Fixes #1812 -- Added model validity checks to ensure that models.py e…

…xists, and has been successfully imported for all INSTALLED_APPS. Previous behaviour was to silently ignore empty/problem models, which resulted in the display of an admin page that doesn't display a supposedly installed model. Thanks to Ian Holsman for the original report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@3201 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/management.py

@@ -803,9 +803,9 @@ def __init__(self, outfile=sys.stdout):
         self.errors = []
         self.outfile = outfile
 
-    def add(self, opts, error):
-        self.errors.append((opts, error))
-        self.outfile.write(style.ERROR("%s.%s: %s\n" % (opts.app_label, opts.module_name, error)))
+    def add(self, context, error):
+        self.errors.append((context, error))
+        self.outfile.write(style.ERROR("%s: %s\n" % (context, error)))
 
 def get_validation_errors(outfile, app=None):
     """
@@ -814,9 +814,14 @@ def get_validation_errors(outfile, app=None):
     Returns number of errors.
     """
     from django.db import models
+    from django.db.models.loading import get_app_errors
     from django.db.models.fields.related import RelatedObject
 
     e = ModelErrorCollection(outfile)
+
+    for (app_name, error) in get_app_errors().items():
+        e.add(app_name, error)
+
     for cls in models.get_models(app):
         opts = cls._meta
 

django/db/models/loading.py

@@ -10,6 +10,9 @@
 _app_models = {} # Dictionary of models against app label
                  # Each value is a dictionary of model name: model class
                  # Applabel and Model entry exists in cache when individual model is loaded.
+_app_errors = {} # Dictionary of errors that were experienced when loading the INSTALLED_APPS
+                 # Key is the app_name of the model, value is the exception that was raised
+                 # during model loading.
 _loaded = False  # Has the contents of settings.INSTALLED_APPS been loaded? 
                  # i.e., has get_apps() been called?
 
@@ -22,11 +25,9 @@ def get_apps():
         for app_name in settings.INSTALLED_APPS:
             try:
                 load_app(app_name)
-            except ImportError:
-                pass # Assume this app doesn't have a models.py in it.
-                     # GOTCHA: It may have a models.py that raises ImportError.
-            except AttributeError:
-                pass # This app doesn't have a models.py in it.
+            except Exception, e:
+                # Problem importing the app
+                _app_errors[app_name] = e
     return _app_list
 
 def get_app(app_label):
@@ -39,10 +40,17 @@ def get_app(app_label):
 
 def load_app(app_name):
     "Loads the app with the provided fully qualified name, and returns the model module."
+    global _app_list
     mod = __import__(app_name, '', '', ['models'])
     if mod.models not in _app_list:
         _app_list.append(mod.models)
     return mod.models
+
+def get_app_errors():
+    "Returns the map of known problems with the INSTALLED_APPS"
+    global _app_errors
+    get_apps() # Run get_apps() to populate the _app_list cache. Slightly hackish.
+    return _app_errors
 
 def get_models(app_mod=None):
     """

django/db/models/options.py

@@ -87,7 +87,10 @@ def add_field(self, field):
 
     def __repr__(self):
         return '<Options for %s>' % self.object_name
-
+
+    def __str__(self):
+        return "%s.%s" % (self.app_label, self.module_name)
+
     def get_field(self, name, many_to_many=True):
         "Returns the requested field by name. Raises FieldDoesNotExist on error."
         to_search = many_to_many and (self.fields + self.many_to_many) or self.fields