Localization of The Gazebo Documentation

[hwhsu1231]

Announcement

Hello Gazebo Community,

I am the author of the @localizethedocs organization. And I’m glad to announce that the 🎉 gazebosim-docs-l10n 🎉 project is published now:

• 🚀 Preview: gazebosim-docs-l10n
• 🌐 Crowdin: gazebosim-docs-l10n
• 🐙 GitHub: gazebosim-docs-l10n

The goal of this project is to translate The Gazebo Documentation into multiple languages. Translations are contributed via the Crowdin platform, automatically synchronized with the GitHub repository, and can be previewed on GitHub Pages.

How to Contribute Translations?

To contribute the translations, just follow the following steps:

1. Create an account on Crowdin Enterprise if you don't have one.
2. Log in and go the gazebosim-docs-l10n project.
3. Choose the language you would like to contribute.

If translators want to translate a language that is not yet supported, they just need to open a new issue to request the new language. Once the requested language is added, they can begin translating.

How to Keep Content Up-to-date?

An FAQ that is sure to come up in the community is: How to keep translations up-to-date?

First and foremost, in my opinion, the focus should be on how to keep the "Translatable Content (msgid)" up-to-date, rather than the "Translations (msgstr)". I will focus on the most critical part of the whole infrastructure here.

In short, the ci-sphinx-update-pot.yml workflow will be executed weekly to check the upstream project for any required updates to the document content, which in turn triggers the update of the .pot files. If an update is needed, a Pull Request (PR) is automatically created to merge into the l10n branch. For example:

• 🌐 pot(rotary): update .pot from Sphinx localizethedocs/gazebosim-docs-l10n#2
• 🌐 pot(garden): update .pot from Sphinx localizethedocs/gazebosim-docs-l10n#3
• 🌐 pot(ionic): update .pot from Sphinx localizethedocs/gazebosim-docs-l10n#4

Once those PRs are merged, the ci-gettext-update-po.yml workflow will be triggered to merge the updated content from the .pot files into the .po files for each language. This is essentially how @localizethedocs keeps the "Translatable Content" up-to-date.

Therefore, the core responsibility of the code maintainers, besides ensuring the stable operation of the scripts and workflows, is to regularly check whether there are any pending PRs that need to be merged.

How to Reuse Translations?

If the upstream project or anyone wants to reuse the translated .po files prepared by the gazebosim-docs-l10n project, they can clone the .po files from the po/${VERSION} branch by using the following command:

git clone --depth=1 --branch=po/${VERSION} https://github.com/localizethedocs/gazebosim-docs-l10n.git docs/locale

Those po/${VERSION} branches are created to facilitate reusage by the upstream project. For instance, the zh_TW documentation for the rotary version can be generated using the commands below:

BRANCH=master
VERSION=rotary
LANGUAGE=zh_TW
BUILDER=dirhtml
VENVDIR=$(pwd)/.conda

# Prepare the repository and environment
git clone --branch=${BRANCH} --depth=1 https://github.com/gazebosim/docs.git gzsim-docs
cd gzsim-docs
conda create --prefix ${VENVDIR} --yes
conda activate ${VENVDIR}
conda install python=3.12 -c conda-forge -c nodefaults --yes
export PYTHONNOUSERSITE=1
python -m ensurepip --default-pip
python -m pip install -r requirements.txt

# Generate source directory
cat << 'EOF' > generate_sources.py
import sys
from pathlib import Path
import yaml
from build_multiversion import generate_sources

def main():
    src_dir = Path(".")  # points to your project directory
    tmp_dir = src_dir / ".tmp"
    tmp_dir.mkdir(exist_ok=True)

    # read index.yaml
    with open(src_dir / "index.yaml") as f:
        gz_nav_yaml = yaml.safe_load(f)

    # extract command line argument as release
    if len(sys.argv) < 2:
        print("Usage: python generate_sources.py <release>")
        sys.exit(1)

    release = sys.argv[1]
    generate_sources(gz_nav_yaml, src_dir, tmp_dir, release)

if __name__ == "__main__":
    main()
EOF
python generate_sources.py $VERSION

# Clone the .po files to the 'locale' directory
git clone --branch=po/${VERSION} --depth=1 https://github.com/localizethedocs/gazebosim-docs-l10n.git .tmp/$VERSION/locale

# Build the documentation
pushd .tmp/$VERSION
sphinx-build \
    -b ${BUILDER} \
    -D language=${LANGUAGE} \
    -D locale_dirs=locale \
    -D gettext_compact=0 \
    -D gettext_additional_targets=index,literal-block,raw \
    -D gz_release=$VERSION \
    -D gz_root_index_file=../../index.yaml \
    . \
    ./_build/${LANGUAGE}
popd

# Preview the documentation
firefox .tmp/$VERSION/_build/${LANGUAGE}/index.html