diff --git a/requirements/requirements-testing.txt b/requirements/requirements-testing.txt index a2a2fa7532..5799291ef2 100644 --- a/requirements/requirements-testing.txt +++ b/requirements/requirements-testing.txt @@ -2,3 +2,4 @@ pytest==4.3.0 pytest-django==3.4.8 pytest-cov==2.6.1 +mock==3.0.5; python_version < '3.0' diff --git a/rest_framework/compat.py b/rest_framework/compat.py index d61ca5dbba..506d1356c7 100644 --- a/rest_framework/compat.py +++ b/rest_framework/compat.py @@ -8,7 +8,6 @@ import sys from django.conf import settings -from django.core import validators from django.utils import six from django.views.generic import View @@ -299,34 +298,5 @@ def md_filter_add_syntax_highlight(md): INDENT_SEPARATORS = (b',', b': ') -class CustomValidatorMessage(object): - """ - We need to avoid evaluation of `lazy` translated `message` in `django.core.validators.BaseValidator.__init__`. - https://github.com/django/django/blob/75ed5900321d170debef4ac452b8b3cf8a1c2384/django/core/validators.py#L297 - - Ref: https://github.com/encode/django-rest-framework/pull/5452 - """ - - def __init__(self, *args, **kwargs): - self.message = kwargs.pop('message', self.message) - super(CustomValidatorMessage, self).__init__(*args, **kwargs) - - -class MinValueValidator(CustomValidatorMessage, validators.MinValueValidator): - pass - - -class MaxValueValidator(CustomValidatorMessage, validators.MaxValueValidator): - pass - - -class MinLengthValidator(CustomValidatorMessage, validators.MinLengthValidator): - pass - - -class MaxLengthValidator(CustomValidatorMessage, validators.MaxLengthValidator): - pass - - # Version Constants. PY36 = sys.version_info >= (3, 6) diff --git a/rest_framework/fields.py b/rest_framework/fields.py index c8f65db0e5..47829e5079 100644 --- a/rest_framework/fields.py +++ b/rest_framework/fields.py @@ -13,7 +13,8 @@ from django.core.exceptions import ObjectDoesNotExist from django.core.exceptions import ValidationError as DjangoValidationError from django.core.validators import ( - EmailValidator, RegexValidator, URLValidator, ip_address_validators + EmailValidator, MaxLengthValidator, MaxValueValidator, MinLengthValidator, + MinValueValidator, RegexValidator, URLValidator, ip_address_validators ) from django.forms import FilePathField as DjangoFilePathField from django.forms import ImageField as DjangoImageField @@ -24,7 +25,6 @@ from django.utils.duration import duration_string from django.utils.encoding import is_protected_type, smart_text from django.utils.formats import localize_input, sanitize_separators -from django.utils.functional import lazy from django.utils.ipv6 import clean_ipv6_address from django.utils.timezone import utc from django.utils.translation import ugettext_lazy as _ @@ -32,13 +32,12 @@ from rest_framework import ISO_8601 from rest_framework.compat import ( - Mapping, MaxLengthValidator, MaxValueValidator, MinLengthValidator, - MinValueValidator, ProhibitNullCharactersValidator, unicode_repr, - unicode_to_repr + Mapping, ProhibitNullCharactersValidator, unicode_repr, unicode_to_repr ) from rest_framework.exceptions import ErrorDetail, ValidationError from rest_framework.settings import api_settings from rest_framework.utils import html, humanize_datetime, json, representation +from rest_framework.utils.formatting import lazy_format class empty: @@ -766,15 +765,11 @@ def __init__(self, **kwargs): self.min_length = kwargs.pop('min_length', None) super(CharField, self).__init__(**kwargs) if self.max_length is not None: - message = lazy( - self.error_messages['max_length'].format, - six.text_type)(max_length=self.max_length) + message = lazy_format(self.error_messages['max_length'], max_length=self.max_length) self.validators.append( MaxLengthValidator(self.max_length, message=message)) if self.min_length is not None: - message = lazy( - self.error_messages['min_length'].format, - six.text_type)(min_length=self.min_length) + message = lazy_format(self.error_messages['min_length'], min_length=self.min_length) self.validators.append( MinLengthValidator(self.min_length, message=message)) @@ -935,15 +930,11 @@ def __init__(self, **kwargs): self.min_value = kwargs.pop('min_value', None) super(IntegerField, self).__init__(**kwargs) if self.max_value is not None: - message = lazy( - self.error_messages['max_value'].format, - six.text_type)(max_value=self.max_value) + message = lazy_format(self.error_messages['max_value'], max_value=self.max_value) self.validators.append( MaxValueValidator(self.max_value, message=message)) if self.min_value is not None: - message = lazy( - self.error_messages['min_value'].format, - six.text_type)(min_value=self.min_value) + message = lazy_format(self.error_messages['min_value'], min_value=self.min_value) self.validators.append( MinValueValidator(self.min_value, message=message)) @@ -975,15 +966,11 @@ def __init__(self, **kwargs): self.min_value = kwargs.pop('min_value', None) super(FloatField, self).__init__(**kwargs) if self.max_value is not None: - message = lazy( - self.error_messages['max_value'].format, - six.text_type)(max_value=self.max_value) + message = lazy_format(self.error_messages['max_value'], max_value=self.max_value) self.validators.append( MaxValueValidator(self.max_value, message=message)) if self.min_value is not None: - message = lazy( - self.error_messages['min_value'].format, - six.text_type)(min_value=self.min_value) + message = lazy_format(self.error_messages['min_value'], min_value=self.min_value) self.validators.append( MinValueValidator(self.min_value, message=message)) @@ -1034,15 +1021,11 @@ def __init__(self, max_digits, decimal_places, coerce_to_string=None, max_value= super(DecimalField, self).__init__(**kwargs) if self.max_value is not None: - message = lazy( - self.error_messages['max_value'].format, - six.text_type)(max_value=self.max_value) + message = lazy_format(self.error_messages['max_value'], max_value=self.max_value) self.validators.append( MaxValueValidator(self.max_value, message=message)) if self.min_value is not None: - message = lazy( - self.error_messages['min_value'].format, - six.text_type)(min_value=self.min_value) + message = lazy_format(self.error_messages['min_value'], min_value=self.min_value) self.validators.append( MinValueValidator(self.min_value, message=message)) @@ -1380,15 +1363,11 @@ def __init__(self, **kwargs): self.min_value = kwargs.pop('min_value', None) super(DurationField, self).__init__(**kwargs) if self.max_value is not None: - message = lazy( - self.error_messages['max_value'].format, - six.text_type)(max_value=self.max_value) + message = lazy_format(self.error_messages['max_value'], max_value=self.max_value) self.validators.append( MaxValueValidator(self.max_value, message=message)) if self.min_value is not None: - message = lazy( - self.error_messages['min_value'].format, - six.text_type)(min_value=self.min_value) + message = lazy_format(self.error_messages['min_value'], min_value=self.min_value) self.validators.append( MinValueValidator(self.min_value, message=message)) @@ -1633,10 +1612,10 @@ def __init__(self, *args, **kwargs): super(ListField, self).__init__(*args, **kwargs) self.child.bind(field_name='', parent=self) if self.max_length is not None: - message = self.error_messages['max_length'].format(max_length=self.max_length) + message = lazy_format(self.error_messages['max_length'], max_length=self.max_length) self.validators.append(MaxLengthValidator(self.max_length, message=message)) if self.min_length is not None: - message = self.error_messages['min_length'].format(min_length=self.min_length) + message = lazy_format(self.error_messages['min_length'], min_length=self.min_length) self.validators.append(MinLengthValidator(self.min_length, message=message)) def get_value(self, dictionary): @@ -1907,9 +1886,7 @@ def __init__(self, model_field, **kwargs): max_length = kwargs.pop('max_length', None) super(ModelField, self).__init__(**kwargs) if max_length is not None: - message = lazy( - self.error_messages['max_length'].format, - six.text_type)(max_length=self.max_length) + message = lazy_format(self.error_messages['max_length'], max_length=self.max_length) self.validators.append( MaxLengthValidator(self.max_length, message=message)) diff --git a/rest_framework/utils/formatting.py b/rest_framework/utils/formatting.py index aa805f14e3..2f555bb446 100644 --- a/rest_framework/utils/formatting.py +++ b/rest_framework/utils/formatting.py @@ -5,7 +5,8 @@ import re -from django.utils.encoding import force_text +from django.utils import six +from django.utils.encoding import force_text, python_2_unicode_compatible from django.utils.html import escape from django.utils.safestring import mark_safe @@ -67,3 +68,30 @@ def markup_description(description): description = escape(description).replace('\n', '
') description = '

' + description + '

' return mark_safe(description) + + +@python_2_unicode_compatible +class lazy_format(object): + """ + Delay formatting until it's actually needed. + + Useful when the format string or one of the arguments is lazy. + + Not using Django's lazy because it is too slow. + """ + __slots__ = ('format_string', 'args', 'kwargs', 'result') + + def __init__(self, format_string, *args, **kwargs): + self.result = None + self.format_string = format_string + self.args = args + self.kwargs = kwargs + + def __str__(self): + if self.result is None: + self.result = self.format_string.format(*self.args, **self.kwargs) + self.format_string, self.args, self.kwargs = None, None, None + return self.result + + def __mod__(self, value): + return six.text_type(self) % value diff --git a/tests/test_utils.py b/tests/test_utils.py index 28b06b1735..c8c4d6f75d 100644 --- a/tests/test_utils.py +++ b/tests/test_utils.py @@ -1,6 +1,11 @@ # -*- coding: utf-8 -*- from __future__ import unicode_literals +try: + from unittest import mock +except ImportError: + import mock + from django.conf.urls import url from django.test import TestCase, override_settings @@ -9,6 +14,7 @@ from rest_framework.serializers import ModelSerializer from rest_framework.utils import json from rest_framework.utils.breadcrumbs import get_breadcrumbs +from rest_framework.utils.formatting import lazy_format from rest_framework.utils.urls import remove_query_param, replace_query_param from rest_framework.views import APIView from rest_framework.viewsets import ModelViewSet @@ -260,3 +266,19 @@ def test_invalid_unicode(self): removed_key = 'page' assert key in remove_query_param(q, removed_key) + + +class LazyFormatTests(TestCase): + def test_it_formats_correctly(self): + formatted = lazy_format('Does {} work? {answer}: %s', 'it', answer='Yes') + assert str(formatted) == 'Does it work? Yes: %s' + assert formatted % 'it does' == 'Does it work? Yes: it does' + + def test_it_formats_lazily(self): + message = mock.Mock(wraps='message') + formatted = lazy_format(message) + assert message.format.call_count == 0 + str(formatted) + assert message.format.call_count == 1 + str(formatted) + assert message.format.call_count == 1