From 3a1099e33080e42e7f4f17e9c91b9576ff912627 Mon Sep 17 00:00:00 2001
From: Karl Hobley <karl@torchbox.com>
Date: Wed, 27 Aug 2014 10:54:58 +0100
Subject: [PATCH] Make hooks and image formats importing work with Django 1.7
 AppConfigs

This also fixes #398
---
 wagtail/tests/settings.py        | 10 ++++++++-
 wagtail/utils/apps.py            | 35 ++++++++++++++++++++++++++++++++
 wagtail/wagtailcore/hooks.py     | 15 +++-----------
 wagtail/wagtailimages/formats.py | 14 ++-----------
 4 files changed, 49 insertions(+), 25 deletions(-)
 create mode 100644 wagtail/utils/apps.py

diff --git a/wagtail/tests/settings.py b/wagtail/tests/settings.py
index 32426dba64..da8863e668 100644
--- a/wagtail/tests/settings.py
+++ b/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 = {
diff --git a/wagtail/utils/apps.py b/wagtail/utils/apps.py
new file mode 100644
index 0000000000..05bf8aa756
--- /dev/null
+++ b/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))
diff --git a/wagtail/wagtailcore/hooks.py b/wagtail/wagtailcore/hooks.py
index 958675b973..41955b9d30 100644
--- a/wagtail/wagtailcore/hooks.py
+++ b/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
 
 
diff --git a/wagtail/wagtailimages/formats.py b/wagtail/wagtailimages/formats.py
index d00b65b44d..3c5644a078 100644
--- a/wagtail/wagtailimages/formats.py
+++ b/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