Resolves issue #71 for the admin interface by working around the use of modelform_fac...

[philo.git] / forms / entities.py

diff --git a/forms/entities.py b/forms/entities.py
index b6259a3..43094b9 100644 (file)
--- a/forms/entities.py
+++ b/forms/entities.py
@@ -1,4 +1,4 @@
-from django.forms.models import ModelFormMetaclass, ModelForm
+from django.forms.models import ModelFormMetaclass, ModelForm, ModelFormOptions
 from django.utils.datastructures import SortedDict
 from philo.utils import fattr
 
@@ -6,7 +6,7 @@ from philo.utils import fattr
 __all__ = ('EntityForm',)
 
 
-def proxy_fields_for_entity_model(entity_model, fields=None, exclude=None, widgets=None, formfield_callback=lambda f, **kwargs: f.formfield(**kwargs)):
+def proxy_fields_for_entity_model(entity_model, fields=None, exclude=None, widgets=None, formfield_callback=None):
        field_list = []
        ignored = []
        opts = entity_model._entity_meta
@@ -21,7 +21,14 @@ def proxy_fields_for_entity_model(entity_model, fields=None, exclude=None, widge
                        kwargs = {'widget': widgets[f.name]}
                else:
                        kwargs = {}
-               formfield = formfield_callback(f, **kwargs)
+               
+               if formfield_callback is None:
+                       formfield = f.formfield(**kwargs)
+               elif not callable(formfield_callback):
+                       raise TypeError('formfield_callback must be a function or callable')
+               else:
+                       formfield = formfield_callback(f, **kwargs)
+               
                if formfield:
                        field_list.append((f.name, formfield))
                else:
@@ -35,31 +42,66 @@ def proxy_fields_for_entity_model(entity_model, fields=None, exclude=None, widge
        return field_dict
 
 
-# BEGIN HACK - This will not be required after http://code.djangoproject.com/ticket/14082 has been resolved
-
-class EntityFormBase(ModelForm):
-       pass
-
-_old_metaclass_new = ModelFormMetaclass.__new__
-
-def _new_metaclass_new(cls, name, bases, attrs):
-       formfield_callback = attrs.get('formfield_callback', lambda f, **kwargs: f.formfield(**kwargs))
-       new_class = _old_metaclass_new(cls, name, bases, attrs)
-       opts = new_class._meta
-       if issubclass(new_class, EntityFormBase) and opts.model:
-               # "override" proxy fields with declared fields by excluding them if there's a name conflict.
-               exclude = (list(opts.exclude or []) + new_class.declared_fields.keys()) or None
-               proxy_fields = proxy_fields_for_entity_model(opts.model, opts.fields, exclude, opts.widgets, formfield_callback) # don't pass in formfield_callback
+class EntityFormMetaclass(ModelFormMetaclass):
+       def __new__(cls, name, bases, attrs):
+               try:
+                       parents = [b for b in bases if issubclass(b, EntityForm)]
+               except NameError:
+                       # We are defining EntityForm itself
+                       parents = None
+               sup = super(EntityFormMetaclass, cls)
+               
+               if not parents:
+                       # Then there's no business trying to use proxy fields.
+                       return sup.__new__(cls, name, bases, attrs)
+               
+               # Preemptively make a meta so we can screen out any proxy fields.
+               # After http://code.djangoproject.com/ticket/14082 has been resolved,
+               # perhaps switch to setting proxy fields as "declared"?
+               _opts = ModelFormOptions(attrs.get('Meta', None))
+               
+               # Make another copy of opts to spoof the proxy fields not being there.
+               opts = ModelFormOptions(attrs.get('Meta', None))
+               if opts.model:
+                       formfield_callback = attrs.get('formfield_callback', None)
+                       proxy_fields = proxy_fields_for_entity_model(opts.model, opts.fields, opts.exclude, opts.widgets, formfield_callback)
+               else:
+                       proxy_fields = {}
+               
+               # Screen out all proxy fields from the meta
+               opts.fields = list(opts.fields or [])
+               opts.exclude = list(opts.exclude or [])
+               
+               for field in proxy_fields.keys():
+                       try:
+                               opts.fields.remove(field)
+                       except ValueError:
+                               pass
+                       try:
+                               opts.exclude.remove(field)
+                       except ValueError:
+                               pass
+               opts.fields = opts.fields or None
+               opts.exclude = opts.exclude or None
+               
+               # Put in the new Meta.
+               attrs['Meta'] = opts
+               
+               new_class = sup.__new__(cls, name, bases, attrs)
+               
+               intersections = set(new_class.declared_fields.keys()) & set(proxy_fields.keys())
+               for key in intersections:
+                       proxy_fields.pop(key)
+               
                new_class.proxy_fields = proxy_fields
+               new_class._meta = _opts
                new_class.base_fields.update(proxy_fields)
-       return new_class
-
-ModelFormMetaclass.__new__ = staticmethod(_new_metaclass_new)
+               return new_class
 
-# END HACK
 
-
-class EntityForm(EntityFormBase): # Would inherit from ModelForm directly if it weren't for the above HACK
+class EntityForm(ModelForm):
+       __metaclass__ = EntityFormMetaclass
+       
        def __init__(self, *args, **kwargs):
                initial = kwargs.pop('initial', None)
                instance = kwargs.get('instance', None)