Ticket #12510: django-model-choice-field-validation.2.diff

django/forms/models.py

@@ -875 +875 @@
 
     choices = property(_get_choices, ChoiceField._set_choices)
 
-    def clean(self, value):
-        Field.clean(self, value)
+    def to_python(self, value):
         if value in EMPTY_VALUES:
             return None
         try:
@@ -886 +885 @@
             raise ValidationError(self.error_messages['invalid_choice'])
         return value
 
+    def validate(self, value):
+        return Field.validate(self, value)
+
 class ModelMultipleChoiceField(ModelChoiceField):
     """A MultipleChoiceField whose choices are a model QuerySet."""
     widget = SelectMultiple

tests/regressiontests/forms/models.py

@@ -41 +41 @@
 class FileForm(django_forms.Form):
     file1 = django_forms.FileField()
 
+class Group(models.Model):
+    name = models.CharField(max_length=10)
+
+    def __unicode__(self):
+        return self.name
+
+class SubGroup(models.Model):
+    group = models.ForeignKey(Group)
+    name = models.CharField(max_length=10)
+
+    def __unicode__(self):
+        return u'%s - %s' % (self.group.name, self.name)
+
 __test__ = {'API_TESTS': """
 >>> from django.forms.models import ModelForm
 >>> from django.core.files.uploadedfile import SimpleUploadedFile
@@ -131 +144 @@
 >>> list(ChoiceFieldForm().fields['choice'].choices)
 [(1, u'ChoiceOptionModel object')]
 
+It is not necessary to generate choices for ModelChoiceField (regression test for #12510).
+
+>>> group = Group.objects.create(name='test')
+>>> subgroups = [SubGroup.objects.create(group=group, name=name) for name in 'abcdefghij']
+
+>>> from django.conf import settings
+>>> from django import db
+
+>>> settings.DEBUG = True
+>>> db.reset_queries()
+
+>>> field = django_forms.ModelChoiceField(SubGroup.objects.order_by('-name'))
+>>> field.clean(subgroups[0].pk).name
+u'a'
+>>> len(db.connection.queries)
+1
+
+>>> settings.DEBUG = False
+
 """}