[AutoIdentifiers] Not created when rendering a MarkdownDocument

[hangar18rip]

Hi,

I get the following issue with the AutoIdentifierExtension.

Repro step

Using this code:

var pipeline = new MarkdownPipelineBuilder().UseAutoIdentifiers(AutoIdentifierOptions.GitHub).Build();
var input = "# Hey Isabelle, nice to meet you";

var res = Markdig.Markdown.ToHtml(input, pipeline);
Trace.TraceInformation(res);

var doc = Markdig.Markdown.Parse(input);
var res2 = Markdig.Markdown.ToHtml(doc, pipeline);
Trace.TraceInformation(res2);

It gives me this result:

res = <h1 id=\"hey-isabelle-nice-to-meet-you\">Hey Isabelle, nice to meet you</h1>\n
res2 = <h1>Hey Isabelle, nice to meet you</h1>\n

The content of res is the expected result.

Workaround

var doc = MarkdownParser.Parse(content, pipeline, null);

or

var doc = Markdig.Markdown.Parse(content, pipeline);

[MihaZupan]

You have to pass the pipeline to Markdown.Parse as well

[hangar18rip]

thanks @MihaZupan, I have it now but this was not very intuitive ;) Why should I pass the pipeline to both parse the document AND to render it. Maybe it can be a future improvment 😉

[xoofx]

I have it now but this was not very intuitive ;) Why should I pass the pipeline to both parse the document AND to render it. Maybe it can be a future improvement

The pipeline contains both the configured parsers and the configured renderers.

For the case of the auto-identifier extension, the extension hooks into existing parsers.

markdig/src/Markdig/Extensions/AutoIdentifiers/AutoIdentifierExtension.cs

Lines 35 to 51 in 5f80d86

	public void Setup(MarkdownPipelineBuilder pipeline)
	{
	var headingBlockParser = pipeline.BlockParsers.Find<HeadingBlockParser>();
	if (headingBlockParser != null)
	{
	// Install a hook on the HeadingBlockParser when a HeadingBlock is actually processed
	headingBlockParser.Closed -= HeadingBlockParser_Closed;
	headingBlockParser.Closed += HeadingBlockParser_Closed;
	}
	var paragraphBlockParser = pipeline.BlockParsers.FindExact<ParagraphBlockParser>();
	if (paragraphBlockParser != null)
	{
	// Install a hook on the ParagraphBlockParser when a HeadingBlock is actually processed as a Setex heading
	paragraphBlockParser.Closed -= HeadingBlockParser_Closed;
	paragraphBlockParser.Closed += HeadingBlockParser_Closed;
	}
	}

In that case, the renderer is not modified (because the heading renderer is registered by default), but for others, they require to register their renderers as well:

markdig/src/Markdig/Extensions/Abbreviations/AbbreviationExtension.cs

Lines 15 to 26 in 5f80d86

	public void Setup(MarkdownPipelineBuilder pipeline)
	{
	pipeline.BlockParsers.AddIfNotAlready<AbbreviationParser>();
	}
	public void Setup(MarkdownPipeline pipeline, IMarkdownRenderer renderer)
	{
	if (renderer is HtmlRenderer htmlRenderer && !htmlRenderer.ObjectRenderers.Contains<HtmlAbbreviationRenderer>())
	{
	// Must be inserted before CodeBlockRenderer
	htmlRenderer.ObjectRenderers.Insert(0, new HtmlAbbreviationRenderer());
	}