[soc2009/model-validation] Added min and max length validator. CharField now validates it's value's length using a validator.

git-svn-id: http://code.djangoproject.com/svn/django/branches/soc2009/model-validation@11194 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/validators.py

@@ -40,6 +40,7 @@ def validate_ipv4_address(value):
             code="invalid"
         )
 
+
 class MaxValueValidator(object):
     def __init__(self, max_value):
         self.max_value = max_value
@@ -51,6 +52,7 @@ class MaxValueValidator(object):
                 code='max_value',
                 params=(self.max_value,)
             )
+
 class MinValueValidator(object):
     def __init__(self, min_value):
         self.min_value = min_value
@@ -63,6 +65,32 @@ class MinValueValidator(object):
                 params=(self.min_value,)
             )
 
+class MinLengthValidator(object):
+    def __init__(self, min_length):
+        self.min_length = min_length
+
+    def __call__(self, value):
+        value_len = len(value)
+        if value_len < self.min_length:
+            raise ValidationError(
+                _(u'Ensure this value has at least %(min)d characters (it has %(length)d).'),
+                code='min_length',
+                params={ 'min': self.min_length, 'length': value_len}
+            )
+
+class MaxLengthValidator(object):
+    def __init__(self, max_length):
+        self.max_length = max_length
+
+    def __call__(self, value):
+        value_len = len(value)
+        if value_len > self.max_length:
+            raise ValidationError(
+                _(u'Ensure this value has at most %(max)d characters (it has %(length)d).'),
+                code='max_length',
+                params={ 'max': self.max_length, 'length': value_len}
+            )
+
 class ComplexValidator(object):
     def get_value(self, name, all_values, obj):
         assert all_values or obj, "Either all_values or obj must be supplied"

django/db/models/fields/__init__.py

@@ -469,6 +469,10 @@ class BooleanField(Field):
         return super(BooleanField, self).formfield(**defaults)
 
 class CharField(Field):
+    def __init__(self, *args, **kwargs):
+        super(CharField, self).__init__(*args, **kwargs)
+        self.validators.append(validators.MaxLengthValidator(self.max_length))
+
     def get_internal_type(self):
         return "CharField"
 
@@ -478,6 +482,9 @@ class CharField(Field):
         return smart_unicode(value)
 
     def formfield(self, **kwargs):
+        # passing of max_length to forms.CharField means that the value's length
+        # will be validated twice. This is considered acceptable since we want
+        # the value in the form field (to pass into widget for example).
         defaults = {'max_length': self.max_length}
         defaults.update(kwargs)
         return super(CharField, self).formfield(**defaults)

django/forms/fields.py

@@ -172,6 +172,11 @@ class CharField(Field):
     def __init__(self, max_length=None, min_length=None, *args, **kwargs):
         self.max_length, self.min_length = max_length, min_length
         super(CharField, self).__init__(*args, **kwargs)
+        # TODO: use this as soon as you make regex validator and use it in RegexField
+        #if min_length is not None:
+        #    self.validators.append(validators.MinLengthValidator(min_length))
+        #if max_length is not None:
+        #    self.validators.append(validators.MaxLengthValidator(max_length))
 
     def to_python(self, value):
         "Returns a Unicode object."

tests/modeltests/validation/tests.py

@@ -39,6 +39,10 @@ class BaseModelValidationTests(ValidationTestCase):
         mtv = ModelToValidate(number=10, name='Some Name', email='valid@email.com')
         self.assertEqual(None, mtv.clean())
 
+    def test_text_greater_that_charfields_max_length_eaises_erros(self):
+        mtv = ModelToValidate(number=10, name='Some Name'*100)
+        self.assertFailsValidation(mtv.clean, ['name',])
+
 class GetUniqueCheckTests(unittest.TestCase):
     def test_unique_fields_get_collected(self):
         m = UniqueFieldsModel()