C# Regex extract HTML text

Question

I have a HTML string that I just want the text from:

string html = "<span class="MyText" id="1">     SomeText blah blah</span>";

So I use the following expression:

public static string StripHTMLTags(string source)
{
    return Regex.Replace(source, "<.*?>", string.Empty);
}

But sometimes the HTML string contains several lines of HTML:

string html = "<span class="MyText" id="1">SomeText blah blah</span<br><span class="MyText" id="2">SomeText blah blah 1</span><br><span class="MyText" id="2">SomeText blah blah2</span>";

So now I want to extract out the text that is between the <span> tags and store them in a list or array or lines.

NOTE: I am parsing custom HTML that will only have two tags the break and span tags.

How can I do this using Regex?

HTML is not regular enough to be parsed with regular expressions ;) — Paweł Dyl, Sep 06 '16 at 11:23
My application is a C# windows application that receives HTML text from a server. — Harry Boy, Sep 06 '16 at 11:29

score 1 · Answer 1 · edited Nov 24 '17 at 21:31

1

Parsing HTML with Regex is cumbersome and errorprone. Have a look at the rather famous StackOverflow post RegEx match open tags except XHTML self-contained tags.

I suggest to use a library for that. One that is widely used is the Html Agility Pack at http://html-agility-pack.net available via Nuget.

EDIT:

In order to get the inner text of HTML you can use something like this:

var pageDoc = new HtmlDocument();
pageDoc.LoadHtml(pageContent);
var pageText = pageDoc.DocumentNode.InnerText;

edited Nov 24 '17 at 21:31

wp78de

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answered Sep 06 '16 at 11:24

Ralf Bönning

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I am parsing custom HTML that will only have two tags
and – Harry Boy Sep 06 '16 at 11:26
@HarryBoy - this may change over time. I have a sample added to the post. I think the code is easier to understand than a RegEx-Expression that can get rather complicated. – Ralf Bönning Sep 06 '16 at 11:29

score 0 · Answer 2 · answered Sep 06 '16 at 11:28

0

I don't know if you can solve this with a different REGEX statement (just don't know much about regular expressions), but what you could do is split the string every time a "><" occurs and then extract the text of each of those substrings.

Also http://regexr.com/ might help you trying different statements.

Edit: Is there always a '< br>' after a '< /span>' ?

answered Sep 06 '16 at 11:28

Djindjidj

133
8

No there is not always a '
', only when there are several lines received is there a '
' – Harry Boy Sep 06 '16 at 11:35

score 0 · Answer 3 · answered Sep 06 '16 at 11:54

Beware if running in non-private application. As I said:

HTML is not regular enough to be parsed with regular expressions

However, this simple HTML snippets can be parsed with following one:

string txt =
    @"""<span class=""MyText"" id=""1"">SomeText blah blah</span<br><span class=""MyText"" id=""2"">SomeText blah blah 1</span><br><span class=""MyText"" id=""2"">SomeText blah blah2</span>""";

var matches = Regex.Matches(txt, "(?<=>)([^<]+)(?=<)");
foreach (Match match in matches)
    Console.WriteLine(match.Value);

It yields:

SomeText blah blah
SomeText blah blah 1
SomeText blah blah2

C# Regex extract HTML text

3 Answers3