CODEWITHSUNDEEP
c#htmlregex
JadedEric
JadedEric

Reputation: 2073

replace string regex

I'm trying to give users the ability to "mark" certain sections of content in a CMS with some additional 'tags' if you will, that will then get translated, for example, bold, when the content is rendered on the page.

Something like {strong:Lorum ipsum dolar} where the text will then be wrapped with <strong>Lorum ipsum dolar</strong>.

I've tried to figure the regex out for this, but I'm no good. I grabbed some html replacement scripts from sites, by they are not very helpful, at least, I don't know what to change :$.

Any help would be appreciated.

note

I'm doing this in C#.

Upvotes: 1

Views: 181

Answers (3)

FlyingStreudel
FlyingStreudel

Reputation: 4464

So this will get you the tags and parts you are looking for, however, the way I turn those results into the final string is pretty ugly. Its really just the regex at the top that matters. Enjoy!

string test = "{strong:lorem ip{i:su{b:m}m}m dolar} {strong:so strong}";
Regex tagParse = new Regex(
    @"\{(?<outerTag>\w*)
        (?>
            (?<DEPTH>\{(?<innerTags>\w*))
            |
            (?<-DEPTH>\})
            |
            :?(?<innerContent>[^\{\}]*)
        )*
        (?(DEPTH)(?!))

        ", RegexOptions.IgnorePatternWhitespace | RegexOptions.Singleline);

MatchCollection matches = tagParse.Matches(test);
foreach (Match m in matches)
{
    StringBuilder sb = new StringBuilder();
    List<string> tags = new List<string>();
    tags.Add(m.Groups["outerTag"].Value);
    foreach (Capture c in m.Groups["innerTags"].Captures)
        tags.Add(c.Value);
    List<string> content = new List<string>();
    foreach (Capture c in m.Groups["innerContent"].Captures)
        content.Add(c.Value);
    if (tags.Count > 1)
    {
        for (int i = 0; i < content.Count; i++)
        {
            if (i >= tags.Count)
                sb.Append("</" + tags[tags.Count - (i - tags.Count + 1)] + ">");
            else
                sb.Append("<" + tags[i] + ">");
            sb.Append(content[i]);
        }
        sb.Append("</" + tags[1] + ">");
    }
    else
    {
        sb.Append("<" + tags[0] + ">");
        sb.Append(content[0]);
    }
    sb.Append(m.Groups["outerContent"].Value);
    sb.Append("</" + m.Groups["outerTag"].Value + ">");
    Console.WriteLine(sb.ToString());
}

Upvotes: 1

detale
detale

Reputation: 12892

Edit: To work with nested tags, multiple matches per input string. Restrictions: text inside a tag pair cannot contain "{" or "}".

private string FormatInput(string input)
{
    const string patternNonGreedy = @"\{(?<tag>.+?):(\s*)(?<content>.*?)(\s*)}";
    const string patternGreedy = @"\{(?<tag>.+?):(\s*)(?<content>.*)(\s*)}";

    Match mtc = Regex.Match(input, patternGreedy);
    if (!mtc.Success)
        return input;

    string content = mtc.Groups["content"].Value;
    int braces = 0;
    foreach (char c in content)
    {
        if (c == '{')
            braces++;
        else if (c == '}')
        {
            if (braces > 0)
                braces--;
        }
    }

    if (braces == 0)
        return input.Substring(0, mtc.Index)
            + string.Format("<{0}>{1}</{0}>", mtc.Groups["tag"].Value, FormatInput(content))
            + input.Substring(mtc.Index + mtc.Length);

    mtc = Regex.Match(input, patternNonGreedy);
    Debug.Assert(mtc.Success);

    content = mtc.Groups["content"].Value;
    return input.Substring(0, mtc.Index)
        + string.Format("<{0}>{1}</{0}>", mtc.Groups["tag"].Value, content)
        + FormatInput(input.Substring(mtc.Index + mtc.Length));
}

Test examples:

string output1 = FormatInput("{strong:Lorum ipsum dolar}");
// output1: <strong>Lorum ipsum dolar</strong>

string output2 = FormatInput("{strong:{italic:Lorum ipsum dolar}}");
// output2: <strong><italic>Lorum ipsum dolar</italic></strong>

string output3 = FormatInput("{strong:Lor{i:e}m ipsum dol{i:o}r}");
// output3: <strong>Lor<i>e</i>m ipsum dol<i>o</i>r</strong>

Upvotes: 0

Samy Arous
Samy Arous

Reputation: 6814

This looks a lot like jSon to XML conversion. 

{"strong":"Lorum ipsum dolar"}

would become 

<strong>Lorum ipsum dolar</strong>

and 

{"strong":{italic:"Lorum ipsum dolar"}}

would become 

<strong>
<italic>Lorum ipsum dolar</italic>
</strong>

I'm not saying this is the answer, but you might wanna look over that. The basic idea, would be to parse your tags into a hierarchical struct then parse it back to HTML or whatever output language you use.

Upvotes: 1

Related Questions