Add missing docs and tests for API endpoint

Author: thibaudcolas

docs/recipes/api-rendering.md

@@ -0,0 +1,25 @@
+# API rendering
+
+For additional flexibility, django-pattern-library supports rendering patterns via an API endpoint.
+This can be useful when implementing a custom UI while still using the pattern library’s Django rendering features.
+
+The API endpoint is available at `api/v1/render-pattern`. It accepts POST requests with a JSON payload containing the following fields:
+
+- `template_name` – the path of the template to render
+- `config` – the configuration for the template, with the same data structure as the configuration files (`context` and `tags`).
+
+Here is an example, with curl:
+
+```bash
+echo '{"template_name": "patterns/molecules/button/button.html", "config": {"context": {"target_page": {"title": "API"}}, "tags": {"pageurl":{"target_page":{"raw": "/hello-api"}}}}}' | curl -d @- http://localhost:8000/api/v1/render-pattern
+```
+
+The response will be the pattern’s rendered HTML:
+
+```html
+<a href="/hello-api" class="button">
+    API
+</a>
+```
+
+Note compared to iframe rendering, this API always renders the pattern’s HTML standalone, never within a base template.

mkdocs.yml

@@ -50,6 +50,7 @@ nav:
     - 'Inclusion tags': 'recipes/inclusion-tags.md'
     - 'Looping for tags': 'recipes/looping-for-tags.md'
     - 'Pagination': 'recipes/pagination.md'
+    - 'API rendering': 'recipes/api-rendering.md'
   - 'Reference':
     - 'API and settings': 'reference/api.md'
     - 'Concepts': 'reference/concepts.md'

pattern_library/monkey_utils.py

@@ -30,8 +30,7 @@ def node_render(context):
                 tag_overridden = False
                 result = ""
 
-                # Load pattern's config
-                current_template_name = parser.origin.template_name
+                # Get overriden tag config.
                 tag_overrides = context.get("__pattern_library_tag_overrides", {})
 
                 # Extract values for lookup from the token
@@ -87,7 +86,7 @@ def node_render(context):
                     logger.warning(
                         'No default or stub data defined for the "%s" tag in the "%s" template',
                         tag_name,
-                        current_template_name,
+                        parser.origin.template_name,
                     )
 
             return original_node_render(context)

tests/tests/test_views.py

@@ -116,3 +116,32 @@ def test_fragment_extended_from_variable(self):
             ),
             "base content - extended content",
         )
+
+
+class APIViewsTestCase(SimpleTestCase):
+    def test_renders_with_tag_overrides(self):
+        api_endpoint = reverse("pattern_library:render_pattern_api")
+        response = self.client.post(
+            api_endpoint,
+            content_type="application/json",
+            data={
+                "template_name": "patterns/molecules/button/button.html",
+                "config": {
+                    "context": {"target_page": {"title": "API"}},
+                    "tags": {"pageurl": {"target_page": {"raw": "/hello-api"}}},
+                },
+            },
+        )
+        self.assertContains(response, '/hello-api')
+
+    def test_404(self):
+        api_endpoint = reverse("pattern_library:render_pattern_api")
+        response = self.client.post(
+            api_endpoint,
+            content_type="application/json",
+            data={
+                "template_name": "doesnotexist.html",
+                "config": {},
+            },
+        )
+        self.assertEqual(response.status_code, 404)