连接数据库，动态生成Rss feed(订阅号)

首先要把xml模板建好，该xml模板与普通的xml模板不同，需要加上rss输出模板，具体代码如下：

<?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>

接下来 写个类，完成动态创建xml节点信息，憋说话，看代码：
class feed {
public $title = ''; // channel的title
public $link = ''; // channel的link
public $description = ''; // channel的descrip
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; charset=utf-8");
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
// $list是商品列表，是二维数组，每一行是一个商品
protected function addItem($list) {
foreach($list as $goods) {
$this->rss->appendChild($this->createItem($goods));
}
}

// 封装一个方法，用来造item
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;
}
}

类写好，就拿数据吧，连接数据库，拿数据：

$conn = mysql_connect('localhost','root','111111');
mysql_query('set names utf8',$conn);
mysql_query('use boolshop',$conn);

$sql = 'select goods_name as title,goods_brief as description from goods order by add_time desc limit 8';

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

$list = array();

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

配置变量，输出xml信息：
$feed = new feed();
$feed->title = '正装品牌';
$feed->link = 'http://localhost/0424';
$feed->description = '这是正装品牌的最新优惠信息';
$feed->items = $list;
$feed->display();

最终显示效果：