make cards an extension (#268)

.readthedocs.yaml

@@ -1,6 +1,6 @@
 version: 2
 build:
-  os: ubuntu-22.04
+  os: ubuntu-lts-latest
   tools:
     python: "mambaforge-latest"
   jobs:
@@ -24,6 +24,5 @@ python:
   install:
     - method: pip
       extra_requirements:
-        - all
         - docs
       path: .

docs/conf.py

@@ -35,6 +35,7 @@
     "sphinx.ext.napoleon",
     "sphinx.ext.todo",
     "sphinx.ext.viewcode",
+    "sunpy_sphinx_theme.cards",
 ]
 exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
 source_suffix = ".rst"

src/sunpy_sphinx_theme/__init__.py

@@ -10,8 +10,6 @@
 from pydata_sphinx_theme import utils
 from sphinx.application import Sphinx
 
-from .cards import Card, _Card, depart_card_node, visit_card_node
-
 __all__ = ["get_html_theme_path", "ON_RTD", "PNG_ICON", "SVG_ICON"]
 
 
@@ -141,12 +139,8 @@ def setup(app: Sphinx):
     theme_dir = get_html_theme_path()
     app.add_html_theme("sunpy", theme_dir)
     app.add_css_file("sunpy_style.css", priority=600)
-    app.add_css_file("sunpy_cards.css", priority=600)
-    app.add_directive("custom-card", Card)
-    app.add_node(_Card, html=(visit_card_node, depart_card_node))
     app.connect("builder-inited", update_config)
     app.connect("html-page-context", update_html_context)
-
     # Conditionally include goat counter js
     # We can't do this in update_config as that causes the scripts to be duplicated.
     # Also in here none of the theme defaults have be applied by `update_config`

src/sunpy_sphinx_theme/cards.py

@@ -1,9 +1,10 @@
 """
-This provides the card extension from the website into the theme.
+This provides a card extension for the website.
 """
 
 from docutils import nodes
 from docutils.parsers.rst import Directive, directives
+from sphinx.application import Sphinx
 
 __all__ = ["Card", "_Card", "visit_card_node", "depart_card_node"]
 
@@ -97,3 +98,13 @@ def run(self):
         )
         self.state.nested_parse(self.content, 0, out)
         return [out]
+
+
+def setup(app: Sphinx):
+    app.add_css_file("sunpy_cards.css", priority=600)
+    app.add_directive("custom-card", Card)
+    app.add_node(_Card, html=(visit_card_node, depart_card_node))
+    return {
+        "parallel_read_safe": True,
+        "parallel_write_safe": True,
+    }