Load templates from template engines’ DIRS setting

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Added
 
 - We now officially support Django 3.2, and tentatively Django 4.0
+- Load templates from template engines’ [`DIRS`](https://docs.djangoproject.com/en/3.2/ref/settings/#dirs) as well as apps’ `templates` subdirectories.
 
 ### Fixed
 

docs/reference/api.md

@@ -59,7 +59,7 @@ PATTERN_LIBRARY = {
 ### `SECTIONS`
 
 `SECTIONS` controls the groups of templates that appear in the navigation.
-The keys are the group titles and the values are lists of template name prefixes that will be searched to populate the groups.
+The keys are the group titles and the values are lists of template name prefixes that will be searched to populate the groups. The pattern library searches for templates both in [`DIRS`](https://docs.djangoproject.com/en/3.2/ref/settings/#dirs) directories for template engines, and in the `templates` subdirectory inside each installed application if using [`APP_DIRS`](https://docs.djangoproject.com/en/3.2/ref/settings/#app-dirs).
 
 You can use this to create basic two-folder "includes and pages" hierarchies:
 

pattern_library/utils.py

@@ -2,6 +2,7 @@
 import os
 import re
 
+from django.conf import settings
 from django.template import TemplateDoesNotExist
 from django.template.context import Context
 from django.template.loader import get_template, render_to_string
@@ -66,9 +67,16 @@ def order_dict(dictionary, key_sort=None):
     return dict(values)
 
 
+def get_template_dirs():
+    template_dirs = [d for engines in settings.TEMPLATES for d in engines.get("DIRS", [])]
+    template_app_dirs = get_app_template_dirs('templates')
+    template_dirs += template_app_dirs
+    return template_dirs
+
+
 def get_pattern_templates():
     templates = base_dict()
-    template_dirs = get_app_template_dirs('templates')
+    template_dirs = get_template_dirs()
 
     for lookup_dir in template_dirs:
         for root, dirs, files in os.walk(lookup_dir, topdown=True):

tests/tests/test_utils.py

@@ -1,6 +1,9 @@
-from django.test import SimpleTestCase
+import os
 
-from pattern_library.utils import get_template_ancestors
+from django.conf import settings
+from django.test import SimpleTestCase, override_settings
+
+from pattern_library.utils import get_template_ancestors, get_template_dirs
 
 
 class TestGetTemplateAncestors(SimpleTestCase):
@@ -33,3 +36,46 @@ def test_parent_template_from_variable(self):
                 'patterns/base.html',
             ],
         )
+
+
+class TestGetTemplateDirs(SimpleTestCase):
+    def get_relative_template_dirs(self):
+        """Make paths relative with a predefined root so we can use them in assertions."""
+        base = os.path.dirname(settings.BASE_DIR)
+        dirs = get_template_dirs()
+        return ['/'.join(str(d).replace(base, 'dpl').split('/')[-4:-1]) for d in dirs]
+
+    @override_settings(TEMPLATES=[
+        {
+            'BACKEND': 'django.template.backends.django.DjangoTemplates',
+            'APP_DIRS': True,
+        },
+    ])
+    def test_get_template_dirs_app_dirs(self):
+        self.assertListEqual(self.get_relative_template_dirs(), [
+            'django/contrib/auth',
+            'dpl/pattern_library',
+            'dpl/tests',
+        ])
+
+    @override_settings(TEMPLATES=[
+        {
+            'NAME': 'one',
+            'BACKEND': 'django.template.backends.django.DjangoTemplates',
+            'DIRS': [os.path.join(settings.BASE_DIR, "test_one", "templates")],
+            'APP_DIRS': True,
+        },
+        {
+            'NAME': 'two',
+            'BACKEND': 'django.template.backends.django.DjangoTemplates',
+            'DIRS': [os.path.join(settings.BASE_DIR, "test_two", "templates")],
+        },
+    ])
+    def test_get_template_dirs_list_dirs(self):
+        self.assertListEqual(self.get_relative_template_dirs(), [
+            'dpl/tests/test_one',
+            'dpl/tests/test_two',
+            'django/contrib/auth',
+            'dpl/pattern_library',
+            'dpl/tests',
+        ])