I have a simple requirement to extract text in html. Suppose the html is
<h1>hello</h1> ... <img moduleType="calendar" /> ...<h2>bye</h2>
I want to convert it into three parts
<h1>hello</h1>
<img moduleType="calendar" />
<h2>bye</h2>
The aim is to extract text in two categories, simple html and special tags with <img moduleType="Calendar".
Don't do that; HTML can be broken in many beautiful ways. Use beautiful soup instead.
It depends on the language and context you are using. I do something similar on my CMS, my approach is first find tags and then attributes.
Get tags
"<img (.*?)/>"
Then I search through the result for specific attributes
'title="(.*?)"'
If you want to find all attributes you could easily change the explicit title to the regex [a-z], or non-whitespace character, and then loop through those results as well.
I actually try to do similar thing as asp.net compiler to compile the mark up into server control tree, regular expression is heavily used by asp.net compiler. I have a temporary solution, although not nice, but seems ok.
//string source = "<h1>hello</h1>";
string source = "<h1>hello<img moduleType=\"calendar\" /></h1> <p> <img moduleType=\"calendar\" /> </p> <h2>bye</h2> <img moduleType=\"calendar\" /> <p>sss</p>";
Regex exImg = new Regex("(.+?)(<img.*?/>)");
var match = exImg.Match(source);
int lastEnd = 0;
while (match.Success)
{
Console.WriteLine(match.Groups[1].Value);
Console.WriteLine(match.Groups[2].Value);
lastEnd = match.Index + match.Length;
match = match.NextMatch();
}
Console.WriteLine(source.Substring(lastEnd, source.Length - lastEnd ));