Sourcing BibTeX files from GitHub

For documentation that references published documents, it’s useful formally cite references in additional to the typical practice of linking directly to other webpages. In the Sphinx documentation system, a good workflow is to code bibliographic references through standard BibTeX files and then reference items in those BibTeX files with the sphinxcontrib-bibtex extension. At Rubin Observatory, we maintain a centralized set of BibTeX files in the lsst/lsst-texmf repository. Documenteer provides a Sphinx extension, documenteer.ext.githubbibcache, that downloads BibTeX files from one or more GitHub repositories, caches them, and automatically configures sphinxcontrib-bibtex to use those BibTeX files. This page explains how to set up documenteer.ext.githubbibcache in your Sphinx documentation project and use it in conjunction with the sphinxcontrib-bibtex extension.

Tip

If you’re using one of the Documenteer configuration presets for Rubin Observatory documents, your Sphinx project is already configured to use lsst/lsst-texmf bibliography files. All you need to do is use the sphinxcontrib-bibtex extension’s citation roles and ensure that a bibliography directive is present in your documentation project.

Extension set up

The extension from Documenteer needs to be loaded _before_ the sphinxcontrib-bibtex extension because it adds configurations that are later used by sphinxcontrib-bibtex. In your project’s conf.py file, set up the extensions like this:

conf.py

extensions = [
    "documenteer.ext.githubbibcache",
    "sphinxcontrib.bibtex",
]

Note

If you’re using BibTeX files from lsst/lsst-texmf, you’ll need to set also add an extension that supports Rubin Observatory’s custom @DocuShare BibTeX entry type through BibTeX style extension for Rubin Observatory. This configuration is then:

conf.py

extensions = [
    "documenteer.ext.bibtex",
    "documenteer.ext.githubbibcache",
    "sphinxcontrib.bibtex",
]

bibtex_default_style = "lsst_aa"

The style configuration specifies the style provided by documenteer.ext.bibtex.

Specify the GitHub repositories and their BibTeX files

In conf.py, you’ll need to specify the GitHub repositories and their BibTeX files that you want to use. The documenteer_bibfile_github_repos variable is a list of dictionaries, where each dictionary has the following keys:

• repo: the GitHub repository name, e.g., lsst/lsst-texmf.

• ref: the Git reference (branch, tag, or commit hash) to use, e.g., main.

• bibfiles: a list of paths to BibTeX files to download from the repository, e.g., ['texmf/bibtex/bib/refs.bib', 'texmf/bibtex/bib/lsst.bib'].

This is a sample configuration used in by Rubin Observatory’s technote configuration:

conf.py

documenteer_bibfile_cache_dir = ".technote/bibfiles"
documenteer_bibfile_github_repos = [
    {
        "repo": "lsst/lsst-texmf",
        "ref": "main",
        "bibfiles": [
            "texmf/bibtex/bib/lsst.bib",
            "texmf/bibtex/bib/lsst-dm.bib",
            "texmf/bibtex/bib/refs_ads.bib",
            "texmf/bibtex/bib/refs.bib",
            "texmf/bibtex/bib/books.bib",
        ],
    }
]
# Set up bibtex_bibfiles
bibtex_bibfiles = []

# Automatically load local bibfiles in the root directory.
for p in Path.cwd().glob("*.bib"):
    bibtex_bibfiles.append(str(p))

bibtex_default_style = "lsst_aa"
bibtex_reference_style = "author_year"

Create a bibliography and make citations

The extension, documenteer.ext.githubbibcache, configures sphinxcontrib-bibtex to use the specified BibTeX files from GitHub. Now you can use sphinxcontrib-bibtex as normal in your documentation project.

First, ensure there’s a bibliography directive in your documentation project:

index.rst

References
==========

.. bibliography::

Then, you can use the citation roles provided by sphinxcontrib-bibtex.

Regular citations are made with the cite role, and textual citations are made with the cite:t role:

index.rst

Rubin Observatory is a large astronomical survey telescope that will be
used to study the Universe :cite:`2019ApJ...873..111I`.

The Science Book :cite:t:`2009arXiv0912.0201L` describes the science goals
of Rubin Observatory.

Clearing the BibTeX cache

By default, the extension caches the BibTeX files in a directory called _build/bibfile-cache relative to your project’s conf.py file. You can also customize this directory by setting the documenteer_bibfile_cache_dir variable in conf.py. For example, Documenteer’s technote configuration sets this variable to .technote/bibfiles. To get new copies of the bibtex files from GitHub, you can delete the cache directory and rebuild your documentation project.