Initial raw_id_fields support for proxy fields. Involves hacks to bypass model valida...
[philo.git] / contrib / cowell / forms.py
1 from django.forms.models import ModelFormMetaclass, ModelForm
2 from django.utils.datastructures import SortedDict
3 from philo.utils import fattr
4
5
6 __all__ = ('ProxyFieldForm',)
7
8
9 def proxy_fields_for_entity_model(entity_model, fields=None, exclude=None, widgets=None, formfield_callback=lambda f, **kwargs: f.formfield(**kwargs)):
10         field_list = []
11         ignored = []
12         opts = entity_model._entity_meta
13         for f in opts.proxy_fields:
14                 if not f.editable:
15                         continue
16                 if fields and not f.name in fields:
17                         continue
18                 if exclude and f.name in exclude:
19                         continue
20                 if widgets and f.name in widgets:
21                         kwargs = {'widget': widgets[f.name]}
22                 else:
23                         kwargs = {}
24                 formfield = formfield_callback(f, **kwargs)
25                 if formfield:
26                         field_list.append((f.name, formfield))
27                 else:
28                         ignored.append(f.name)
29         field_dict = SortedDict(field_list)
30         if fields:
31                 field_dict = SortedDict(
32                         [(f, field_dict.get(f)) for f in fields
33                                 if ((not exclude) or (exclude and f not in exclude)) and (f not in ignored) and (f in field_dict)]
34                 )
35         return field_dict
36
37
38 # BEGIN HACK - This will not be required after http://code.djangoproject.com/ticket/14082 has been resolved
39
40 class ProxyFieldFormBase(ModelForm):
41         pass
42
43 _old_metaclass_new = ModelFormMetaclass.__new__
44
45 def _new_metaclass_new(cls, name, bases, attrs):
46         formfield_callback = attrs.get('formfield_callback', lambda f, **kwargs: f.formfield(**kwargs))
47         new_class = _old_metaclass_new(cls, name, bases, attrs)
48         opts = new_class._meta
49         if issubclass(new_class, ProxyFieldFormBase) and opts.model:
50                 # "override" proxy fields with declared fields by excluding them if there's a name conflict.
51                 exclude = (list(opts.exclude or []) + new_class.declared_fields.keys()) or None
52                 proxy_fields = proxy_fields_for_entity_model(opts.model, opts.fields, exclude, opts.widgets, formfield_callback) # don't pass in formfield_callback
53                 new_class.proxy_fields = proxy_fields
54                 new_class.base_fields.update(proxy_fields)
55         return new_class
56
57 ModelFormMetaclass.__new__ = staticmethod(_new_metaclass_new)
58
59 # END HACK
60
61
62 class ProxyFieldForm(ProxyFieldFormBase): # Would inherit from ModelForm directly if it weren't for the above HACK
63         def __init__(self, *args, **kwargs):
64                 initial = kwargs.pop('initial', None)
65                 instance = kwargs.get('instance', None)
66                 if instance is not None:
67                         new_initial = {}
68                         for f in instance._entity_meta.proxy_fields:
69                                 if self._meta.fields and not f.name in self._meta.fields:
70                                         continue
71                                 if self._meta.exclude and f.name in self._meta.exclude:
72                                         continue
73                                 new_initial[f.name] = f.value_from_object(instance)
74                 else:
75                         new_initial = {}
76                 if initial is not None:
77                         new_initial.update(initial)
78                 kwargs['initial'] = new_initial
79                 super(ProxyFieldForm, self).__init__(*args, **kwargs)
80         
81         @fattr(alters_data=True)
82         def save(self, commit=True):
83                 cleaned_data = self.cleaned_data
84                 instance = super(ProxyFieldForm, self).save(commit=False)
85                 
86                 for f in instance._entity_meta.proxy_fields:
87                         if not f.editable or not f.name in cleaned_data:
88                                 continue
89                         if self._meta.fields and f.name not in self._meta.fields:
90                                 continue
91                         if self._meta.exclude and f.name in self._meta.exclude:
92                                 continue
93                         setattr(instance, f.attname, cleaned_data[f.name])
94                 
95                 if commit:
96                         instance.save()
97                         self.save_m2m()
98                 
99                 return instance