PHP和AJAX的RSS阅读器 -php手册-php.cn

Home

php教程

php手册

PHP和AJAX的RSS阅读器

WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB

May 25, 2016 pm 04:41 PM

ajaxphp

PHP和AJAX的RSS阅读器,RSS阅读器是用来读取RSS信息,允许快速的RSS浏览新闻和更新.

AJAX的RSS阅读器:在AJAX以下例子,我们将展示一个RSS阅读器的内容从RSS是载入网页无需刷新.

在HTML表单:这是HTML网页,它包含一个简单的HTML表格,并链接到一个JavaScript:

<html> 
<head> 
<script type="text/javascript" src="getrss.js"></script> 
</head> 
<body><form>  
Select an RSS-Feed: 
<select onchange="showRSS(this.value)"> 
<option value="Google">Google News</option> 
<option value="MSNBC">MSNBC News</option> 
</select> 
</form><p><div id="rssOutput"> 
<b>RSS Feed will be listed here.</b></div></p> 
</body> 
</html>

例如解释-的H TML表单正如你可以看到,HTML网页上面载有一个简单的HTML表单的下拉框,作品的形式像这样,事件触发时,用户选择一个选项在下拉框中当事件触发的功能要求showRSS ()被处决,下面的形式是一个

所谓的" rssOutput ",这是作为一个占位符返回的数据showRSS ()函数的JavaScript,JavaScript代码是储存在" getrss.js "和相关的HTML文件:

var xmlHttp
function showRSS(str) {
    xmlHttp = GetXmlHttpObject()
        if (xmlHttp == null) {
            alert("Browser does not support HTTP Request")
            return
        }
        var url = "getrss.php"
        url = url + "?q=" + str
        url = url + "&sid=" + Math.random()
        xmlHttp.onreadystatechange = stateChanged
        xmlHttp.open("GET", url, true)
        xmlHttp.send(null)
}
function stateChanged() {
    if (xmlHttp.readyState == 4 || xmlHttp.readyState == "complete") {
        document.getElementById("rssOutput")
        .innerHTML = xmlHttp.responseText
    }
}
function GetXmlHttpObject() {
    var xmlHttp = null;
    try {
        // Firefox, Opera 8.0+, Safari
        xmlHttp = new XMLHttpRequest();
    } catch (e) {
        // Internet Explorer
        try {
            xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
    }
    return xmlHttp;
}

例如解释该stateChanged ()和GetXmlHttpObject职能是一样的PHP的AJAX推荐的篇章,该showRSS ()函数每一次的选择是选择在输入外地执行这一职能如下:界定了网址（档）传送给服务器添加一个参数（ Q ）的网址与选定的选项从下拉框中添加一个随机数字,以防止服务器使用快取档案,吁请GetXmlHttpObject函数创建一个XMLHTTP物件,并讲述了对象执行的功能要求时stateChanged变化是触发开幕XMLHTTP物件与特定网址,发送一个HTTP请求到服务器,PHP页面网页服务器要求的JavaScript代码是一个PHP文件名为"getrss.php" :

<?php
//get the q parameter from URL
$q = $_GET["q"];
//find out which feed was selected
if ($q == "Google") {
    $xml = ("http://news.phprm.com/news?ned=us&topic=h&output=rss");
} elseif ($q == "MSNBC") {
    $xml = ("http://rss.msnbc.msn.com/id/3032091/device/rss/rss.xml");
}
$xmlDoc = new DOMDocument();
$xmlDoc->load($xml);
//get elements from "<channel>"
$channel = $xmlDoc->getElementsByTagName(&#39;channel&#39;)->item(0);
$channel_title = $channel->getElementsByTagName(&#39;title&#39;)->item(0)->childNodes->item(0)->nodeValue;
$channel_link = $channel->getElementsByTagName(&#39;link&#39;)->item(0)->childNodes->item(0)->nodeValue;
$channel_desc = $channel->getElementsByTagName(&#39;description&#39;)->item(0)->childNodes->item(0)->nodeValue;
//output elements from "<channel>"
echo ("<p><a href=&#39;" . $channel_link . "&#39;>" . $channel_title . "</a>");
echo ("<br />");
echo ($channel_desc . "</p>");
//get and output "<item>" elements
$x = $xmlDoc->getElementsByTagName(&#39;item&#39;);
for ($i = 0; $i <= 2; $i++) {
    $item_title = $x->item($i)->getElementsByTagName(&#39;title&#39;)->item(0)->childNodes->item(0)->nodeValue;
    $item_link = $x->item($i)->getElementsByTagName(&#39;link&#39;)->item(0)->childNodes->item(0)->nodeValue;
    $item_desc = $x->item($i)->getElementsByTagName(&#39;description&#39;)->item(0)->childNodes->item(0)->nodeValue;
    echo ("<p><a href=&#39;" . $item_link . "&#39;>" . $item_title . "</a>");
    echo ("<br />");
    echo ($item_desc . "</p>");
}
?>

本文地址：

转载随意，但请附上文章地址:-)

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn