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使用XPath查找所有JavaScript类型脚本元素

html-agility-pack xpath linq c#

Christer Johansson · 技术社区 · 7 年前

我想找到所有 <script> 使用HTML agility pack(加上LINQ和XPath)在一系列HTML文档中添加元素。这些文档的页眉中有脚本元素,页脚中有谷歌分析。首先,我尝试以头脚本为目标并删除它们。我的记事本++显示我有719个脚本元素,但我的控制台应用程序只找到其中的55个。

我需要som帮助来正确定位它们,以便从文档中删除它们。

源文件(头部结构),

<!doctype html system "html.dtd">
<html>
<head>
<link rel="stylesheet" href="../IRstyle.css" type="text/css">
<title>Non-hierarchic document clustering</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="keywords" content="">
<meta name="VW96.objecttype" content="Document">

<script language="JavaScript" type="text/JavaScript">
//Javascript-code goes here
</script>
</head>
<body>    
<!--Body contents goes here-->

<!-- in footer -->
<script src="http://www.google-analytics.com/urchin.js" type="text/javascript">
</script>
<script type="text/javascript">
_uacct = "UA-67XXXX-X";
urchinTracker();
</script>
</body>
</html>

到目前为止,我已经尝试使用JavaScript来定位“语言”类型,但在解析html/head时只得到了一些点击。我的方法从列表中获取文件名。现在,该方法打印出列表中收集的脚本数,这将更改为“脚本”。删除();'一旦我找到正确的搜索字符串。

private static void FindTagsToRemove(IEnumerable<string> files)
{
    var doc = new HtmlDocument();
    List<string> scripts = new List<string>();
    List<string> errors = new List<string>();
    try
    {
        foreach (var file in files)
        {
            doc.Load(@file);
            var head = doc.DocumentNode.SelectSingleNode("html/head");
            var nodes = new List<HtmlNode>();
            bool isScript = false;

            foreach (var node in head.ChildNodes.ToList())
            {
                if (node.NodeType == HtmlNodeType.Element && node.Name.Contains("script"))
                {
                    isScript = !isScript;
                    scripts.Add(node.OuterHtml);
                    Console.WriteLine(node.OuterHtml);
                }
                else if (isScript)
                {
                    nodes.Add(node);
                    node.Remove();
                }
            }
        }
        int nr_scripts = scripts.Count();
        Console.WriteLine("Number of scripts in collection: {0}", nr_scripts);
    }
    catch (Exception Ex)
    {
        Console.WriteLine(Ex.Message);
    }
}

如果有人有更好的方法来定位head节点中的JavaScripts,我们将不胜感激。感谢您的帮助!:)

1 回复 | 直到 7 年前

kuujinbo 7 年前

如果你只需要 <script> 元素节点,使用 descendant-or-self ( // ) . 示例HTML:

var html =
@"<!doctype html system 'html.dtd'>
<html>
<head>
<link rel='stylesheet' href='../IRstyle.css' type='text/css'>
<title>Non-hierarchic document clustering</title>
<meta http-equiv='Content-Type' content='text/html; charset=iso-8859-1'>
<meta name='keywords' content=''>
<meta name='VW96.objecttype' content='Document'>
<script language='JavaScript' type='text/JavaScript'>
//Javascript-code goes here
</script>
</head>
<body>    
<!--Body contents goes here-->

<!-- in footer -->
<script src='http://www.google-analytics.com/urchin.js' type='text/javascript'>
</script>
<script type='text/javascript'>
_uacct = 'UA-67XXXX-X';
urchinTracker();
</script>
</body>
</html>";

分析示例:

var document = new HtmlDocument();
document.LoadHtml(html);
// target only <script> in <head>
// var scriptTags = document.DocumentNode.SelectNodes("//head/script");
var scriptTags = document.DocumentNode.SelectNodes("//script");

foreach (var script in scriptTags) script.Remove();    

document.Save(OUTPUT);

输出:

<!doctype html system 'html.dtd'>
<html>
<head>
<link rel='stylesheet' href='../IRstyle.css' type='text/css'>
<title>Non-hierarchic document clustering</title>
<meta http-equiv='Content-Type' content='text/html; charset=iso-8859-1'>
<meta name='keywords' content=''>
<meta name='VW96.objecttype' content='Document'>

</head>
<body>    
<!--Body contents goes here-->

<!-- in footer -->


</body>
</html>