Add support for internationalization to the guide

.gitignore

@@ -9,3 +9,5 @@ __pycache__
 *.idea*
 # Grammar / syntax checkers
 styles/
+# Exclude translation .mo files
+locales/*/LC_MESSAGES/*.mo

.pre-commit-config.yaml

@@ -33,7 +33,7 @@ repos:
         - tomli
       exclude: >
         (?x)^(
-            .*vale-styles.*
+            (.*vale-styles.*)|(.*\.po)
         )$
 
   - repo: https://github.com/errata-ai/vale

noxfile.py

@@ -5,80 +5,213 @@
 
 nox.options.reuse_existing_virtualenvs = True
 
-OUTPUT_DIR = "_build"
-docs_dir = os.path.join("_build", "html")
-build_command = ["-b", "html", ".", docs_dir]
+## Sphinx related options
+
+# Sphinx output and source directories
+BUILD_DIR = '_build'
+OUTPUT_DIR = pathlib.Path(BUILD_DIR, "html")
+SOURCE_DIR = pathlib.Path(".")
+
+# Location of the translation templates
+TRANSLATION_TEMPLATE_DIR = pathlib.Path(BUILD_DIR, "gettext")
+TRANSLATION_LOCALES_DIR = pathlib.Path("locales")
+
+# Sphinx build commands
+SPHINX_BUILD = "sphinx-build"
+SPHINX_AUTO_BUILD = "sphinx-autobuild"
+
+# Sphinx parameters used to build the guide
+BUILD_PARAMETERS = ["-b", "html"]
+
+# Sphinx parameters used to test the build of the guide
+TEST_PARAMETERS = ['-W', '--keep-going', '-E', '-a']
+
+# Sphinx parameters to generate translation templates
+TRANSLATION_TEMPLATE_PARAMETERS = ["-b", "gettext"]
+
+# Sphinx-autobuild ignore and include parameters
+AUTOBUILD_IGNORE = [
+    "_build",
+    ".nox",
+    "build_assets",
+    "tmp",
+]
+AUTOBUILD_INCLUDE = [
+    pathlib.Path("_static", "pyos.css")
+]
+
+## Localization options (translations)
+
+# List of languages for which locales will be generated in (/locales/<lang>)
+LANGUAGES = ["es"]
+
+# List of languages that should be built when releasing the guide (docs or docs-test sessions)
+RELEASE_LANGUAGES = []
+
 
 @nox.session
 def docs(session):
+    """Build the packaging guide."""
     session.install("-e", ".")
-    cmd = ["sphinx-build"]
-    cmd.extend(build_command + session.posargs)
-    session.run(*cmd)
+    session.run(SPHINX_BUILD, *BUILD_PARAMETERS, SOURCE_DIR, OUTPUT_DIR, *session.posargs)
+    # When building the guide, also build the translations in RELEASE_LANGUAGES
+    session.notify("build-translations", ['release-build'])
+
 
 @nox.session(name="docs-test")
 def docs_test(session):
     """
-    Same as `docs`, but rebuild everything and fail on warnings for testing
+    Build the packaging guide with more restricted parameters.
+
+    Note: this is the session used in CI/CD to release the guide.
     """
     session.install("-e", ".")
-    cmd = ["sphinx-build"]
-    cmd.extend(['-W', '--keep-going', '-E', '-a'])
-    cmd.extend(build_command + session.posargs)
-    session.run(*cmd)
+    session.run(SPHINX_BUILD, *BUILD_PARAMETERS, *TEST_PARAMETERS, SOURCE_DIR, OUTPUT_DIR, *session.posargs)
+    # When building the guide with additional parameters, also build the translations in RELEASE_LANGUAGES
+    # with those same parameters.
+    session.notify("build-translations", ['release-build', *TEST_PARAMETERS])
 
 
 @nox.session(name="docs-live")
 def docs_live(session):
-    session.install("-e", ".")
+    """
+    Build and launch a local copy of the guide.
 
-    AUTOBUILD_IGNORE = [
-        "_build",
-        "build_assets",
-        "tmp",
-    ]
+    This session will use sphinx-autobuild to build the guide and launch a local server so you can
+    browse it locally. It will automatically rebuild the guide when changes are detected in the source.
 
-    # Explicitly include custom CSS in each build since
-    # sphinx doesn't think _static files should change since,
-    # well, they're static.
-    # Include these as the final `filenames` argument
+    It can be used with the language parameter to build a specific translation, for example:
 
-    AUTOBUILD_INCLUDE = [
-        os.path.join("_static", "pyos.css")
-    ]
+        nox -s docs-live -- -D language=es
 
-    # ----------------
-    # Assemble command
-    cmd = ["sphinx-autobuild"]
+    Note: The docs-live-lang session below is provided as a convenience session for beginner contributors
+    so they don't need to remember the specific sphinx-build parameters to build a different language.
+    """
+    session.install("-e", ".")
+    cmd = [SPHINX_AUTO_BUILD, *BUILD_PARAMETERS, SOURCE_DIR, OUTPUT_DIR, *session.posargs]
     for folder in AUTOBUILD_IGNORE:
         cmd.extend(["--ignore", f"*/{folder}/*"])
+    # This part was commented in the previous version of the nox file, keeping the same here
+    # for folder in AUTOBUILD_INCLUDE:
+    #     cmd.extend(["--watch", folder])
+    session.run(*cmd)
 
-    #cmd.extend(build_command)
-    cmd.extend(build_command + session.posargs)
-
-    # Use positional arguments if we have them
-    # if len(session.posargs) > 0:
-    #     cmd.extend(session.posargs)
-    # # Otherwise use default output and include directory
-    # else:
-    #     cmd.extend(AUTOBUILD_INCLUDE)
 
-    session.run(*cmd)
+@nox.session(name="docs-live-lang")
+def docs_live_lang(session):
+    """
+    A convenience session for beginner contributors to use the docs-live session with
+    a specific language.
 
+    It expects the language code to be passed as the first positional argument, so it needs
+    to be called with from the command line with the following syntax:
 
+        nox -s docs-live-lang -- LANG
 
-@nox.session(name="docs-clean")
-def clean_dir(dir_path=docs_dir):
+    where LANG is one of the available languages defined in LANGUAGES.
+    For example, for Spanish: nox -s docs-live-lang -- es
     """
-    Clean out the docs directory used in the
-    live build.
-    """
-    dir_path = pathlib.Path(dir_path)
-    dir_contents = dir_path.glob('*')
+    if not session.posargs:
+        session.error(
+            "Please provide a language using:\n\n      "
+            "nox -s docs-live-lang -- LANG\n\n     "
+            f" where LANG is one of: {LANGUAGES}"
+        )
+    lang = session.posargs[0]
+    if lang in LANGUAGES:
+        session.posargs.pop(0)
+        session.notify("docs-live", ('-D', f"language={lang}", *session.posargs))
+    else:
+        session.error(
+            f"[{lang}] locale is not available. Try using:\n\n      "
+            "nox -s docs-live-lang -- LANG\n\n      "
+            f"where LANG is one of: {LANGUAGES}"
+        )
+
 
+@nox.session(name="docs-clean")
+def clean_dir(session):
+    """Clean out the docs directory used in the live build."""
+    session.warn(f"Cleaning out {OUTPUT_DIR}")
+    dir_contents = OUTPUT_DIR.glob('*')
     for content in dir_contents:
-        print(content)
+        session.log(f'removing {content}')
         if content.is_dir():
             shutil.rmtree(content)
         else:
             os.remove(content)
+
+
+@nox.session(name="update-translations")
+def update_translations(session):
+    """
+    Update the translation files (./locales/*/.po) for all languages translations.
+
+    Note: this step is important because it makes sure that the translation files are
+    up to date with the latest changes in the guide.
+    """
+    session.install("-e", ".")
+    session.install("sphinx-intl")
+    session.log("Updating templates (.pot)")
+    session.run(SPHINX_BUILD, *TRANSLATION_TEMPLATE_PARAMETERS, SOURCE_DIR, TRANSLATION_TEMPLATE_DIR, *session.posargs)
+    for lang in LANGUAGES:
+        session.log(f"Updating .po files for [{lang}] translation")
+        session.run("sphinx-intl", "update", "-p", TRANSLATION_TEMPLATE_DIR, "-l", lang)
+
+
+@nox.session(name="build-languages")
+def build_languages(session):
+    """
+    Build the translations of the guide for the specified language.
+
+    Note: This sessions expects a list of languages to build in the first position of the session arguments.
+    It does not need to be called directly, it is started by build_translations session.
+    """
+    if not session.posargs:
+        session.error("Please provide the list of languages to build the translation for")
+    languages_to_build = session.posargs.pop(0)
+
+    session.install("-e", ".")
+    for lang in languages_to_build:
+        if lang not in LANGUAGES:
+            session.warn(f"Language [{lang}] is not available for translation")
+            continue
+        session.log(f"Building [{lang}] guide")
+        session.run(SPHINX_BUILD, *BUILD_PARAMETERS, "-D", f"language={lang}", ".", OUTPUT_DIR / lang, *session.posargs)
+
+
+@nox.session(name="build-translations")
+def build_translations(session):
+    """
+    Build translations of the guide.
+
+    Note: this session can be called directly to build all available translations (defined in LANGUAGES).
+    It is also called by the docs and docs-test sessions with 'release-build' as the first positional
+    argument, to build only the translations defined in RELEASE_LANGUAGES.
+    """
+    release_build = False
+    if session.posargs and session.posargs[0] == 'release-build':
+        session.posargs.pop(0)
+        release_build = True
+    # if running from the docs or docs-test sessions, build only release languages
+    BUILD_LANGUAGES = RELEASE_LANGUAGES if release_build else LANGUAGES
+    # only build languages that have a locale folder
+    BUILD_LANGUAGES = [lang for lang in BUILD_LANGUAGES if (TRANSLATION_LOCALES_DIR / lang).exists()]
+    session.log(f"Declared languages: {LANGUAGES}")
+    session.log(f"Release languages: {RELEASE_LANGUAGES}")
+    session.log(f"Building languages{' for release' if release_build else ''}: {BUILD_LANGUAGES}")
+    if not BUILD_LANGUAGES:
+        session.warn("No translations to build")
+    else:
+        session.notify("build-languages", [BUILD_LANGUAGES, *session.posargs])
+
+
+@nox.session(name="build-translations-test")
+def build_translations_test(session):
+    """
+    Build all translations of the guide with testing parameters.
+
+    This is a convenience session to test the build of all translations with the testing parameters
+    in the same way docs-test does for the English version.
+    """
+    session.notify("build-translations", [*TEST_PARAMETERS])

pyproject.toml

@@ -26,8 +26,12 @@ dependencies = [
 
 [project.optional-dependencies]
 dev = [
-    # for checking style rules
-    "vale"
+    # for general build workflows
+    "nox",
+    # for prose linting
+    "vale",
+    # for managing translation files
+    "sphinx-intl",
 ]
 
 [tool.hatch.build.targets.wheel]