Lazy load django's get_model (Closes #228).

Loading this function will, on pre-1.8 versions, load Django settings.
We'll lazy-load it to avoid crashes when Django hasn't been configured
yet (e.g in auto-discovery test setups).

2 files changed, 27 insertions, 8 deletions

diff --git a/docs/changelog.rst b/docs/changelog.rst
index 01d5775..24c01aa 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -21,6 +21,7 @@ ChangeLog
 
     - :issue:`201`: Properly handle custom Django managers when dealing with abstract Django models.
     - :issue:`212`: Fix :meth:`factory.django.mute_signals` to handle Django's signal caching
+    - :issue:`228`: Don't load :func:`django.apps.apps.get_model()` until required
 
 .. _v2.5.2:
 
diff --git a/factory/django.py b/factory/django.py
index b2af12c..b3c508c 100644
--- a/factory/django.py
+++ b/factory/django.py
@@ -56,16 +56,34 @@ def require_django():
         raise import_failure
 
 
-if django is None:
-    def get_model(app, model):
-        raise import_failure
+_LAZY_LOADS = {}
+
+def get_model(app, model):
+    """Wrapper around django's get_model."""
+    if 'get_model' not in _LAZY_LOADS:
+        _lazy_load_get_model()
+
+    _get_model = _LAZY_LOADS['get_model']
+    return _get_model(app, model)
+
+
+def _lazy_load_get_model():
+    """Lazy loading of get_model.
+
+    get_model loads django.conf.settings, which may fail if
+    the settings haven't been configured yet.
+    """
+    if django is None:
+        def get_model(app, model):
+            raise import_failure
 
-elif django.VERSION[:2] < (1, 7):
-    from django.db.models.loading import get_model
+    elif django.VERSION[:2] < (1, 7):
+        from django.db.models.loading import get_model
 
-else:
-    from django import apps as django_apps
-    get_model = django_apps.apps.get_model
+    else:
+        from django import apps as django_apps
+        get_model = django_apps.apps.get_model
+    _LAZY_LOADS['get_model'] = get_model
 
 
 class DjangoOptions(base.FactoryOptions):