Add localize keyword argument to `DecimalField` (#4233)

Add `localize` keyword argument for DecimalField

docs/api-guide/fields.md

@@ -261,9 +261,10 @@ Corresponds to `django.db.models.fields.DecimalField`.
 
 - `max_digits` The maximum number of digits allowed in the number. Note that this number must be greater than or equal to decimal_places.
 - `decimal_places` The number of decimal places to store with the number.
-- `coerce_to_string` Set to `True` if string values should be returned for the representation, or `False` if `Decimal` objects should be returned. Defaults to the same value as the `COERCE_DECIMAL_TO_STRING` settings key, which will be `True` unless overridden. If `Decimal` objects are returned by the serializer, then the final output format will be determined by the renderer.
+- `coerce_to_string` Set to `True` if string values should be returned for the representation, or `False` if `Decimal` objects should be returned. Defaults to the same value as the `COERCE_DECIMAL_TO_STRING` settings key, which will be `True` unless overridden. If `Decimal` objects are returned by the serializer, then the final output format will be determined by the renderer. Note that setting `localize` will force the value to `True`.
 - `max_value` Validate that the number provided is no greater than this value.
 - `min_value` Validate that the number provided is no less than this value.
+- `localize` Set to `True` to enable localization of input and output based on the current locale. This will also force `coerce_to_string` to `True`. Defaults to `False`. Note that data formatting is enabled if you have set `USE_L10N=True` in your settings file.
 
 #### Example usage
 

rest_framework/fields.py

@@ -25,6 +25,7 @@ from django.utils.dateparse import (
 )
 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 cached_property
 from django.utils.ipv6 import clean_ipv6_address
 from django.utils.translation import ugettext_lazy as _
@@ -871,6 +872,7 @@ class FloatField(Field):
             self.validators.append(MinValueValidator(self.min_value, message=message))
 
     def to_internal_value(self, data):
+
         if isinstance(data, six.text_type) and len(data) > self.MAX_STRING_LENGTH:
             self.fail('max_string_length')
 
@@ -895,11 +897,15 @@ class DecimalField(Field):
     }
     MAX_STRING_LENGTH = 1000  # Guard against malicious string inputs.
 
-    def __init__(self, max_digits, decimal_places, coerce_to_string=None, max_value=None, min_value=None, **kwargs):
+    def __init__(self, max_digits, decimal_places, coerce_to_string=None, max_value=None, min_value=None,
+                 localize=False, **kwargs):
         self.max_digits = max_digits
         self.decimal_places = decimal_places
+        self.localize = localize
         if coerce_to_string is not None:
             self.coerce_to_string = coerce_to_string
+        if self.localize:
+            self.coerce_to_string = True
 
         self.max_value = max_value
         self.min_value = min_value
@@ -923,7 +929,12 @@ class DecimalField(Field):
         Validate that the input is a decimal number and return a Decimal
         instance.
         """
+
         data = smart_text(data).strip()
+
+        if self.localize:
+            data = sanitize_separators(data)
+
         if len(data) > self.MAX_STRING_LENGTH:
             self.fail('max_string_length')
 
@@ -988,6 +999,9 @@ class DecimalField(Field):
 
         if not coerce_to_string:
             return quantized
+        if self.localize:
+            return localize_input(quantized)
+
         return '{0:f}'.format(quantized)
 
     def quantize(self, value):

tests/test_fields.py

@@ -5,6 +5,7 @@ from decimal import Decimal
 
 import pytest
 from django.http import QueryDict
+from django.test import TestCase, override_settings
 from django.utils import six, timezone
 
 import rest_framework
@@ -894,6 +895,22 @@ class TestNoStringCoercionDecimalField(FieldValues):
     )
 
 
+class TestLocalizedDecimalField(TestCase):
+    @override_settings(USE_L10N=True, LANGUAGE_CODE='pl')
+    def test_to_internal_value(self):
+        field = serializers.DecimalField(max_digits=2, decimal_places=1, localize=True)
+        self.assertEqual(field.to_internal_value('1,1'), Decimal('1.1'))
+
+    @override_settings(USE_L10N=True, LANGUAGE_CODE='pl')
+    def test_to_representation(self):
+        field = serializers.DecimalField(max_digits=2, decimal_places=1, localize=True)
+        self.assertEqual(field.to_representation(Decimal('1.1')), '1,1')
+
+    def test_localize_forces_coerce_to_string(self):
+        field = serializers.DecimalField(max_digits=2, decimal_places=1, coerce_to_string=False, localize=True)
+        self.assertTrue(isinstance(field.to_representation(Decimal('1.1')), six.string_types))
+
+
 class TestNoDecimalPlaces(FieldValues):
     valid_inputs = {
         '0.12345': Decimal('0.12345'),