HtmlRenderer seems to ignore setting GENERATE_HEADER_ID in some cases

[travkin79]

I am not sure if I observe a bug or if it is desired behavior.

I'm using the Markdown parser and HTML renderer with the following settings (besides others):

• GENERATE_HEADER_ID=false
• RENDER_HEADER_ID=true
• AttributesExtension activated

I expect:
If I explicitly set header IDs in headings, they will be rendered, but no IDs will be generated for headings that do not have any headings ID in Markdown source code. For example:

# Heading 1

## Images {#section-images}

should become

<h1>Heading 1</h1>
<h2 id="section-images">Images</h2>

Instead I see:
If I explicitly set header IDs in headings, they will be rendered. If they are not set, they will be generated and rendered, too. For the example from above, we'll get:

<h1 id="heading-1">Heading 1</h1>
<h2 id="section-images">Images</h2>

Do I misunderstand something or is that a bug?

I traced down the source code to the following statement in com.vladsch.flexmark.html.HtmlRenderer#MainNodeRenderer:

this.htmlIdGenerator = htmlIdGeneratorFactory != null ? htmlIdGeneratorFactory.create(this)
                    : (!(htmlOptions.renderHeaderId || htmlOptions.generateHeaderIds) ? HtmlIdGenerator.NULL : new HeaderIdGenerator.Factory().create(this));

I think, an ID generator should only be created if the generateHeaderIds settings is active and should be independent from the renderHeaderId setting. Do you agree?

[vsch]

@travkin79, it is a left-over from legacy implementation. You are right the htmlOptions.renderHeaderId should not be used in the test.

I will be addressing all the accumulated PR's and bugs in the next couple of weeks.

[travkin79]

Thank you for the quick answer, @vsch. I've prepared a pull request #566 to fix that.

[travkin79]

Hi @vsch,
There still seems to be a problem or I misunderstand something.

I'm using flexmark 0.64.6 now and I'm having

• GENERATE_HEADER_ID=false
• RENDER_HEADER_ID=true
• AttributesExtension activated

I have a use case, where I want to render something like
## Images {#section-images}

When debugging, I see

• the HtmlRenderer uses an HtmlIdGenerator in HtmlRenderer#getNodeId(Node)
• the HtmlIdGenerator does return null (I think, because I have GENERATE_HEADER_ID=false)
• the current Node's anchorRefId attribute is correctly set to section-images what I expected to be the ID to be rendered
• the HtmlRenderer#getNodeId(Node) method does not read the Node's anchorRefId attribute and returns null instead
• the CoreNodeRenderer#render(Heading, NodeRendererContext, HtmlWriter) method doesn't read the Node's anchorRefId attribute either

Shouldn't the Node's anchorRefId attribute be used as an ID in this case?

The final result is something I wouldn't expect with these settings, a heading without any ID:
<h2>Images</h2>

By the way, I also tried using flexmark 0.64.8, but I couldn't read the flexmark-java-0.64.8.zip sources file. It seems to be corrupt.

Best regards,
Dietrich

[travkin79]

Hi @vsch,
I found the time to create a pull request with a unit test to reproduce my situation and with a bug fix (see pull request #581). Could you please review and merge the bug fix?

Thank you and best regards.
Dietrich

[travkin79]

Hi @vsch,
Is there any update on that?
Best regards.
Dietrich