Support and prefer .jinja to _t for static templates

CHANGES

@@ -23,6 +23,11 @@ Deprecated
 ----------
 
 * #11247: Deprecate the legacy ``intersphinx_mapping`` format
+* #11165: Warn when the ``_t`` suffix is used for template files. The formal
+  deprecation process will begin no earlier than 31 December 2024.
+  Templates should change to use the ``.jinja`` filename suffix instead.
+  For more information, see :ref:`theming-static-templates`.
+  Patch by James Addison and Adam Turner
 
 Features added
 --------------
@@ -60,6 +65,10 @@ Features added
   ``= 'xelatex'``.  Patch by Dimitar Dimitrov
 * #11109, #9643: Add :confval:`python_display_short_literal_types` option for
   condensed rendering of ``Literal`` types.
+* #11165: Support the `officially recommended`_ ``.jinja`` suffix for template
+  files. Patch by James Addison
+
+  .. _officially recommended: https://jinja.palletsprojects.com/en/latest/templates/#template-file-extension
 
 Bugs fixed
 ----------

doc/development/theming.rst

@@ -156,13 +156,51 @@ template static files as well as HTML files.  Therefore, Sphinx supports
 so-called "static templates", like this:
 
 If the name of a file in the ``static/`` directory of a theme (or in the user's
-static path, for that matter) ends with ``_t``, it will be processed by the
-template engine.  The ``_t`` will be left from the final file name.  For
-example, the *classic* theme has a file ``static/classic.css_t`` which uses
-templating to put the color options into the stylesheet.  When a documentation
+static path, for that matter) ends with ``.jinja``, it will be processed by the
+template engine.  The ``.jinja`` will be removed from the final file name.  For
+example, the *classic* theme has a file ``static/classic.css.jinja`` which uses
+templating to put the colour options into the stylesheet.  When a documentation
 is built with the classic theme, the output directory will contain a
 ``_static/classic.css`` file where all template tags have been processed.
 
+.. versionchanged:: 6.2
+
+   The preferred suffix for static templates is now ``.jinja``, in line with
+   the Jinja project's `recommended file extension`_.
+
+   The ``_t`` file suffix for static templates is now considered 'legacy', and
+   support will eventually be removed. The standard deprecation process will
+   begin no earlier than 31 December 2024, at which point using ``_t`` suffixes
+   will emit ``RemovedInSphinx__Warning`` warnings.
+
+   If a static template with a ``_t`` suffix is detected, it will be processed
+   by the template engine, with the ``_t`` suffix removed from the final file
+   name.
+
+   To silence the warning for ``_t`` suffixes, the new
+   ``sphinx.deprecation.OldJinjaSuffixWarning`` class has been added for use
+   with Python's standard `warning control`_ mechanisms. This class will be
+   removed no earlier than 31 December 2024, so guard any imports with a
+   try/except block.
+   For example, in a ``setup()`` function:
+
+   .. code:: python
+
+       import warnings
+
+       def setup(app):
+           try:
+               from sphinx.deprecation import OldJinjaSuffixWarning
+           except ImportError:
+               pass  # Only silence the warning if it exists!
+           else:
+               warnings.filterwarnings('ignore', category=OldJinjaSuffixWarning)
+
+           ...
+
+  .. _recommended file extension: https://jinja.palletsprojects.com/en/latest/templates/#template-file-extension
+  .. _warning control: https://docs.python.org/3/library/warnings.html#the-warnings-filter
+
 
 Use custom page metadata in HTML templates
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

doc/latex.rst

@@ -1811,12 +1811,12 @@ Miscellany
 .. hint::
 
    As an experimental feature, Sphinx can use user-defined template file for
-   LaTeX source if you have a file named ``_templates/latex.tex_t`` in your
+   LaTeX source if you have a file named ``_templates/latex.tex.jinja`` in your
    project.
 
-   Additional files ``longtable.tex_t``, ``tabulary.tex_t`` and
-   ``tabular.tex_t`` can be added to ``_templates/`` to configure some aspects
-   of table rendering (such as the caption position).
+   Additional files ``longtable.tex.jinja``, ``tabulary.tex.jinja`` and
+   ``tabular.tex.jinja`` can be added to ``_templates/`` to configure some
+   aspects of table rendering (such as the caption position).
 
    .. versionadded:: 1.6
       currently all template variables are unstable and undocumented.

sphinx/builders/_epub_base.py

@@ -603,7 +603,8 @@ def build_content(self) -> None:
                                             html.escape(self.refnodes[0]['refuri'])))
 
         # write the project file
-        copy_asset_file(path.join(self.template_dir, 'content.opf_t'), self.outdir, metadata)
+        content_t = path.join(self.template_dir, 'content.opf.jinja')
+        copy_asset_file(content_t, self.outdir, metadata)
 
     def new_navpoint(self, node: dict[str, Any], level: int, incr: bool = True) -> NavPoint:
         """Create a new entry in the toc from the node at given level."""
@@ -686,7 +687,7 @@ def build_toc(self) -> None:
         navpoints = self.build_navpoints(refnodes)
         level = max(item['level'] for item in self.refnodes)
         level = min(level, self.config.epub_tocdepth)
-        copy_asset_file(path.join(self.template_dir, 'toc.ncx_t'), self.outdir,
+        copy_asset_file(path.join(self.template_dir, 'toc.ncx.jinja'), self.outdir,
                         self.toc_metadata(level, navpoints))
 
     def build_epub(self) -> None:

sphinx/builders/changes.py

@@ -133,10 +133,10 @@ def hl(no: int, line: str) -> str:
                 f.write(self.templates.render('changes/rstsource.html', ctx))
         themectx = {'theme_' + key: val for (key, val) in
                     self.theme.get_options({}).items()}
-        copy_asset_file(path.join(package_dir, 'themes', 'default', 'static', 'default.css_t'),
-                        self.outdir, context=themectx, renderer=self.templates)
-        copy_asset_file(path.join(package_dir, 'themes', 'basic', 'static', 'basic.css'),
-                        self.outdir)
+        default_t = path.join(package_dir, 'themes', 'default', 'static', 'default.css.jinja')
+        copy_asset_file(default_t, self.outdir, context=themectx, renderer=self.templates)
+        basic = path.join(package_dir, 'themes', 'basic', 'static', 'basic.css')
+        copy_asset_file(basic, self.outdir)
 
     def hl(self, text: str, version: str) -> str:
         text = html.escape(text)

sphinx/builders/epub3.py

@@ -184,7 +184,7 @@ def build_navigation_doc(self) -> None:
             # 'includehidden'
             refnodes = self.refnodes
         navlist = self.build_navlist(refnodes)
-        copy_asset_file(path.join(self.template_dir, 'nav.xhtml_t'), self.outdir,
+        copy_asset_file(path.join(self.template_dir, 'nav.xhtml.jinja'), self.outdir,
                         self.navigation_doc_metadata(navlist))
 
         # Add nav.xhtml to epub file

sphinx/builders/gettext.py

@@ -283,7 +283,7 @@ def finish(self) -> None:
             ensuredir(path.join(self.outdir, path.dirname(textdomain)))
 
             context['messages'] = list(catalog)
-            content = GettextRenderer(outdir=self.outdir).render('message.pot_t', context)
+            content = GettextRenderer(outdir=self.outdir).render('message.pot.jinja', context)
 
             pofn = path.join(self.outdir, textdomain + '.pot')
             if should_write(pofn, content):

sphinx/builders/latex/__init__.py

@@ -402,7 +402,7 @@ def copy_support_files(self) -> None:
         # use pre-1.6.x Makefile for make latexpdf on Windows
         if os.name == 'nt':
             staticdirname = path.join(package_dir, 'texinputs_win')
-            copy_asset_file(path.join(staticdirname, 'Makefile_t'),
+            copy_asset_file(path.join(staticdirname, 'Makefile.jinja'),
                             self.outdir, context=context)
 
     @progress_message(__('copying additional files'))
@@ -441,7 +441,7 @@ def write_message_catalog(self) -> None:
         if self.context['babel'] or self.context['polyglossia']:
             context['addtocaptions'] = r'\addto\captions%s' % self.babel.get_language()
 
-        filename = path.join(package_dir, 'templates', 'latex', 'sphinxmessages.sty_t')
+        filename = path.join(package_dir, 'templates', 'latex', 'sphinxmessages.sty.jinja')
         copy_asset_file(filename, self.outdir, context=context, renderer=LaTeXRenderer())
 
 

sphinx/cmd/quickstart.py

@@ -370,29 +370,29 @@ def write_file(fpath: str, content: str, newline: str | None = None) -> None:
             if 'quiet' not in d:
                 print(__('File %s already exists, skipping.') % fpath)
 
-    conf_path = os.path.join(templatedir, 'conf.py_t') if templatedir else None
+    conf_path = os.path.join(templatedir, 'conf.py.jinja') if templatedir else None
     if not conf_path or not path.isfile(conf_path):
-        conf_path = os.path.join(package_dir, 'templates', 'quickstart', 'conf.py_t')
+        conf_path = os.path.join(package_dir, 'templates', 'quickstart', 'conf.py.jinja')
     with open(conf_path, encoding="utf-8") as f:
         conf_text = f.read()
 
     write_file(path.join(srcdir, 'conf.py'), template.render_string(conf_text, d))
 
     masterfile = path.join(srcdir, d['master'] + d['suffix'])
-    if template._has_custom_template('quickstart/master_doc.rst_t'):
+    if template._has_custom_template('quickstart/master_doc.rst.jinja'):
         msg = ('A custom template `master_doc.rst_t` found. It has been renamed to '
                '`root_doc.rst_t`.  Please rename it on your project too.')
         print(colorize('red', msg))
-        write_file(masterfile, template.render('quickstart/master_doc.rst_t', d))
+        write_file(masterfile, template.render('quickstart/master_doc.rst.jinja', d))
     else:
-        write_file(masterfile, template.render('quickstart/root_doc.rst_t', d))
+        write_file(masterfile, template.render('quickstart/root_doc.rst.jinja', d))
 
     if d.get('make_mode') is True:
-        makefile_template = 'quickstart/Makefile.new_t'
-        batchfile_template = 'quickstart/make.bat.new_t'
+        makefile_template = 'quickstart/Makefile.new.jinja'
+        batchfile_template = 'quickstart/make.bat.new.jinja'
     else:
-        makefile_template = 'quickstart/Makefile_t'
-        batchfile_template = 'quickstart/make.bat_t'
+        makefile_template = 'quickstart/Makefile.jinja'
+        batchfile_template = 'quickstart/make.bat.jinja'
 
     if d['makefile'] is True:
         d['rsrcdir'] = 'source' if d['sep'] else '.'

sphinx/deprecation.py

@@ -62,3 +62,31 @@ def __getattr__(name):
 
     warnings.warn(message + " Check CHANGES for Sphinx API modifications.",
                   warning_class, stacklevel=3)
+
+
+class OldJinjaSuffixWarning(PendingDeprecationWarning):
+    """Warning class for ``_old_jinja_template_suffix_warning``.
+
+    This class exists only so that extensions and themes can silence the legacy
+    filename warning via Python's `warning control`_ mechanisms. See
+    :ref:`theming-static-templates` for an example.
+
+    This warning class will be removed, and the warning class changed to the
+    appropriate RemovedInSphinx_0Warning no earlier than 31 December 2024, at
+    which point the standard deprecation process for ``_t`` template suffixes
+    will start.
+
+    .. _warning control: https://docs.python.org/3/library/warnings.html#the-warnings-filter
+    """
+
+
+def _old_jinja_template_suffix_warning(filename: str) -> None:
+    if filename.endswith('_t'):
+        warnings.warn(
+            f"{filename!r}: the '_t' suffix for Jinja templates is deprecated. "
+            "If the file is a template, use the suffix '.jinja' instead. "
+            'For more information, see '
+            'https://www.sphinx-doc.org/en/master/development/theming.html#static-templates',
+            OldJinjaSuffixWarning,
+            stacklevel=3,
+        )

sphinx/ext/apidoc.py

@@ -102,7 +102,7 @@ def create_module_file(package: str, basename: str, opts: Any,
         'qualname': qualname,
         'automodule_options': options,
     }
-    text = ReSTRenderer([user_template_dir, template_dir]).render('module.rst_t', context)
+    text = ReSTRenderer([user_template_dir, template_dir]).render('module.rst.jinja', context)
     write_file(qualname, text, opts)
 
 
@@ -138,7 +138,8 @@ def create_package_file(root: str, master_package: str, subroot: str, py_files:
         'show_headings': not opts.noheadings,
         'maxdepth': opts.maxdepth,
     }
-    text = ReSTRenderer([user_template_dir, template_dir]).render('package.rst_t', context)
+    engine = ReSTRenderer([user_template_dir, template_dir])
+    text = engine.render('package.rst.jinja', context)
     write_file(pkgname, text, opts)
 
     if submodules and opts.separatemodules:
@@ -163,7 +164,7 @@ def create_modules_toc_file(modules: list[str], opts: Any, name: str = 'modules'
         'maxdepth': opts.maxdepth,
         'docnames': modules,
     }
-    text = ReSTRenderer([user_template_dir, template_dir]).render('toc.rst_t', context)
+    text = ReSTRenderer([user_template_dir, template_dir]).render('toc.rst.jinja', context)
     write_file(name, text, opts)
 
 

sphinx/ext/imgmath.py

@@ -19,6 +19,7 @@
 from sphinx.application import Sphinx
 from sphinx.builders import Builder
 from sphinx.config import Config
+from sphinx.deprecation import _old_jinja_template_suffix_warning
 from sphinx.errors import SphinxError
 from sphinx.locale import _, __
 from sphinx.util import logging, sha1
@@ -95,16 +96,20 @@ def generate_latex_macro(image_format: str,
     }
 
     if config.imgmath_use_preview:
-        template_name = 'preview.tex_t'
+        template_name = 'preview.tex'
     else:
-        template_name = 'template.tex_t'
+        template_name = 'template.tex'
 
     for template_dir in config.templates_path:
-        template = path.join(confdir, template_dir, template_name)
-        if path.exists(template):
-            return LaTeXRenderer().render(template, variables)
-
-    return LaTeXRenderer(templates_path).render(template_name, variables)
+        # TODO: deprecate '_t' template suffix support after 2024-12-31
+        for template_suffix in ('_t', '.jinja'):
+            template = path.join(confdir, template_dir, template_name + template_suffix)
+            if path.exists(template):
+                _old_jinja_template_suffix_warning(template)
+                return LaTeXRenderer().render(template, variables)
+
+    # Default: fallback to a pathless in-library jinja template
+    return LaTeXRenderer(templates_path).render(f"{template_name}.jinja", variables)
 
 
 def ensure_tempdir(builder: Builder) -> str:

sphinx/util/fileutil.py

@@ -8,13 +8,27 @@
 
 from docutils.utils import relative_path
 
+from sphinx.deprecation import _old_jinja_template_suffix_warning
 from sphinx.util.osutil import copyfile, ensuredir
 from sphinx.util.typing import PathMatcher
 
 if TYPE_CHECKING:
     from sphinx.util.template import BaseRenderer
 
 
+def _template_basename(filename: str) -> str | None:
+    """Given an input filename:
+    If the input looks like a template, then return the filename output should
+    be written to.  Otherwise, return no result (None)."""
+    # TODO: deprecate '_t' template suffix support after 2024-12-31
+    if filename.lower().endswith('_t'):
+        _old_jinja_template_suffix_warning(filename)
+        return filename[:-2]
+    elif filename.lower().endswith(".jinja"):
+        return filename[:-6]
+    return None
+
+
 def copy_asset_file(source: str, destination: str,
                     context: dict | None = None,
                     renderer: BaseRenderer | None = None) -> None:
@@ -35,14 +49,13 @@ def copy_asset_file(source: str, destination: str,
         # Use source filename if destination points a directory
         destination = os.path.join(destination, os.path.basename(source))
 
-    if source.lower().endswith('_t') and context is not None:
+    if _template_basename(source) and context is not None:
         if renderer is None:
             from sphinx.util.template import SphinxRenderer
             renderer = SphinxRenderer()
 
         with open(source, encoding='utf-8') as fsrc:
-            if destination.lower().endswith('_t'):
-                destination = destination[:-2]
+            destination = _template_basename(destination) or destination
             with open(destination, 'w', encoding='utf-8') as fdst:
                 fdst.write(renderer.render_string(fsrc.read(), context))
     else: