Fixed #3257 -- Added newforms ModelChoiceField and ModelMultipleChoiceField, which are now used by form_for_model() and form_for_instance(). Thanks for the patch, Honza Kral, floguy@gmail.com and kilian.cavalotti

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4547 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/fields/related.py

@@ -553,9 +553,9 @@ class ForeignKey(RelatedField, Field):
         setattr(cls, related.get_accessor_name(), ForeignRelatedObjectsDescriptor(related))
 
     def formfield(self, **kwargs):
-        defaults = {'choices': self.get_choices_default(), 'required': not self.blank, 'label': capfirst(self.verbose_name), 'help_text': self.help_text}
+        defaults = {'queryset': self.rel.to._default_manager.all(), 'required': not self.blank, 'label': capfirst(self.verbose_name), 'help_text': self.help_text}
         defaults.update(kwargs)
-        return forms.ChoiceField(**defaults)
+        return forms.ModelChoiceField(**defaults)
 
 class OneToOneField(RelatedField, IntegerField):
     def __init__(self, to, to_field=None, **kwargs):
@@ -619,9 +619,9 @@ class OneToOneField(RelatedField, IntegerField):
             cls._meta.one_to_one_field = self
 
     def formfield(self, **kwargs):
-        defaults = {'choices': self.get_choices_default(), 'required': not self.blank, 'label': capfirst(self.verbose_name), 'help_text': self.help_text}
+        defaults = {'queryset': self.rel.to._default_manager.all(), 'required': not self.blank, 'label': capfirst(self.verbose_name), 'help_text': self.help_text}
         defaults.update(kwargs)
-        return forms.ChoiceField(**kwargs)
+        return forms.ModelChoiceField(**kwargs)
 
 class ManyToManyField(RelatedField, Field):
     def __init__(self, to, **kwargs):
@@ -742,9 +742,9 @@ class ManyToManyField(RelatedField, Field):
         # MultipleChoiceField takes a list of IDs.
         if kwargs.get('initial') is not None:
             kwargs['initial'] = [i._get_pk_val() for i in kwargs['initial']]
-        defaults = {'choices': self.get_choices_default(), 'required': not self.blank, 'label': capfirst(self.verbose_name), 'help_text': self.help_text}
+        defaults = {'queryset' : self.rel.to._default_manager.all(), 'required': not self.blank, 'label': capfirst(self.verbose_name), 'help_text': self.help_text}
         defaults.update(kwargs)
-        return forms.MultipleChoiceField(**defaults)
+        return forms.ModelMultipleChoiceField(**defaults)
 
 class ManyToOneRel(object):
     def __init__(self, to, field_name, num_in_admin=3, min_num_in_admin=None,

django/newforms/models.py

@@ -4,8 +4,11 @@ and database field objects.
 """
 
 from forms import BaseForm, DeclarativeFieldsMetaclass, SortedDictFromList
+from fields import ChoiceField, MultipleChoiceField
+from widgets import Select, SelectMultiple
 
-__all__ = ('save_instance', 'form_for_model', 'form_for_instance', 'form_for_fields')
+__all__ = ('save_instance', 'form_for_model', 'form_for_instance', 'form_for_fields',
+           'ModelChoiceField', 'ModelMultipleChoiceField')
 
 def model_save(self, commit=True):
     """
@@ -33,7 +36,7 @@ def save_instance(form, instance, commit=True):
     for f in opts.fields:
         if isinstance(f, models.AutoField):
             continue
-        setattr(instance, f.attname, clean_data[f.name])
+        setattr(instance, f.name, clean_data[f.name])
     if commit:
         instance.save()
         for f in opts.many_to_many:
@@ -96,3 +99,34 @@ def form_for_fields(field_list):
     "Returns a Form class for the given list of Django database field instances."
     fields = SortedDictFromList([(f.name, f.formfield()) for f in field_list])
     return type('FormForFields', (BaseForm,), {'base_fields': fields})
+
+class ModelChoiceField(ChoiceField):
+    "A ChoiceField whose choices are a model QuerySet."
+    def __init__(self, queryset, empty_label=u"---------", **kwargs):
+        self.model = queryset.model
+        choices = [(obj._get_pk_val(), str(obj)) for obj in queryset]
+        if empty_label is not None:
+            choices = [(u"", empty_label)] + choices
+        ChoiceField.__init__(self, choices=choices, **kwargs)
+
+    def clean(self, value):
+        value = ChoiceField.clean(self, value)
+        if not value:
+            return None
+        try:
+            value = self.model._default_manager.get(pk=value)
+        except self.model.DoesNotExist:
+            raise ValidationError(gettext(u'Select a valid choice. That choice is not one of the available choices.'))
+        return value
+
+class ModelMultipleChoiceField(MultipleChoiceField):
+    "A MultipleChoiceField whose choices are a model QuerySet."
+    def __init__(self, queryset, **kwargs):
+        self.model = queryset.model
+        MultipleChoiceField.__init__(self, choices=[(obj._get_pk_val(), str(obj)) for obj in queryset], **kwargs)
+
+    def clean(self, value):
+        value = MultipleChoiceField.clean(self, value)
+        if not value:
+            return []
+        return self.model._default_manager.filter(pk__in=value)

tests/modeltests/model_forms/models.py

@@ -281,4 +281,86 @@ existing Category instance.
 <Category: Third>
 >>> Category.objects.get(id=3)
 <Category: Third>
+
+# ModelChoiceField ############################################################
+
+>>> from django.newforms import ModelChoiceField, ModelMultipleChoiceField
+
+>>> f = ModelChoiceField(Category.objects.all())
+>>> f.clean('')
+Traceback (most recent call last):
+...
+ValidationError: [u'This field is required.']
+>>> f.clean(None)
+Traceback (most recent call last):
+...
+ValidationError: [u'This field is required.']
+>>> f.clean(0)
+Traceback (most recent call last):
+...
+ValidationError: [u'Select a valid choice. That choice is not one of the available choices.']
+>>> f.clean(3)
+<Category: Third>
+>>> f.clean(2)
+<Category: It's a test>
+
+>>> f = ModelChoiceField(Category.objects.filter(pk=1), required=False)
+>>> print f.clean('')
+None
+>>> f.clean('')
+>>> f.clean('1')
+<Category: Entertainment>
+>>> f.clean('2')
+Traceback (most recent call last):
+...
+ValidationError: [u'Select a valid choice. That choice is not one of the available choices.']
+
+# ModelMultipleChoiceField ####################################################
+
+>>> f = ModelMultipleChoiceField(Category.objects.all())
+>>> f.clean(None)
+Traceback (most recent call last):
+...
+ValidationError: [u'This field is required.']
+>>> f.clean([])
+Traceback (most recent call last):
+...
+ValidationError: [u'This field is required.']
+>>> f.clean([1])
+[<Category: Entertainment>]
+>>> f.clean([2])
+[<Category: It's a test>]
+>>> f.clean(['1'])
+[<Category: Entertainment>]
+>>> f.clean(['1', '2'])
+[<Category: Entertainment>, <Category: It's a test>]
+>>> f.clean([1, '2'])
+[<Category: Entertainment>, <Category: It's a test>]
+>>> f.clean((1, '2'))
+[<Category: Entertainment>, <Category: It's a test>]
+>>> f.clean(['nonexistent'])
+Traceback (most recent call last):
+...
+ValidationError: [u'Select a valid choice. nonexistent is not one of the available choices.']
+>>> f.clean('hello')
+Traceback (most recent call last):
+...
+ValidationError: [u'Enter a list of values.']
+>>> f = ModelMultipleChoiceField(Category.objects.all(), required=False)
+>>> f.clean([])
+[]
+>>> f.clean(())
+[]
+>>> f.clean(['4'])
+Traceback (most recent call last):
+...
+ValidationError: [u'Select a valid choice. 4 is not one of the available choices.']
+>>> f.clean(['3', '4'])
+Traceback (most recent call last):
+...
+ValidationError: [u'Select a valid choice. 4 is not one of the available choices.']
+>>> f.clean(['1', '5'])
+Traceback (most recent call last):
+...
+ValidationError: [u'Select a valid choice. 5 is not one of the available choices.']
 """}