Extensibilty

[mstijak]

I'm looking to replace Markdown.Deep with CommonMark.NET on a documentation project I'm working on.

Critical thing I found missing is the ability to process relative urls.
For example, I would like to replace ~/ with application path.

Other thing I would like to see is support for strikethrough syntax using (~~) and other GitHub flavor extensions.

Is there a plan for adding such features?

I would love to help.

[Knagis]

Support for ~/seems to be very logical since this is a .NET library so it is very likely that such a feature would often be required. This might be built-in rather soon - but could you add it as a separate issue specifically? Currently this can be resolved with the code provided below.

Other features that involve creation of new inline types such as ~~aa~~ will not be possible without modifying the source code - at least currently I do not plan to add support for this kind of extensibility in fears that the mechanism can significantly lower performance. That said, I will most likely implement the more popular extensions (turned off by default until the specification defines them). The main roadblock for this is commonmark/commonmark-spec#154 - once the general approach for overlapping inlines is resolved, the most common extensions can be implemented.

Now the code to resolve relative urls in the current version:

        using (var reader = new StringReader("foo **[a](~/temp)** [b][c] \r\n\r\n[c]: ~/bar"))
        using (var writer = new StringWriter())
        {
            // parse blocks
            var doc = CommonMarkConverter.ProcessStage1(reader);

            // parse inlines
            CommonMarkConverter.ProcessStage2(doc);

            // process syntax tree
            HandleRelativeUrl(doc);

            // write html
            CommonMarkConverter.ProcessStage3(doc, writer);
            // <p>foo <strong><a href="/app/dir/temp">a</a></strong> <a href="/app/dir/bar">b</a></p>
        }

    private static void HandleRelativeUrl(Syntax.Block block)
    {
        if (block.InlineContent != null)
            HandleRelativeUrl(block.InlineContent);

        var b = block.FirstChild;
        if (b != null)
            HandleRelativeUrl(b);

        b = block.NextSibling;
        while (b != null)
        {
            HandleRelativeUrl(b);
            b = b.NextSibling;
        }
    }

    private static void HandleRelativeUrl(Syntax.Inline inline)
    {
        if (inline.Linkable != null)
            inline.Linkable.Url = ResolveUrl(inline.Linkable.Url);

        var i = inline.FirstChild;
        if (i != null)
            HandleRelativeUrl(i);

        i = inline.NextSibling;
        while (i != null)
        {
            HandleRelativeUrl(i);
            i = i.NextSibling;
        }
    }

[mstijak]

Thanks for the quick and detailed response. I have created a new issue #5.

[mstijak]

Hate to bother you on the old issue, but as I see that commonmark/commonmark-spec#154 is fixed, I cannot help myself and have to ask if there are any plans to add extensibilty options?
That's the only thing I find missing in this incredible Markdown implementation.

[Knagis]

@mstijak - Strikethrough is now implemented as a configurable feature (see 8ec7e22). I will publish the new version to nuget as soon as 0.14 version of the spec is released.

Note that there is a difference on how ~~~~foo~~~~ works on GitHub and in this implementation (I followed the same approach as with ****foo**** and render nested <del><del>foo</del></del>.

[mstijak]

I missed that strike-through support is already in. Thanks and keep up the good work.

[Knagis]

It wasn't. It was implemented yesterday.

-------- Original Message --------
From: Marko Stijak notifications@github.com
Sent: Monday, December 29, 2014 10:47 AM
To: "Knagis/CommonMark.NET" CommonMark.NET@noreply.github.com
Subject: Re: [CommonMark.NET] Extensibilty (#4)
CC: Kārlis Gaņģis knagis@miga.lv

I missed that strike-through support is already in. Thanks and keep up the good work.

---

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