Fixed #17840 -- Generalized named placeholders in form error messages

Also fixed plural messages for DecimalField.

django/forms/fields.py

@@ -292,9 +292,18 @@ class FloatField(IntegerField):
 class DecimalField(IntegerField):
     default_error_messages = {
         'invalid': _('Enter a number.'),
-        'max_digits': _('Ensure that there are no more than %s digits in total.'),
-        'max_decimal_places': _('Ensure that there are no more than %s decimal places.'),
-        'max_whole_digits': _('Ensure that there are no more than %s digits before the decimal point.')
+        'max_digits': ungettext_lazy(
+            'Ensure that there are no more than %(max)s digit in total.',
+            'Ensure that there are no more than %(max)s digits in total.',
+            'max'),
+        'max_decimal_places': ungettext_lazy(
+            'Ensure that there are no more than %(max)s decimal place.',
+            'Ensure that there are no more than %(max)s decimal places.',
+            'max'),
+        'max_whole_digits': ungettext_lazy(
+            'Ensure that there are no more than %(max)s digit before the decimal point.',
+            'Ensure that there are no more than %(max)s digits before the decimal point.',
+            'max'),
     }
 
     def __init__(self, max_value=None, min_value=None, max_digits=None, decimal_places=None, *args, **kwargs):
@@ -341,11 +350,15 @@ class DecimalField(IntegerField):
         whole_digits = digits - decimals
 
         if self.max_digits is not None and digits > self.max_digits:
-            raise ValidationError(self.error_messages['max_digits'] % self.max_digits)
+            raise ValidationError(self.error_messages['max_digits'] % {
+                                  'max': self.max_digits})
         if self.decimal_places is not None and decimals > self.decimal_places:
-            raise ValidationError(self.error_messages['max_decimal_places'] % self.decimal_places)
-        if self.max_digits is not None and self.decimal_places is not None and whole_digits > (self.max_digits - self.decimal_places):
-            raise ValidationError(self.error_messages['max_whole_digits'] % (self.max_digits - self.decimal_places))
+            raise ValidationError(self.error_messages['max_decimal_places'] % {
+                                  'max': self.decimal_places})
+        if (self.max_digits is not None and self.decimal_places is not None
+                and whole_digits > (self.max_digits - self.decimal_places)):
+            raise ValidationError(self.error_messages['max_whole_digits'] % {
+                                  'max': (self.max_digits - self.decimal_places)})
         return value
 
     def widget_attrs(self, widget):

django/forms/models.py

@@ -1039,9 +1039,9 @@ class ModelMultipleChoiceField(ModelChoiceField):
     hidden_widget = MultipleHiddenInput
     default_error_messages = {
         'list': _('Enter a list of values.'),
-        'invalid_choice': _('Select a valid choice. %s is not one of the'
+        'invalid_choice': _('Select a valid choice. %(value)s is not one of the'
                             ' available choices.'),
-        'invalid_pk_value': _('"%s" is not a valid value for a primary key.')
+        'invalid_pk_value': _('"%(pk)s" is not a valid value for a primary key.')
     }
 
     def __init__(self, queryset, cache_choices=False, required=True,
@@ -1063,12 +1063,12 @@ class ModelMultipleChoiceField(ModelChoiceField):
             try:
                 self.queryset.filter(**{key: pk})
             except ValueError:
-                raise ValidationError(self.error_messages['invalid_pk_value'] % pk)
+                raise ValidationError(self.error_messages['invalid_pk_value'] % {'pk': pk})
         qs = self.queryset.filter(**{'%s__in' % key: value})
         pks = set([force_text(getattr(o, key)) for o in qs])
         for val in value:
             if force_text(val) not in pks:
-                raise ValidationError(self.error_messages['invalid_choice'] % val)
+                raise ValidationError(self.error_messages['invalid_choice'] % {'value': val})
         # Since this overrides the inherited ModelChoiceField.clean
         # we run custom validators here
         self.run_validators(value)

tests/forms_tests/tests/test_error_messages.py

@@ -60,9 +60,9 @@ class FormsErrorMessagesTestCase(TestCase, AssertFormErrorsMixin):
             'invalid': 'INVALID',
             'min_value': 'MIN VALUE IS %(limit_value)s',
             'max_value': 'MAX VALUE IS %(limit_value)s',
-            'max_digits': 'MAX DIGITS IS %s',
-            'max_decimal_places': 'MAX DP IS %s',
-            'max_whole_digits': 'MAX DIGITS BEFORE DP IS %s',
+            'max_digits': 'MAX DIGITS IS %(max)s',
+            'max_decimal_places': 'MAX DP IS %(max)s',
+            'max_whole_digits': 'MAX DIGITS BEFORE DP IS %(max)s',
         }
         f = DecimalField(min_value=5, max_value=10, error_messages=e)
         self.assertFormErrors(['REQUIRED'], f.clean, '')
@@ -254,7 +254,7 @@ class ModelChoiceFieldErrorMessagesTestCase(TestCase, AssertFormErrorsMixin):
         # ModelMultipleChoiceField
         e = {
             'required': 'REQUIRED',
-            'invalid_choice': '%s IS INVALID CHOICE',
+            'invalid_choice': '%(value)s IS INVALID CHOICE',
             'list': 'NOT A LIST OF VALUES',
         }
         f = ModelMultipleChoiceField(queryset=ChoiceModel.objects.all(), error_messages=e)