Searching a String using C#

Question

I have the following String "</script><div id='PO_1WTXxKUTU98xDU1'></div>"

I require to get the attribute value from the div tag. How can i retrieve this using C#.

http://stackoverflow.com/questions/56107/what-is-the-best-way-to-parse-html-in-c ...and in-particular: http://stackoverflow.com/a/6244203/608764 — AlexFZ, Nov 01 '12 at 16:59

Anirudha · Answer 1 · 2012-11-01T17:37:35.760

1

Avoid parsing html with regex

Regex is not a good choice for parsing HTML files..

HTML is not strict nor is it regular with its format..

Use htmlagilityPack

You can do it like this with htmlagilityPack.

HtmlDocument doc = new HtmlDocument();
doc.Load(yourStream);
List<string> itemList = doc.DocumentNode.SelectNodes("//div[@id]")//selects all div having id attribute
.Select(x=>x.Attributes["id"].Value)//select the id attribute value
.ToList<string>();
//itemList will now contain all div's id attribute value

edited Nov 01 '12 at 17:37

answered Nov 01 '12 at 16:59

Anirudha

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Who said anything about regex? – Jon B Nov 01 '12 at 17:01
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@JonB he has tagged it with regex – Anirudha Nov 01 '12 at 17:02
So you think you're smart just because you know how to read? Pfft! – Jon B Nov 01 '12 at 17:03
@JonB u think tht u r smart..y not post ur own ans then..pffman – Anirudha Nov 01 '12 at 17:06
You don't need to shout "You cannot parse HTML with regex" Read this first http://stackoverflow.com/a/4234491/932418 – L.B Nov 01 '12 at 17:19
@L.B agreed but `regex` is not made for parsing html.it is used for regularly occurring things which is not in the case of html.. – Anirudha Nov 01 '12 at 17:21

score 0 · Answer 2 · answered Nov 01 '12 at 17:14

0

Strictly solving the question asked, one of a myriad ways of solving it would be to isolate the div element, parse it as an XElement and then pull the attribute's value that way.

        string bobo = "</script><div id='PO_1WTXxKUTU98xDU1'><!--DO NOT REMOVE-CONTENTS PLACED HERE--></div>";
        string justDiv = bobo.Substring(bobo.IndexOf("<div"));
        XElement xelem = XElement.Parse(justDiv);
        var id = xelem.Attribute("id");
        var value = id.Value;

There are certainly lots of ways to solve this but this one answers the mail.

answered Nov 01 '12 at 17:14

itsmatt

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i dnt think using linq2xml is a good way to solve this problem..specially if its html – Anirudha Nov 01 '12 at 17:15
Well, you're certainly allowed your opinion. It *does* answer the question though and doesn't take a dependency on another library to do it. – itsmatt Nov 01 '12 at 17:25

score 0 · Accepted Answer · answered Nov 05 '12 at 14:58

If you're a masochist you can do this old school VB3 style:

        string input = @"</script><div id='PO_1WTXxKUTU98xDU1'><!--DO NOT REMOVE-CONTENTS PLACED HERE--></div>";
        string startString = "div id='";

        int startIndex = input.IndexOf(startString);

        if (startIndex != -1)
        {
            startIndex += startString.Length;
            int endIndex = input.IndexOf("'", startIndex);
            string subString = input.Substring(startIndex, endIndex - startIndex);
        }

score -1 · Answer 4 · answered Nov 01 '12 at 17:02

A .NET Regex that looks something like this will do the trick

^</script><div id='(?<attrValue>[^']+)'.*$

you can then get hold of the value as

MatchCollection matches = Regex.Matches(input, @"^</script><div id='(?<attrValue>[^']+)'.*$");
if (matches.Count > 0)
{
    var attrValue = matches[0].Groups["attrValue"];
}

Searching a String using C#

4 Answers4