($arr as $k=>$v) {
            $item->appendChild($this->createEle($k,$v));
        }

        return $item;
    }
    
    // 封装一个方法,直接创建开如 <ele>some text</ele>这样的节点
    protected function createEle($name,$value) {
        $ele = $this->dom->createElement($name);
        $text = $this->dom->createTextNode($value);
        $ele->appendChild($text);

        return $ele;
    }
}


$conn = MysqL_connect('localhost','root','');
MysqL_query('set names utf8',$conn);
MysqL_query('use test');

$sql = 'select ver as title,content as description from smth order by id desc limit 8';

$rs = MysqL_query($sql,$conn);

$list = array();
while($row = MysqL_fetch_assoc($rs)) {
    $list[] = $row;
}


$Feed = new Feed();
$Feed->title = '布尔商城';
$Feed->link = 'http://localhost/bool';
$Feed->description = '这是商城的优惠信息集合';
$Feed->items = $list;
$Feed->display();