westdc-zf1/application/models/PingbackRpc.php

<?php
class PingbackRpc
{
	private $BLOCK_ELEMENTS = array("div", "p", "body", "ul", "ol", "td", "pre", "center");
	private $CONTEXT_BYTES = 200;

  	 /**
  	  * ping method for pingback xmlrpc server
  	  *
  	  * @param string $externalURI The absolute URI of the post on the source page containing the link to the target site.
  	  * @param string $westdcURI The absolute URI of the target of the link, as given on the source page.
  	  * @return string or int ping status
  	  */
	public function ping($externalURI,$westdcURI)
	{
		//调试
		$writer = new Zend_Log_Writer_Stream('pingback.log');
		$logger = new Zend_Log($writer);
		$logger->info('Informational message');
		$logger->info('extern url:'.$externalURI);
		//判断uuid
		$uuid=explode('/',$westdcURI);
		$uuid=$uuid[count($uuid)-1];
		$db=Zend_Registry::get('db');
		$sql="select count(*) as count from metadata where uuid=?";
		$rs=$db->fetchRow($sql,array($uuid));
		//不存在此数据
		if ($rs['count']==0) return false;
		//anti-spam
		//来源地址和用户发送的IP地址相同
		$ip=$_SERVER['REMOTE_ADDR'];
		$p=parse_url($externalURI);
		$ip1=gethostbyname($p['host']);
		$logger->info('user ip:'.$ip);
		//if ($ip<>$ip1) return false;
		// 限制：来源中包含目标地址
		$i = new Zend_Http_Client($externalURI);
		$j = $i->request(Zend_Http_Client::GET);
		// RETURN: our source blog post does not exist on remote server
		if (($pos = strpos(($externalURIBody = $j->getBody()), $westdcURI)) === false) 
		{
			return false;
		}
		//获取标题和内容
		// get the title of the remote blog post
		preg_match('/<title>([^<]*?)<\/title>/is', $externalURIBody, $titles);
		$title = $titles[1];
		unset($titles);
		// RETURN: no title on page
		if ($title == null) {
		    return false;
		}
		//limit title length?
		$title=(mb_strlen($title)>100)?mb_substr($title,0,99):$title;
		$agent=$_SERVER['HTTP_USER_AGENT'];
		$logger->info('title:'.$title);
		$logger->info('user agent:'.$agent);
		$contents = $j->getBody();
		$dom = new DOMDocument();
		@$dom->loadHTML($contents);
		$xml = @simplexml_import_dom($dom);
		$path = "//body//a[@href=\"$westdcURI\"][1]";
		$link = $this->xpath1($xml, $path);
		$context = $link;
		// Searching for the smallest block element containing the link
		while (! in_array(strtolower($context->getName()), $this->BLOCK_ELEMENTS)) {
			$path .= "/..";
			$context = $this->xpath1($xml, $path);
		}
		// Expanding context
		$previous = $this->xpath1($xml, "$path/preceding-sibling::*[position()=1]");
		$next = $this->xpath1($xml, "$path/following-sibling::*[position()=1]");
		// Join this all
		$ret = "";
		if ($previous) {
			$ret = $previous->asXML();
		}
		$ret .= " " . $context->asXML() . " ";
		if ($next) {
			$ret .= " " . $next->asXML();
		}

		$ret = preg_replace('/[\s|\r|\n]+/im', ' ', $ret);
		$ret = preg_replace('/ <(h1|h2|h3|h4|h5|h6|p|th|td|li|dt|dd|pre|caption|input|textarea|button|body|borrowed|from|wordpress)[^>]*>/is', ' ', $ret);
		$stripper = new Zend_Filter_StripTags('a', 'href');
		$ret = $stripper->filter($ret);
		$logger->info($ret);
		//保存到数据库，最多只保留一个PINGBACK?
		$sql="insert into comments (type,author,url,ip,content,agent,uuid) values('pingback',?,?,?,?,?,?)";
		$db->query($sql,array($title,$externalURI,$ip,$ret,$agent,$uuid));
		return "OK";
	}
	/**
	 * Queries SimpleXMLElement with XPath and return the first result or null if found nothing
	 *
	 * @param SimpleXMLElement $dom SimpleXMLElement object to query
	 * @param string $xpath the query
	 * @return SimpleXMLElement | null resulting element 
	 */
	private function xpath1($dom, $xpath) {
		$res = $dom->xpath($xpath);
		if (count($res) < 1) {
			return null;
		}
		return $res[0];
	}	
}
?>