Modify ValidationError api

`ValidationErrorMessage` is now abstracted in `ValidationError`'s
constructor

rest_framework/authtoken/serializers.py

@@ -2,7 +2,6 @@ from django.contrib.auth import authenticate
 from django.utils.translation import ugettext_lazy as _
 
 from rest_framework import serializers
-from rest_framework.exceptions import ValidationErrorMessage
 
 
 class AuthTokenSerializer(serializers.Serializer):
@@ -20,24 +19,19 @@ class AuthTokenSerializer(serializers.Serializer):
                 if not user.is_active:
                     msg = _('User account is disabled.')
                     raise serializers.ValidationError(
-                        ValidationErrorMessage(
-                            msg,
-                            code='authorization')
-                    )
+                        msg,
+                        code='authorization')
             else:
                 msg = _('Unable to log in with provided credentials.')
                 raise serializers.ValidationError(
-                    ValidationErrorMessage(
-                        msg,
-                        code='authorization')
-                )
+                    msg,
+                    code='authorization')
+
         else:
             msg = _('Must include "username" and "password".')
             raise serializers.ValidationError(
-                ValidationErrorMessage(
-                    msg,
-                    code='authorization')
-            )
+                msg,
+                code='authorization')
 
         attrs['user'] = user
         return attrs

rest_framework/exceptions.py

@@ -87,7 +87,11 @@ class ValidationErrorMessage(six.text_type):
 class ValidationError(APIException):
     status_code = status.HTTP_400_BAD_REQUEST
 
-    def __init__(self, detail):
+    def __init__(self, detail, code=None):
+        # If code is there, this means we are dealing with a message.
+        if code and not isinstance(detail, ValidationErrorMessage):
+            detail = ValidationErrorMessage(detail, code=code)
+
         # For validation errors the 'detail' key is always required.
         # The details should always be coerced to a list if not already.
         if not isinstance(detail, dict) and not isinstance(detail, list):

rest_framework/fields.py

@@ -32,8 +32,7 @@ from rest_framework.compat import (
     unicode_to_repr
 )
 from rest_framework.exceptions import (
-    ValidationError, ValidationErrorMessage,
-    build_error_from_django_validation_error
+    ValidationError, build_error_from_django_validation_error
 )
 from rest_framework.settings import api_settings
 from rest_framework.utils import html, humanize_datetime, representation
@@ -546,7 +545,7 @@ class Field(object):
             msg = MISSING_ERROR_MESSAGE.format(class_name=class_name, key=key)
             raise AssertionError(msg)
         message_string = msg.format(**kwargs)
-        raise ValidationError(ValidationErrorMessage(message_string, code=key))
+        raise ValidationError(message_string, code=key)
 
     @cached_property
     def root(self):

rest_framework/serializers.py

@@ -24,6 +24,7 @@ from rest_framework import exceptions
 from rest_framework.compat import DurationField as ModelDurationField
 from rest_framework.compat import JSONField as ModelJSONField
 from rest_framework.compat import postgres_fields, unicode_to_repr
+from rest_framework.exceptions import ValidationErrorMessage
 from rest_framework.utils import model_meta
 from rest_framework.utils.field_mapping import (
     ClassLookupDict, get_field_kwargs, get_nested_relation_kwargs,

rest_framework/validators.py

@@ -60,8 +60,7 @@ class UniqueValidator(object):
         queryset = self.filter_queryset(value, queryset)
         queryset = self.exclude_current_instance(queryset)
         if queryset.exists():
-            raise ValidationError(ValidationErrorMessage(self.message,
-                                                         code='unique'))
+            raise ValidationError(self.message, code='unique')
 
     def __repr__(self):
         return unicode_to_repr('<%s(queryset=%s)>' % (
@@ -152,10 +151,8 @@ class UniqueTogetherValidator(object):
         if None not in checked_values and queryset.exists():
             field_names = ', '.join(self.fields)
             raise ValidationError(
-                ValidationErrorMessage(
-                    self.message.format(field_names=field_names),
-                    code='unique')
-            )
+                self.message.format(field_names=field_names),
+                code='unique')
 
     def __repr__(self):
         return unicode_to_repr('<%s(queryset=%s, fields=%s)>' % (