DRF Friendly Errors

Extension for Django REST framework error display

Overview

This package extends default error JSON body providing configurable error codes and more consumable response structure.

It turns default JSON body of HTTP 400 response, which look like this

{
    "name": ["This field is required."],
    "password": ["This field may not be blank."]
    "age": ["This field may not be null."]
    "description": ["Ensure this field has no more than 100 characters."]
}

into

{
    "code" : 1001,
    "message" : "Validation Failed",
    "errors" : [
        {
            "code" : 2002,
            "field" : "name",
            "message" : "This field is required."
        },
        {
            "code" : 2031,
            "field" : "password",
            "message" : "This field may not be blank."
        },
        {
            "code" : 2023,
            "field" : "age",
            "message" : "This field may not be null."
        },
        {
            "code" : 2041,
            "field" : "description",
            "message" : "Ensure this field has no more than 100 characters."
        },
    ]
}

Library handles all Django REST framework built-in serializer validation.

Requirements

Python (2.7, 3.4)
Django (1.8, 1.9)
Django REST framework (3.3)

Installation

By running installation script

$ python setup.py install

Or using pip

$ pip install drf-friendly-errors

Usage

Simply add a FriendlyErrorMessagesMixin to your serializer or model serializer class

from rest_framework_friendly_errors.mixins import FriendlyErrorMessagesMixin

class MySerializer(FriendlyErrorMessagesMixin, ModelSerializer):

If you want to change default library settings and provide your own set of error codes just add following in your settings.py

FRIENDLY_ERRORS = {
    FIELD_ERRORS = {
        'CharField': {'required': 10, 'null':11, 'blank': 12, 'max_length': 13, 'min_length': 14}
    }
    VALIDATOR_ERRORS = {
        'UniqueValidator': 50
    },
    EXCEPTION_DICT = {
        'PermissionDenied': 100
    }
}

Custom serializer validation

If you need custom field validation or validation for whole serializer register your validation in serializer class

class PostSerializer(FriendlyErrorMessagesMixin,
                     serializers.ModelSerializer):
    class Meta:
        model = Post

    def validate_title(self, value):
        if value[0] != value[0].upper():
            raise ValidationError('First letter must be an uppercase')
        return value

    def validate(self, attrs):
        category = attrs.get('category)
        title = attrs.get('title')
        if category and category not in title:
            raise ValidationError('Title has to include category')
        return attrs

    FIELD_VALIDATION_ERRORS = {'validate_title': 5000} # register your own validation method and assign it to error code
    NON_FIELD_ERRORS = {'Title has to include category': 8000} # register non field error messages and assign it to error code

If you want to raise field error in validate method use register_error method provided by a mixin

class PostSerializer(FriendlyErrorMessagesMixin,
                     serializers.ModelSerializer):
    class Meta:
        model = Post

    def validate(self, attrs):
        category = attrs.get('category')
        title = attrs.get('title')
        if category and category not in title:
            self.register_error(error_message='Title has to include category',
                                error_code=8000,
                                field_name='title')
        return attrs

Error codes not related to serializer validation

To turn other type of errors responses into friendly errors responses with error codes add this exception handler to your REST_FRAMEWORK settings

REST_FRAMEWORK = {
    'EXCEPTION_HANDLER':
    'rest_framework_friendly_errors.handlers.friendly_exception_handler'
}

Default error codes

Following conventions were used:

1xxx - Are reserved for non field errors

2xxx - Are reserved for field errors

3xxx - Are reserved for validator errors

4xxx - Are reserved for other errors not related to serializer validation

Default field error codes

Field is required

2001: BooleanField, NullBooleanField
2002: CharField, EmailField, RegexField, SlugField, URLField, UUIDField, FilePathField, IPAddressField
2003: IntegerField, FloatField, DecimalField
2004: ChoiceField, MultipleChoiceField
2005: FileField, ImageField
2006: ListField, DictField, JSONField
2007: StringRequiredField, PrimaryKeyRelatedField, HyperlinkedRelatedField, SlugRelatedField, HyperlinkedIdentityField, ManyRelatedField
2008: ReadOnlyField, HiddenField, ModelField, SerializerMethodField

Field data is invalid (invalid regex, string instead of number, date, etc.)

2011: BooleanField, NullBooleanField
2012: EmailField, RegexField, SlugField, URLField, UUIDField, IPAddressField
2013: IntegerField, FloatField, DecimalField
2014: FileField, ImageField
2015: DateTimeField, DateField, TimeField, DurationField

Field data cannot be null

2021: BooleanField, NullBooleanField
2022: CharField, EmailField, RegexField, SlugField, URLField, UUIDField, FilePathField, IPAddressField
2023: IntegerField, FloatField, DecimalField
2024: ChoiceField, MultipleChoiceField
2025: FileField, ImageField
2026: ListField, DictField, JSONField
2027: StringRequiredField, PrimaryKeyRelatedField, HyperlinkedRelatedField, SlugRelatedField, HyperlinkedIdentityField, ManyRelatedField
2028: ReadOnlyField, HiddenField, ModelField, SerializerMethodField

Field data cannot be blank

2031: CharField, EmailField, RegexField, SlugField, URLField, UUIDField, IPAddressField

Field data is too long string

2041: CharField, EmailField, RegexField, SlugField, URLField, UUIDField, IPAddressField
2042: IntegerField, FloatField, DecimalField
2043: FileField, ImageField

Field data is too short string

2051: CharField, EmailField, RegexField, SlugField, URLField, UUIDField, IPAddressField

Field data is too big number

2061: IntegerField, FloatField, DecimalField

Field data is too small number

2071: IntegerField, FloatField, DecimalField

Field data do not match any value from available choices

2081: ChoiceField, MultipleChoiceField
2082: FilePathField
2083: ManyRelatedField

Field is empty

2091: FileField, ImageField
2092: MultipleChoiceField
2093: ManyRelatedField

File has no name

2101: FileField, ImageField

File is an invalid image

2111: ImageField

Field is not a list

2121: MultipleChoiceField
2122: ListField
2123: ManyRelatedField

Field is not a dict

2131: DictField

Field is not a json

2141: JSONField

Field does not exist (invalid hyperlink, primary key, etc.)

2151: PrimaryKeyRelatedField, HyperlinkedRelatedField, SlugRelatedField, HyperlinkedIdentityField

Incorrect type for relation key

2161: PrimaryKeyRelatedField, HyperlinkedRelatedField, SlugRelatedField, HyperlinkedIdentityField

Couldn't match url or name to a view

2171: HyperlinkedRelatedField, HyperlinkedIdentityField

Expected a DateTime, got Date

2181: DateTimeField

Excpected a Date, got DateTime

2191: DateField

Too many digits for defined Decimal

2201: DecimalField

Too many whole digits for defined Decimal

2211: DecimalField

Too many decimal digits for defined Decimal

2221: DecimalField

Default built-in validators error codes

UniqueValidator: 3001
UniqueTogetherValidator: 3003
UniqueForDateValidator: 3004
UniqueForMonthValidator: 3004
UniqueForYearValidator: 3005
RegexValidator: 3006
EmailValidator: 3007
URLValidator: 3008
MaxValueValidator: 3009
MinValueValidator: 3010
MaxLengthValidator: 3011
MinLengthValidator: 3012
DecimalValidator: 3013
validate_email: 3014
validate_slug: 3015
validate_unicode_slug: 3016
validate_ipv4_address: 3017
validate_ipv46_address: 3018
validate_comma_separated_integer_list: 3019
int_list_validator: 3020

Other error codes not related to serializer validation

Server Error: 4000
Parser Error (exception was raised by Parser class): 4001,
Authentication Failed (invalid credentials were provided): 4002,
Not Authenticated (no credentials were provided): 4003,
Not Found: 4004,
Permission Denied: 4005,
Method Not Allowed (invalid HTTP method): 4006,
Not Acceptable (Could not satisfy the request Accept header): 4007,
Unsupported Media-Type: 4008,
Throttled (Too many requests): 4009

Tests

Pull requests won't be accepted without passing tests. You can run the test suite with:

python runtests.py

Contributors

toxinu

FutureMind/drf-friendly-errors

FutureMind

Reviews

Repository Details