dev/release/docs.md

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# How to publish docs

## Overview

We publish our official docs to the following locations:

* https://arrow.apache.org/js/current/ : For the current release
* https://arrow.apache.org/js/${VERSION} : For the specified version such as `21.0.0`
* https://arrow.apache.org/js/main/ : For the `main` branch

We also publish docs for fork repositories for preview. It uses the
following locations:

* https://${GITHUB_ID}.github.io/arrow-js/ : List all available docs
* https://${GITHUB_ID}.github.io/arrow-js/${BRANCH}/ : For the `${BRANCH}` branch

All of them are automated. This documentation describes how it works.

### apache/arrow-js

apache/arrow-js uses the ASF provided Apache to host generated
documentation. In general, the `asf-site` branch is used for it. See
the `publish.whoami` configuration in the top-level `.asf.yaml`.

Note that we don't need to touch the `asf-site` branch manually. It's
completely maintained automatically. If the `asf-site` branch doesn't
exist, it's created automatically.

If we update the `asf-site` branch, the `asf-site` branch contents
will be published to https://arrow.apache.org/js/ automatically.

https://arrow.apache.org/js/ is always redirected to
https://arrow.apache.org/js/current/ that provides the current release
documentation. It's implemented by `.htaccess`. `.htaccess` is
generated by `ci/scripts/update_docs.sh`.

The `asf-site` branch is updated when:

* We push a release tag
* We push a commit to the `main` branch (We merge a PR to the `main` branch)

Note that the `asf-site` branch isn't updated when we push an RC
tag. We just build documentation and upload to a GitHub Release when
we push an RC tag. We add the built documentation to the `asf-site`
branch when we push a release tag. In this case, `current/` and
`${VERSION}/` directories in the `asf-site` branch are updated.

We build documentation and add the built documentation to the
`asf-site` when we push a commit to the `main` branch. In this case,
`main/` directory in the `asf-site` branch is updated.

See also `ci/scripts/update_docs.sh`.

### Fork repositories

Fork repositories use GitHub Pages to host generated
documentation. The `gh-pages` branch is used for it.

Note that we don't need to touch the `gh-pages` branch manually. It's
completely maintained automatically. If the `gh-pages` branch doesn't
exist, it's created automatically. If your fork repository's size
becomes bigger by the `gh-pages` branch, you can delete the `gh-pages`
branch. Because it has only temporary data and can be generated
automatically.

You need to enable GitHub Pages on your fork repository. See
[DEVELOP.md](../../DEVELOP.md#how-to-preview-documentation-on-your-fork-repository) how to enable GitHub Pages on your fork repository.

If we update the `gh-pages` branch, the `gh-page` branch contents will
be published to https://${GITHUB_ID}.github.io/arrow-js/
automatically.

https://${GITHUB_ID}.github.io/arrow-js/ shows all available
previews. https://${GITHUB_ID}.github.io/arrow-js/${BRANCH} has a
preview of the `${BRANCH}` branch. If the `${BRANCH}` branch is
deleted, the `${BRANCH}` directory is also deleted from the `gh-pages`
branch when you push a commit to your fork repository.

The `gh-pages` branch is updated when you push a commit to your fork
repository. Our workflow generates a preview for the pushed branch and
deletes previews of nonexistent branches.

See also `ci/scripts/update_docs.sh`.