fix(v2): unify anchor behavior

[lex111]

Motivation

First of all, remove large margin on all screens (see test plan) when following a link from anchor. Further, when you open the referenced link in the browser, the header is automatically hidden, similarly when switching to another anchor on this page.

Have you read the Contributing Guidelines on pull requests?

Yes

Test Plan

Prerequisite: open link with anchor, eg https://v2.docusaurus.io/docs/installation#project-structure

Before	After

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[lex111]

@yangshun friendly ping

[lex111]

Anybody here? 😃

[bravo-kernel]

@lex111 I just tried deeplinking against the preview using https://deploy-preview-2162--docusaurus-2.netlify.com/docs/cli/#docusaurus-swizzle and must say that I would prefer to see the anchor text/title, looking only at the text below it makes me (always) scroll up a little to see if things went well.

I also noticed that the Header component does not add anchors which is probably a separate request but very useful for autogenerated pages that ref the H1 anchor.

[bravo-kernel]

This is what i see when using mentioned deeplink:

[yangshun]

Does this preserve functionality for sites without the hideable navbar?

[lex111]

This is what i see when using mentioned deeplink:

It is strange, there shouldn’t be one, header should be hidden when following the link with anchor. I changed something, so try again.

Does this preserve functionality for sites without the hideable navbar?

Ah, yeah, did it. ✔️

[bravo-kernel]

@lex111 thanks for the quick action. The deeplink now opens as expected 💃

[bravo-kernel]

Can you confirm that the H1 element on the docs pages are indeed missing anchors? I understand that this is probably a separate issue but I would like confirmation before I create a ticket.

[lex111]

@bravo-kernel h1 elements do not contain an anchor, and why is it needed? These headers are at the very top of the page, so there is no point in the anchors, right?

[bravo-kernel]

If we use hide_title: false the (markdown) H1 that gets rendered does have anchors.

This is useful/required for e.g. pages that autogenerate documentation like jsdoc. They create references/links to the main class and that link points to the H1 anchor (liike it would also do in e.g. github md view).

I think it would be best if markdown H1 and Heading would produce the same consistent and predictable behavior.

[bravo-kernel]

No big thing btw, just wanted to share the finding, I can work around it for jsdoc

[bravo-kernel]

@lex111 I read more about the H1 anchor and agree with your statement; the Heading component is probably correct here (no anchor needed).

[yangshun]

I tested locally with non-hidable navbar too. Looks good but now the fake anchor gets highlighted when I click from the sidebar. See example:

Self-merge after fixing.

[bravo-kernel]

Thanks 👏