Merged cowell back into core.

[philo.git] / forms / entities.py

diff --git a/forms/entities.py b/forms/entities.py
new file mode 100644 (file)
index 0000000..b6259a3
--- /dev/null
+++ b/forms/entities.py
@@ -0,0 +1,99 @@
+from django.forms.models import ModelFormMetaclass, ModelForm
+from django.utils.datastructures import SortedDict
+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)):
+       field_list = []
+       ignored = []
+       opts = entity_model._entity_meta
+       for f in opts.proxy_fields:
+               if not f.editable:
+                       continue
+               if fields and not f.name in fields:
+                       continue
+               if exclude and f.name in exclude:
+                       continue
+               if widgets and f.name in widgets:
+                       kwargs = {'widget': widgets[f.name]}
+               else:
+                       kwargs = {}
+               formfield = formfield_callback(f, **kwargs)
+               if formfield:
+                       field_list.append((f.name, formfield))
+               else:
+                       ignored.append(f.name)
+       field_dict = SortedDict(field_list)
+       if fields:
+               field_dict = SortedDict(
+                       [(f, field_dict.get(f)) for f in fields
+                               if ((not exclude) or (exclude and f not in exclude)) and (f not in ignored) and (f in field_dict)]
+               )
+       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
+               new_class.proxy_fields = proxy_fields
+               new_class.base_fields.update(proxy_fields)
+       return new_class
+
+ModelFormMetaclass.__new__ = staticmethod(_new_metaclass_new)
+
+# END HACK
+
+
+class EntityForm(EntityFormBase): # Would inherit from ModelForm directly if it weren't for the above HACK
+       def __init__(self, *args, **kwargs):
+               initial = kwargs.pop('initial', None)
+               instance = kwargs.get('instance', None)
+               if instance is not None:
+                       new_initial = {}
+                       for f in instance._entity_meta.proxy_fields:
+                               if self._meta.fields and not f.name in self._meta.fields:
+                                       continue
+                               if self._meta.exclude and f.name in self._meta.exclude:
+                                       continue
+                               new_initial[f.name] = f.value_from_object(instance)
+               else:
+                       new_initial = {}
+               if initial is not None:
+                       new_initial.update(initial)
+               kwargs['initial'] = new_initial
+               super(EntityForm, self).__init__(*args, **kwargs)
+       
+       @fattr(alters_data=True)
+       def save(self, commit=True):
+               cleaned_data = self.cleaned_data
+               instance = super(EntityForm, self).save(commit=False)
+               
+               for f in instance._entity_meta.proxy_fields:
+                       if not f.editable or not f.name in cleaned_data:
+                               continue
+                       if self._meta.fields and f.name not in self._meta.fields:
+                               continue
+                       if self._meta.exclude and f.name in self._meta.exclude:
+                               continue
+                       setattr(instance, f.attname, f.get_storage_value(cleaned_data[f.name]))
+               
+               if commit:
+                       instance.save()
+                       self.save_m2m()
+               
+               return instance
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