Document outline does not detect headings in the content when template-lock is used

[carolinan]

Description

When you edit a post an enable the option "Show template", the document outline displays the heading levels correctly.
But when you create or edit a page, where the template is shown by default, the document outline incorrectly says that there are no headings in the content. Heading blocks in the template show.

This was reported in #68684 (comment) but I could not find a dedicated issue for it.
Please close this if it is a duplicate :)

Step-by-step reproduction instructions

With Gutenberg trunk active, create a new page.
In the content, add a heading.
Open the Document outline.
Confirm that it is empty.

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure

[SainathPoojary]

Hi @carolinan,

I investigated the issue, and it seems to be related to the getBlocks function in Document Outline. While the post-content block has innerBlocks visible in the List View, it is returning an empty array in our case. This is why the Document Outline is unable to retrieve the heading blocks.

I also tried fetching innerBlocks using getBlocksByClientId, but even then, the post-content block returns empty innerBlocks.

[carolinan]

Yes I found the same.

[singhakanshu00]

Hi @carolinan for the solution, I was thinking of fetching the blocks from useEntityBlockEditor from @wordpress/core-data instead of getBlocks from blockEditorStore, and by doing this I solved the issue. Let me know if this will be a correct approach.

And for this additionally we need to fetch currentPostId and currentPostType from editorStore at this line.

gutenberg/packages/editor/src/components/document-outline/index.js

Line 118 in 06ee5e1

const { getEditedPostAttribute } = select( editorStore );

[carolinan]

I am not familiar with useEntityBlockEditor .
If you have a PR, please submit it and then I will work on something else, and unassign myself.
I picked this up only because I was already working on another enhancement for the document outline.

---

There is another issue, and a decision needs to be made about what the expected workflow is.

If the template has a heading, it is showing in the document outline even though it is not showing in the List View.
Clicking on the item in the outline does not select the block. So it works differently than anywhere else. Perhaps the item should not be clickable since it can't be edited.

[carolinan]

Perhaps the item should not be clickable since it can't be edited.

Coming back to this, my assumption is that we do want the headings that are in the template to show in this case, because of course they affect the heading level order and duplicate H1 count on the page.

[singhakanshu00]

Coming back to this, my assumption is that we do want the headings that are in the template to show in this case, because of course they affect the heading level order and duplicate H1 count on the page.

Now, this will be a little tricky with the approach I mentioned, as useEntityBlockEditor fetches block from the post content, but the heading in the template is not part of the post content.

Video shows useEntityBlockEditor fetches block that are in the post content, here only the heading that included in the content "a heading"

Screen.Recording.2025-01-22.at.1.58.27.PM.mov

[carolinan]

I did not understand what you wanted to show with the video, since it does not show the outline.

[carolinan]

Is there a reason not to combine the blocks from the template (the current getblocks) and the post content? Why would only one be used?

[Mamaduka]

I suggest we agree on the source of the heading blocks the Document Outline should display before proceeding to the solution.

[carolinan]

I tested the post one more time and I was wrong. The pages and posts behave the same way.

When the template shows they both show the headings that are in the template.
When the template is not showing they both show the headings that are in the post content.

So there is no bug with displaying the items.
There is a bug where the item is a button and clicking on it does nothing when "show template" is enabled.
There is a possible enhancement that involves listing headings from both, when "show template" is enabled.

[rinkalpagdar]

I think the document outline shows the correct headings, when "show template" is on it shows the headings of the template or else it will show the headings of the page content. Please correct me if I am wrong.

document-outline-headings.mp4

[carolinan]

That is how it is working today, yes.

And my perspective is that it defeats the purpose of the outline.

• The outline is not correct.
• It is not obvious that it is showing different headings, as we saw from the first report.
• The accessibility feature that presents the incorrect heading levels and duplicate H1's does not work since it does not show the result for the complete page that visitors see.
• It is confusing that when the template is showing, I can add and edit headings in the content and the outline does not change.