WIP - Integrate 2 tuples solution for error codes

This is still a wip, the code is uggly and will need to be
refactored and reviewed a lot!

rest_framework/exceptions.py

@@ -58,22 +58,74 @@ class APIException(Exception):
         return self.detail
 
 
+def build_error_from_django_validation_error(exc_info):
+    code = getattr(exc_info, 'code', None) or 'invalid'
+    return [
+        (msg, code)
+        for msg in exc_info.messages
+    ]
+
 # The recommended style for using `ValidationError` is to keep it namespaced
 # under `serializers`, in order to minimize potential confusion with Django's
 # built in `ValidationError`. For example:
 #
 # from rest_framework import serializers
 # raise serializers.ValidationError('Value was invalid')
+
+
 class ValidationError(APIException):
     status_code = status.HTTP_400_BAD_REQUEST
+    code = None
 
     def __init__(self, detail, code=None):
         # 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):
-            detail = [detail]
-        self.detail = _force_text_recursive(detail)
-        self.code = code
+
+        if code:
+            self.full_details = [(detail, code)]
+        else:
+            self.full_details = detail
+
+        if isinstance(self.full_details, tuple):
+            self.detail, self.code = self.full_details
+            self.detail = [self.detail]
+
+        elif isinstance(self.full_details, list):
+            if isinstance(self.full_details, ReturnList):
+                self.detail = ReturnList(serializer=self.full_details.serializer)
+            else:
+                self.detail = []
+            for error in self.full_details:
+                if isinstance(error, tuple):
+                    message, code = error
+                    self.detail.append(message)
+                elif isinstance(error, dict):
+                    self.detail = self.full_details
+                    break
+
+        elif isinstance(self.full_details, dict):
+            if isinstance(self.full_details, ReturnDict):
+                self.detail = ReturnDict(serializer=self.full_details.serializer)
+            else:
+                self.detail = {}
+
+            for field_name, errors in self.full_details.items():
+                self.detail[field_name] = []
+                if isinstance(errors, tuple):
+                    message, code = errors
+                    self.detail[field_name].append(message)
+                elif isinstance(errors, list):
+                    for error in errors:
+                        if isinstance(error, tuple):
+                            message, code = error
+                        else:
+                            message = error
+                        if message:
+                            self.detail[field_name].append(message)
+        else:
+            self.detail = [self.full_details]
+
+        self.detail = _force_text_recursive(self.detail)
 
     def __str__(self):
         return six.text_type(self.detail)

rest_framework/fields.py

@@ -31,7 +31,9 @@ from rest_framework.compat import (
     MinValueValidator, duration_string, parse_duration, unicode_repr,
     unicode_to_repr
 )
-from rest_framework.exceptions import ValidationError
+from rest_framework.exceptions import (
+    ValidationError, build_error_from_django_validation_error
+)
 from rest_framework.settings import api_settings
 from rest_framework.utils import html, humanize_datetime, representation
 
@@ -501,9 +503,9 @@ class Field(object):
                 # attempting to accumulate a list of errors.
                 if isinstance(exc.detail, dict):
                     raise
-                errors.extend(exc.detail)
+                errors.append((exc.detail, exc.code))
             except DjangoValidationError as exc:
-                errors.extend(exc.messages)
+                errors.extend(build_error_from_django_validation_error(exc))
         if errors:
             raise ValidationError(errors)
 

rest_framework/serializers.py

@@ -23,6 +23,7 @@ from django.utils.translation import ugettext_lazy as _
 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 build_error_from_django_validation_error
 from rest_framework.utils import model_meta
 from rest_framework.utils.field_mapping import (
     ClassLookupDict, get_field_kwargs, get_nested_relation_kwargs,
@@ -213,12 +214,12 @@ class BaseSerializer(Field):
                 self._validated_data = self.run_validation(self.initial_data)
             except ValidationError as exc:
                 self._validated_data = {}
-                self._errors = exc.detail
+                self._errors = exc.full_details
             else:
                 self._errors = {}
 
         if self._errors and raise_exception:
-            raise ValidationError(self.errors)
+            raise ValidationError(self._errors)
 
         return not bool(self._errors)
 
@@ -248,7 +249,36 @@ class BaseSerializer(Field):
         if not hasattr(self, '_errors'):
             msg = 'You must call `.is_valid()` before accessing `.errors`.'
             raise AssertionError(msg)
-        return self._errors
+
+        if isinstance(self._errors, dict):
+            errors = ReturnDict(serializer=self)
+            for key, value in self._errors.items():
+                if isinstance(value, dict):
+                    errors[key] = {}
+                    for key_, value_ in value.items():
+                        message, code = value_[0]
+                        errors[key][key_] = [message]
+                elif isinstance(value, list):
+                    if isinstance(value[0], tuple):
+                        message, code = value[0]
+                    else:
+                        message = value[0]
+                    if isinstance(message, list):
+                        errors[key] = message
+                    else:
+                        errors[key] = [message]
+                elif isinstance(value, tuple):
+                    message, code = value
+                    errors[key] = [message]
+                else:
+                    errors[key] = [value]
+        elif isinstance(self._errors, list):
+            errors = ReturnList(self._errors, serializer=self)
+        else:
+            # This shouldn't ever happen.
+            errors = self._errors
+
+        return errors
 
     @property
     def validated_data(self):
@@ -299,24 +329,25 @@ def get_validation_error_detail(exc):
         # inside your codebase, but we handle Django's validation
         # exception class as well for simpler compat.
         # Eg. Calling Model.clean() explicitly inside Serializer.validate()
+        error = build_error_from_django_validation_error(exc)
         return {
-            api_settings.NON_FIELD_ERRORS_KEY: list(exc.messages)
+            api_settings.NON_FIELD_ERRORS_KEY: error
         }
-    elif isinstance(exc.detail, dict):
+    elif isinstance(exc.full_details, dict):
         # If errors may be a dict we use the standard {key: list of values}.
         # Here we ensure that all the values are *lists* of errors.
         return {
             key: value if isinstance(value, list) else [value]
-            for key, value in exc.detail.items()
+            for key, value in exc.full_details.items()
         }
-    elif isinstance(exc.detail, list):
+    elif isinstance(exc.full_details, list):
         # Errors raised as a list are non-field errors.
         return {
-            api_settings.NON_FIELD_ERRORS_KEY: exc.detail
+            api_settings.NON_FIELD_ERRORS_KEY: exc.full_details
         }
     # Errors raised as a string are non-field errors.
     return {
-        api_settings.NON_FIELD_ERRORS_KEY: [exc.detail]
+        api_settings.NON_FIELD_ERRORS_KEY: [exc.full_details]
     }
 
 
@@ -422,12 +453,13 @@ class Serializer(BaseSerializer):
             message = self.error_messages['invalid'].format(
                 datatype=type(data).__name__
             )
+            code = 'invalid'
             raise ValidationError({
-                api_settings.NON_FIELD_ERRORS_KEY: [message]
+                api_settings.NON_FIELD_ERRORS_KEY: [(message, code)]
             })
 
-        ret = OrderedDict()
-        errors = OrderedDict()
+        ret = ReturnDict(serializer=self)
+        errors = ReturnDict(serializer=self)
         fields = self._writable_fields
 
         for field in fields:
@@ -438,9 +470,10 @@ class Serializer(BaseSerializer):
                 if validate_method is not None:
                     validated_value = validate_method(validated_value)
             except ValidationError as exc:
-                errors[field.field_name] = exc.detail
+                errors[field.field_name] = exc.full_details
             except DjangoValidationError as exc:
-                errors[field.field_name] = list(exc.messages)
+                error = build_error_from_django_validation_error(exc)
+                errors[field.field_name] = error
             except SkipField:
                 pass
             else:
@@ -575,14 +608,16 @@ class ListSerializer(BaseSerializer):
             message = self.error_messages['not_a_list'].format(
                 input_type=type(data).__name__
             )
+            code = 'not_a_list'
             raise ValidationError({
-                api_settings.NON_FIELD_ERRORS_KEY: [message]
+                api_settings.NON_FIELD_ERRORS_KEY: [(message, code)]
             })
 
         if not self.allow_empty and len(data) == 0:
             message = self.error_messages['empty']
+            code = 'empty_not_allowed'
             raise ValidationError({
-                api_settings.NON_FIELD_ERRORS_KEY: [message]
+                api_settings.NON_FIELD_ERRORS_KEY: [(message, code)]
             })
 
         ret = []

rest_framework/validators.py

@@ -100,8 +100,9 @@ class UniqueTogetherValidator(object):
         if self.instance is not None:
             return
 
+        code = 'required'
         missing = {
-            field_name: self.missing_message
+            field_name: [(self.missing_message, code)]
             for field_name in self.fields
             if field_name not in attrs
         }
@@ -186,8 +187,9 @@ class BaseUniqueForValidator(object):
         The `UniqueFor<Range>Validator` classes always force an implied
         'required' state on the fields they are applied to.
         """
+        code = 'required'
         missing = {
-            field_name: self.missing_message
+            field_name: [(self.missing_message, code)]
             for field_name in [self.field, self.date_field]
             if field_name not in attrs
         }
@@ -213,9 +215,8 @@ class BaseUniqueForValidator(object):
         queryset = self.exclude_current_instance(attrs, queryset)
         if queryset.exists():
             message = self.message.format(date_field=self.date_field)
-            raise ValidationError({
-                self.field: message,
-            })
+            code = 'unique'
+            raise ValidationError({self.field: [(message, code)]})
 
     def __repr__(self):
         return unicode_to_repr('<%s(queryset=%s, field=%s, date_field=%s)>' % (

tests/test_validation_error.py

@@ -31,12 +31,12 @@ class TestValidationErrorWithCode(TestCase):
 
         def exception_handler(exc, request):
             return_errors = {}
-            for field_name, errors in exc.detail.items():
+            for field_name, errors in exc.full_details.items():
                 return_errors[field_name] = []
-                for error in errors:
+                for message, code in errors:
                     return_errors[field_name].append({
-                        'code': error.code,
-                        'message': error
+                        'code': code,
+                        'message': message
                     })
 
             return Response(return_errors, status=status.HTTP_400_BAD_REQUEST)