doc: boards: extensions: store board_catalog in Sphinx domain

Load the board catalog only once at build-inited time so that
it's cached and enabled things like boards, vendors, and socs
to eventually become first class Sphinx objects.

Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>

doc/_extensions/zephyr/domain/__init__.py

@@ -578,13 +578,16 @@ class BoardCatalogDirective(SphinxDirective):
         if self.env.app.builder.format == "html":
             self.env.domaindata["zephyr"]["has_board_catalog"][self.env.docname] = True
 
-            # As it is not expected that more than one board-catalog directive is used across
-            # the documentation, and since the generation is only taking a few seconds,  we don't
-            # store the catalog in the domain data. It might change in the future if the generation
-            # becomes more expensive.
-            board_catalog = get_catalog()
+            domain_data = self.env.domaindata["zephyr"]
             renderer = SphinxRenderer([TEMPLATES_DIR])
-            rendered = renderer.render("board-catalog.html", {"catalog": board_catalog})
+            rendered = renderer.render(
+                "board-catalog.html",
+                {
+                    "boards": domain_data["boards"],
+                    "vendors": domain_data["vendors"],
+                    "socs": domain_data["socs"],
+                },
+            )
             return [nodes.raw("", rendered, format="html")]
         else:
             return [nodes.paragraph(text="Board catalog is only available in HTML.")]
@@ -804,6 +807,13 @@ def install_static_assets_as_needed(
         app.add_js_file("js/board-catalog.js")
 
 
+def load_board_catalog_into_domain(app: Sphinx) -> None:
+    board_catalog = get_catalog()
+    app.env.domaindata["zephyr"]["boards"] = board_catalog["boards"]
+    app.env.domaindata["zephyr"]["vendors"] = board_catalog["vendors"]
+    app.env.domaindata["zephyr"]["socs"] = board_catalog["socs"]
+
+
 def setup(app):
     app.add_config_value("zephyr_breathe_insert_related_samples", False, "env")
 
@@ -820,6 +830,8 @@ def setup(app):
         "builder-inited",
         (lambda app: app.config.html_static_path.append(RESOURCES_DIR.as_posix())),
     )
+    app.connect("builder-inited", load_board_catalog_into_domain)
+
     app.connect("html-page-context", install_static_assets_as_needed)
     app.connect("env-updated", compute_sample_categories_hierarchy)
 

doc/_extensions/zephyr/domain/templates/board-card.html

@@ -16,7 +16,7 @@
   data-vendor="{{ board.vendor }}"
   data-socs="{{ board.socs | join(" ") }}"
   tabindex="0">
-  <div class="vendor">{{ catalog.vendors[board.vendor] }}</div>
+  <div class="vendor">{{ vendors[board.vendor] }}</div>
   {% if board.image -%}
   <img alt="A picture of the {{ board.full_name }} board"
     src="../_images/{{ board.image.split('/')[-1] }}" class="picture" />

doc/_extensions/zephyr/domain/templates/board-catalog.html

@@ -38,8 +38,8 @@
         <option value="" disabled selected>Select a vendor</option>
         {# Only show those vendors that have actual boards in the catalog.
            Note: as sorting per vendor name is not feasible in Jinja, the option list is sorted in the JavaScript code later #}
-        {% for vendor in (catalog.boards | items | map(attribute='1.vendor') | unique ) -%}
-        <option value="{{ vendor }}">{{ catalog.vendors[vendor] }}</option>
+        {% for vendor in (boards | items | map(attribute='1.vendor') | unique ) -%}
+        <option value="{{ vendor }}">{{ vendors[vendor] }}</option>
         {% endfor %}
       </select>
     </div>
@@ -82,11 +82,11 @@
 <div id="nb-matches" style="text-align: center"></div>
 
 <div id="catalog">
-  {% for board_name, board in catalog.boards | items | sort(attribute='1.full_name') -%}
+  {% for board_name, board in boards | items | sort(attribute='1.full_name') -%}
   {% include "board-card.html" %}
   {% endfor %}
 </div>
 
 <script>
-  socs_data = {{ catalog.socs | tojson }};
+  socs_data = {{ socs | tojson }};
 </script>