Regular expression to convert label down to HTML

Question

How would you write a regex to convert labels to HTML? For example, you should enter the following:

This would be *italicized* text and this would be **bold** text 

Then it needs to be converted to:

 This would be <em>italicized</em> text and this would be <strong>bold</strong> text 

Very similar to the down label editing control used by stackoverflow.

Explanation

For what it's worth, I'm using C #. Also, these are the only tags I want to allow. The amount of convertible text will be less than 300 characters.

Answer 1

The best way is to find the version of the Markdown library ported to any language you use (you did not specify in your question).

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Now that you have clarified that you want STRONG and EM to be processed, and that you are using C #, I recommend that you take a look at Markdown. NET to see how these tags are implemented. As you can see, these are actually two expressions. Here is the code:

 private string DoItalicsAndBold (string text) { // <strong> must go first: text = Regex.Replace (text, @"(\*\*|__) (?=\S) (.+?[*_]*) (?<=\S) \1", new MatchEvaluator (BoldEvaluator), RegexOptions.IgnorePatternWhitespace | RegexOptions.Singleline); // Then <em>: text = Regex.Replace (text, @"(\*|_) (?=\S) (.+?) (?<=\S) \1", new MatchEvaluator (ItalicsEvaluator), RegexOptions.IgnorePatternWhitespace | RegexOptions.Singleline); return text; } private string ItalicsEvaluator (Match match) { return string.Format ("<em>{0}</em>", match.Groups[2].Value); } private string BoldEvaluator (Match match) { return string.Format ("<strong>{0}</strong>", match.Groups[2].Value); } 

Answer 2

One regex will not do. Each text markup will have its own html translator. Better see how existing converters are implemented to get an idea of ​​how this works.

http://en.wikipedia.org/wiki/Markdown#See_also

Answer 3

I don’t know about C # specifically, but in perl it will be:
s /
\ * \ * (. *?) \ * \ * /
\ & L; bold> $ 1 \ </ bold> / g
s /
\ * (. *?) \ * /
\ & L; EM> $ 1 \ </EM> / g

Answer 4

Check out this implementation of StackOverflow:

MarkdownSharp - Markdown for C #

Answer 5

I came across the following post which recommends not doing this. In my case, although I am looking for it to be simple, I thought I would send this to the jop recommendation in case someone wants to do this.