Make hooks and image formats importing work with Django 1.7 AppConfigs

This also fixes #398

wagtail/tests/settings.py

@@ -68,7 +68,6 @@ INSTALLED_APPS = [
     'wagtail.wagtailimages',
     'wagtail.wagtailembeds',
     'wagtail.wagtailsearch',
-    'wagtail.wagtailredirects',
     'wagtail.wagtailforms',
     'wagtail.contrib.wagtailstyleguide',
     'wagtail.contrib.wagtailsitemaps',
@@ -81,6 +80,15 @@ if django.VERSION[:2] == (1, 6):
     INSTALLED_APPS.append('south')
 
 
+# If we are using Django 1.7 install wagtailredirects with its appconfig
+# Theres nothing special about wagtailredirects, we just need to have one
+# app which uses AppConfigs to test that hooks load properly
+
+if django.VERSION[:2] == (1, 6):
+    INSTALLED_APPS.append('wagtail.wagtailredirects')
+else:
+    INSTALLED_APPS.append('wagtail.wagtailredirects.apps.WagtailRedirectsAppConfig')
+
 # As we don't have south migrations for tests, South thinks
 # the Django 1.7 migrations are South migrations.
 SOUTH_MIGRATION_MODULES = {

wagtail/utils/apps.py

@@ -0,0 +1,35 @@
+try:
+    from importlib import import_module
+except ImportError:
+    # for Python 2.6, fall back on django.utils.importlib (deprecated as of Django 1.7)
+    from django.utils.importlib import import_module
+
+import django
+from django.conf import settings
+from django.utils.module_loading import module_has_submodule
+
+
+def get_app_modules():
+    """
+    Generator function that yields a module object for each installed app
+    yields tuples of (app_name, module)
+    """
+    if django.VERSION[:2] == (1, 6):
+        # Django 1.6
+        for app in settings.INSTALLED_APPS:
+            yield app, import_module(app)
+    else:
+        # Django 1.7+
+        from django.apps import apps
+        for app in apps.get_app_configs():
+            yield app.name, app.module
+
+
+def get_app_submodules(submodule_name):
+    """
+    Searches each app module for the specified submodule
+    yields tuples of (app_name, module)
+    """
+    for name, module in get_app_modules():
+        if module_has_submodule(module, submodule_name):
+            yield name, import_module('%s.%s' % (name, submodule_name))

wagtail/wagtailcore/hooks.py

@@ -1,9 +1,5 @@
-from django.conf import settings
-try:
-    from importlib import import_module
-except ImportError:
-    # for Python 2.6, fall back on django.utils.importlib (deprecated as of Django 1.7)
-    from django.utils.importlib import import_module
+from wagtail.utils.apps import get_app_submodules
+
 
 _hooks = {}
 
@@ -40,12 +36,7 @@ _searched_for_hooks = False
 def search_for_hooks():
     global _searched_for_hooks
     if not _searched_for_hooks:
-        for app_module in settings.INSTALLED_APPS:
-            try:
-                import_module('%s.wagtail_hooks' % app_module)
-            except ImportError:
-                continue
-
+        list(get_app_submodules('wagtail_hooks'))
         _searched_for_hooks = True
 
 

wagtail/wagtailimages/formats.py

@@ -1,11 +1,6 @@
-from django.conf import settings
 from django.utils.html import escape
 
-try:
-    from importlib import import_module
-except ImportError:
-    # for Python 2.6, fall back on django.utils.importlib (deprecated as of Django 1.7)
-    from django.utils.importlib import import_module
+from wagtail.utils.apps import get_app_submodules
 
 
 class Format(object):
@@ -85,12 +80,7 @@ _searched_for_image_formats = False
 def search_for_image_formats():
     global _searched_for_image_formats
     if not _searched_for_image_formats:
-        for app_module in settings.INSTALLED_APPS:
-            try:
-                import_module('%s.image_formats' % app_module)
-            except ImportError:
-                continue
-
+        list(get_app_submodules('image_formats'))
         _searched_for_image_formats = True