Php 简明教程

PHP - AJAX RSS Feed Example

Really Simple Syndication (RSS)

RSS（Really Simple Syndication 的缩写）可用于发布网站的经常更新信息，如音频、视频、图像等。我们可以使用 AJAX 和 PHP 将 RSS 提要集成到网站中。此代码演示了如何在我们的站点中显示 RSS 提要。

Index.html

索引页应如下所述 −

<html>
<head>
   <script>
      function showRSS(str) {
         if (str.length == 0) {
            document.getElementById("output").innerHTML = "";
            return;
         }

         if (window.XMLHttpRequest) {
            xmlhttp = new XMLHttpRequest();
         } else {
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
         }
         xmlhttp.onreadystatechange = function() {
            if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
               document.getElementById("output").innerHTML = xmlhttp.responseText;
            }
         }

         xmlhttp.open("GET","rss.php?q="+str,true);
         xmlhttp.send();
      }
   </script>
</head>
<body>
   <p>Please Select an option to get RSS:</p>
   <form>
      <select onchange = "showRSS(this.value)">
         <option value = "">Select an RSS-feed:</option>
         <option value = "cnn">CNN</option>
         <option value = "bbc">BBC News</option>
         <option value = "pc">PC World</option>
      </select>
   </form>
   <br>
   <div id = "output">RSS-feeds</div>
</body>
</html>

rss.php

“rss.php”中包含有关如何访问 RSS Feeds RSS 提要并将 RSS 提要返回到网页的语法。

<?php
   $q = $_GET["q"];

   if($q == "cnn") {
      $xml = ("http://rss.cnn.com/rss/cnn_topstories.rss");
   } elseif($q == "bbc") {
      $xml = ("http://newsrss.bbc.co.uk/rss/newsonline_world_edition/americas/rss.xml");
   } elseif($q = "pcw"){
      $xml = ("http://www.pcworld.com/index.rss");
   }

   $xmlDoc = new DOMDocument();
   $xmlDoc->load($xml);

   $channel = $xmlDoc->getElementsByTagName('channel')->item(0);

   $channel_title = $channel->getElementsByTagName('title')
   ->item(0)->childNodes->item(0)->nodeValue;

   $channel_link = $channel->getElementsByTagName('link')
   ->item(0)->childNodes->item(0)->nodeValue;

   $channel_desc = $channel->getElementsByTagName('description')
   ->item(0)->childNodes->item(0)->nodeValue;

   echo("<p><a href = '" . $channel_link . "'>" .
      $channel_title . "</a>");
   echo("<br>");
   echo($channel_desc . "</p>");

   $x = $xmlDoc->getElementsByTagName('item');

   for ($i = 0; $i<=2; $i++) {
      $item_title = $x->item($i)->getElementsByTagName('title')
      ->item(0)->childNodes->item(0)->nodeValue;

      $item_link = $x->item($i)->getElementsByTagName('link')
      ->item(0)->childNodes->item(0)->nodeValue;

      $item_desc = $x->item($i)->getElementsByTagName('description')
      ->item(0)->childNodes->item(0)->nodeValue;

      echo ("<p><a href = '" . $item_link . "'>" . $item_title . "</a>");
      echo ("<br>");
      echo ($item_desc . "</p>");
   }
?>

它将生成如下输出：

php rss feed example