Question

I have the following html code, which have nesting up to level 3:

<div class="sp-wrap">
    <div class="sp-body" title="FAQ">
        Some text
        <div class="sp-wrap">
            <div class="sp-body" title="title1"> // Level 2
            Text1...
            </div>
        </div>
        <div class="sp-wrap">
            <div class="sp-body" title="title2"> // Level 2
            Text2...
            </div>
        </div>
        <div class="sp-wrap">
            <div class="sp-body" title="title3"> // Level 2
            Text3...
            <div class="sp-wrap">
                <div class="sp-body" title="title4"> // Level 3
                Text4...
                </div>
            </div>
        </div>
    </div>
</div>

I need to replace div tags into bbcode and my regular expression work only for not nested spoilers:

Regex.Replace(outstring, 
              @"<div class=""sp-body"" title=""(.*?)"">(.*?)</div>", 
              "[spoiler=$1]$2[/spoiler]", 
              RegexOptions.Singleline);

Answer 1

Did not test, but the idea should work:

string s1 = Regex.Replace(outstring, @"<div class=""sp-body"" title=""(.*?)"">", "[spoiler=$1]", RegexOptions.Singleline);
string s2 = Regex.Replace(s1, @"</div>", "[/spoiler]", RegexOptions.Singleline);

EDIT:

string s1 = Regex.Replace(outstring, @"<div class=""sp-wrap"">\s*<div class=""sp-body"" title=""(.*?)"">", "[spoiler=$1]", RegexOptions.Singleline);
string s2 = Regex.Replace(s1, @"</div>\s*</div>", "[/spoiler]", RegexOptions.Singleline);

Should produce something like

[spoiler=FAQ]
    Some text
    [spoiler=title1] // Level 2
        Text1...
        [/spoiler]
    [spoiler=title2] // Level 2
        Text2...
        [/spoiler]
    [spoiler=title3] // Level 2
        Text3...
        [spoiler=title4] // Level 3
            Text4...
            [/spoiler]
    [/spoiler]
</div>

As you can see it’s not perfectly indented (could be fixed, I guess) and detects one missing </div> in the example.