feat(theme): support multi-level sidebar

[yizhi996]

#737, fixes #926

Preview:

[brc-dd]

Hi! Did you accidently close this PR?

[yizhi996]

Hi! Did you accidently close this PR?

Hello, I found a css wrong and temporarily closed this PR.

[brc-dd]

Ah okay! Kia will review this once he gets some time. By the way, you can also convert a PR to draft while you're working on it.

[yizhi996]

Ah okay! Kia will review this once he gets some time. By the way, you can also convert a PR to draft while you're working on it.

Thanks, I learned.

[YangYongAn]

期待该 pr 早日合并

[SebasG22]

Looking forward to having this merged!

[cy920820]

Early release pls ~~

[brc-dd]

@yizhi996 Hey I did some updates. Can you check if current code works fine?

[titouanmathis]

I think the getFlatSideBarLinks function in theme-defaults/supports/sidebar.ts should be recursive, too. It currently only goes one level deep, which seems to break the prev and next footer links resolution when I last tested it.

I think that the following function could work recursively (demo):

function getFlatSideBarLinks(sidebar) {
  return sidebar
    .map((item) =>
      Array.isArray(item.items)
        ? [item, ...getFlatSideBarLinks(item.items)]
        : [item]
    )
    .flat();
}

I tested it on this branch, and it seems to work (although TypeScript is not happy):

Before	After

[brc-dd]

Ah, yes thanks @titouanmathis. This actually slipped my mind. Will fix this tomorrow. I'm marking the PR as draft for now.

[yizhi996]

@brc-dd Thanks for the updates to the PR! now it works with link be empty

[yizhi996]

@brc-dd @titouanmathis I have fixed prev and next footer links problem, please check it works fine, thanks.