Table of Contents (ToC) not always rendered

[targodan]

I wanted to add a ToC to some of my posts and found that it is not being rendered under certain circumstances.

My setup

Using the blackburn theme, added a shortcode called /layouts/shortcodes/toc.html:

<nav id="toc">
    {{ .Page.TableOfContents }}
</nav>

Added a post called /content/post/test.md:

+++
title = "Test"
+++

# ToC

{{% toc %}}

# a

a

# b

b

# c

c

Hugo version: Hugo Static Site Generator v0.16 BuildDate: 2016-09-01T17:43:30+02:00

The rendered result

When I just execute hugo like this

$ hugo -d public/

The ToC is not rendered / is empty.
The same thing happens when I execute hugo as a server.

$ hugo server

When executing as server and I modify and save the /layouts/shortcodes/toc.html it renders the ToC.
When I now change and save the /content/post/test.md again, the ToC disappears again.

Under any circumstances I did not get any errors.

By "does not render / is empty" I mean the result looks like this in the markup.

<nav id="toc">
</nav>

[stefano-pogliani]

I have a similar problem when trying to render the summary of other pages.

I use a taxonomy called pagesets to group pages and then I have a shortcode to render the list of pages in the taxonomy:

{{ $pageset := .Get 0 -}}
{{ $pages := .Site.Taxonomies.pagesets.Get $pageset }}

{{ range $pages }}
<div class="pageset-block">
  <h2>
    <a href="{{ .Page.RelPermalink }}">{{ .Page.LinkTitle }}</a>
  </h2>
  <p>{{ .Page.Summary }}</p>
</div>
{{ end }}

I am not familiar with the Go programming language but I was able to follow the build process to the following lines:

• Where (I believe) shortcodes are processed: https://github.com/spf13/hugo/blob/v0.17/hugolib/hugo_sites.go#L469
• Where (I believe) TOC, Content, and Summary are computed: https://github.com/spf13/hugo/blob/v0.17/hugolib/hugo_sites.go#L490

My use case is a sort of "index page" for the pages in the pageset.
As such I suspect that, for me, the shortcode in the "index page" is processed before the pages referenced in it are.

@targodan where you able to find a solution/work around for your problem?

[targodan]

@stefano-pogliani Sadly I wasn't, I just created the ToC by hand. 😒 . I have gathered a bit of experience with go. If I find the time I'll take a look at the code you found over the weekend.

[bep]

In Hugo 0.17 shortcodes are processed as late as possible -- but do not expect us to lift the laws of physics: We cannot create a summary for the page etc. before we have processed the shortcodes, a shortcode cannot list the content that surrounds it ... Use regular templates for these operations. I'm closing this now. This belongs on the discussion forum.

[targodan]

@bep I don't know about the summary problem but ToCs are a feature of hugo that does not work. Ergo this issue should not be closed.

In the name of being constructive: I looked at the code @stefano-pogliani found and were a bit confused by the order in which things are done. First shortcodes are handled and then the ToC is created. Unless I have not considered something important this contradicts your statement of "shortcodes are processed as late as possible".

Please take a look at my commit targodan/hugo@7473e32 I tested it and now the ToC in shortcode works. Yes, this propably means that shortcodes in headings might act weiredly (the next thing I will test) but now the ToC works. On the other hand, if not in shortcodes then where can we use the .Page.TableOfContents feature?

[targodan]

I opened a post in the discussion forum: https://discuss.gohugo.io/t/toc-not-working-in-shortcodes/4347

[bep]

I'll reopen this -- thinking about it this may be possible to do without too much work. But a PR that just moves some lines and "it works for me" will not be merged. Tests!

[targodan]

Of course. I only went for a quick shot without tests because you closed the issue and I didn't want to waste my time, not knowing if this will be reopened.

I will add some tests and then open a pull request. I hope to find the time over the weekend but can't promise anything, as I haven't looked at how you guys do your testing yet.

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.