RoundtripRenderer and YamlFrontMatterRenderer

[mnaoumov]

If I have a markdown file my-awesome.md

---
title: Hello world
---

My awesome **markdown**

which I want to edit programatically

var pipeline
    = new MarkdownPipelineBuilder()
        .UseYamlFrontMatter()
        .EnableTrackTrivia()
        .Build();

var md = File.ReadAllText("my-awesome-md");
var document = Markdown.Parse(md, pipeline);

var sw = new StringWriter();
var rr = new RoundtripRenderer(sw);
rr.ObjectRenderers.Add(new YamlFrontMatterRenderer()); // this line doesn't change anything
rr.Write(document);
Console.WriteLine(sw.ToString());

it outputs

title: Hello world

My awesome **markdown**

with --- removed around yaml frontmatter

[mnaoumov]

Got it fixed via

rr.ObjectRenderers.Insert(0, new MyYamlFrontMatterRenderer()); // it's important to insert it before CodeBlockRenderer

public class MyYamlFrontMatterRenderer : MarkdownObjectRenderer<RoundtripRenderer, YamlFrontMatterBlock>
{
    private readonly CodeBlockRenderer _codeBlockRenderer;

    public MyYamlFrontMatterRenderer()
    {
        _codeBlockRenderer = new CodeBlockRenderer();
    }

    protected override void Write(RoundtripRenderer renderer, YamlFrontMatterBlock obj)
    {
        renderer.Writer.WriteLine("---");
        _codeBlockRenderer.Write(renderer, obj);
        renderer.Writer.WriteLine("---");
    }
}