Added ChoiceValidator (#5)

Author: nxexox

docs/api-guid/validators.md

@@ -138,6 +138,25 @@ This validator checks the string against a regular expression.
     validator = RegexValidator(r'\d+', True)
     validator('test')
 
+## ChoiceValidator
+
+This validator checks a value for an entry in a predefined list of values.
+
+**Signature**: `ChoiceValidator(choices, message=None)`
+
+- `choices` Valid values. Iter object. If `list`, `tuple`, `set` check into iter object. If `dict`, check key.
+- `message` The short message should fall out on validation error.
+
+**Example**:
+
+    validator = ChoiceValidator([1, 2, 3])
+    validator(2)
+
+    try:
+        validator(15)
+    except ValidationError:
+        pass
+
 ---
 
 # Writing custom validators

docs/release-notes.md

@@ -8,6 +8,12 @@ Medium version numbers (0.x.0) may include API changes, in line with the [deprec
 
 Major version numbers (x.0.0) are reserved for substantial project milestones.
 
+### 0.2.2
+
+**Date:** [15th Jule 2019]
+
+* Added [`ChoiceValidator`][ChoiceValidator] in [`serializers.validators`][Validators].
+
 ### 0.2.1
 
 **Date:** [22th May 2019]
@@ -90,4 +96,6 @@ Major version numbers (x.0.0) are reserved for substantial project milestones.
 [SerializerMethodField]: api-guid/fields.md#-serializermethodfield
 [InheritSerializers]: api-guid/serializers.md#serializer-inheritance
 [RegexValidator]: api-guid/validators.md#regexvalidator
+[ChoiceValidator]: api-guid/validators.md#choicevalidator
 [Serializers]: api-guid/serializers.md
+[Validators]: api-guid/validators.md

rest_framework/__init__.py

@@ -8,7 +8,7 @@
          __/ |
         |___/
 """
-VERSION = (0, 2, 1)
+VERSION = (0, 2, 2)
 
 __title__ = 'Python-Rest-Framework'
 __author__ = 'Deys Timofey'

rest_framework/serializers/validators.py

@@ -219,3 +219,35 @@ def __call__(self, value):
         """
         if not (self.inverse_match is not bool(self.regex.search(value))):
             raise ValidationError(self.message)
+
+
+class ChoiceValidator(BaseValidator):
+    """
+    Validator for validation choice field.
+
+    """
+    message = 'Value must be one of `{allowed_values}`.'
+
+    def __init__(self, choices, *args, **kwargs):
+        """
+        Validator for validation choice field.
+
+        :param Union[iter, dict] choices: Valid choices values.
+
+        """
+        try:
+            iter(choices)
+        except TypeError:
+            raise ValueError('`choices=` must be iter or dict. Reality: `{}`.'.format(type(choices)))
+        super().__init__(*args, **kwargs)
+        self.choices = choices
+
+    def __call__(self, value: object):
+        """
+        Validation.
+
+        :param object value: Object for validation.
+
+        """
+        if value not in self.choices:
+            raise ValidationError(self.message.format(**dict(allowed_values=self.choices)))

rest_framework/tests/test_validators.py

@@ -8,7 +8,7 @@
 
 from rest_framework.serializers.validators import (
     RegexValidator, BaseValidator, RequiredValidator, MinLengthValidator, MaxLengthValidator,
-    MinValueValidator, MaxValueValidator
+    MinValueValidator, MaxValueValidator, ChoiceValidator
 )
 from rest_framework.serializers.exceptions import ValidationError
 
@@ -172,3 +172,17 @@ class RegexValidatorTestCase(ValidatorTestCases):
         {'init': {'regex': r'\d+', 'message': 'test'}, 'data': 'test', 'message': 'test'},
         {'init': {'regex': r'\d+', 'inverse_match': True}, 'data': 'test'}
     )
+
+
+class ChoiceValidatorTestCase(ValidatorTestCases):
+    """
+    Testing ChoiceValidator.
+
+    """
+    validator_class = ChoiceValidator
+    cases = (
+        {'init': {'choices': [1, 2, 3]}, 'data': 3},
+        {'init': {'choices': {1: 1, 2: 2, 3: 3}}, 'data': 2},
+        {'init': {'choices': [1, 2, 3]}, 'data': 'asdasd', 'message': 'Value must be one of `[1, 2, 3]`.'},
+        {'init': {'choices': [1, 2, 3], 'message': 'test'}, 'data': 'test', 'message': 'test'},
+    )