docs: add custom html_template_vars extension

docs/_templates/sidebar/brand.html

@@ -3,7 +3,7 @@
     <img class="sidebar-logo" src="{{ pathto('_static/' + logo, 1) }}" alt="{{ project }}"/>
   </div>
   <p class="sidebar-brand-text">{{ project }}</p>
-  <p class="sidebar-brand-oneliner">A command-line utility that extracts streams from various services and pipes them into a video player of choice.</p>
+  <p class="sidebar-brand-oneliner">{{ oneliner }}</p>
 </a>
 <div class="sidebar-versions centered" role="note" aria-label="versions">
   <pre class="sidebar-versions-current">{{ release }}</pre>

docs/conf.py

@@ -20,6 +20,7 @@ extensions = [
     'sphinx.ext.autodoc',
     'sphinx.ext.autosectionlabel',
     'sphinx.ext.intersphinx',
+    'ext_html_template_vars',
     'ext_argparse',
     'ext_github',
     'ext_plugins',
@@ -129,6 +130,13 @@ html_theme_options = {
 # Add any paths that contain custom themes here, relative to this directory.
 #html_theme_path = []
 
+# HTML template variables via the custom ext_html_template_vars extension
+html_template_vars = {
+    "oneliner": (
+        "A command-line utility that extracts streams from various services and pipes them into a video player of choice."
+    ),
+}
+
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
 #html_title = None

docs/ext_html_template_vars.py

@@ -0,0 +1,23 @@
+from typing import Any, Dict
+
+from sphinx.addnodes import document
+from sphinx.application import Sphinx
+
+
+_CONFIG_VAR = "html_template_vars"
+
+
+def update_context(
+    app: Sphinx,
+    pagename: str,
+    templatename: str,
+    context: Dict[str, Any],
+    doctree: document,
+) -> None:
+    for k, v in getattr(app.config, _CONFIG_VAR).items():
+        context[k] = v
+
+
+def setup(app: Sphinx) -> None:
+    app.add_config_value(_CONFIG_VAR, {}, "")
+    app.connect("html-page-context", update_context)