Merge 42dca62e77 into 5bb02cc7b9

docs/api-guide/fields.md

@@ -364,6 +364,18 @@ As with `ChoiceField`, both the `allow_blank` and `allow_null` options are valid
 
 ---
 
+# Mapping field
+
+## MappingField
+
+A field that converts value with given mapping dict.
+
+    **Signature:** `MappingField(mapping)`
+
+- `mapping` - A dict of valid values that should be converted both directions.
+
+---
+
 # File upload fields
 
 #### Parsers and file uploads.

rest_framework/fields.py

@@ -1165,6 +1165,35 @@ class MultipleChoiceField(ChoiceField):
         ])
 
 
+# Mapping types...
+
+class MappingField(Field):
+    default_error_messages = {
+        'key_not_found': _('"{value}" not found in "mapping" keys'),
+        'value_not_found': _('"{value}" not found in "mapping" values')
+    }
+
+    def __init__(self, mapping, **kwargs):
+        super(MappingField, self).__init__(**kwargs)
+
+        assert isinstance(mapping, dict), '"mapping" should be a dictionary'
+        for k, v in mapping.items():
+            assert isinstance(k, (str, int)) and isinstance(v, (str, int)), '"mapping" can contain only str or int'
+
+        self.mapping = mapping
+        self.reverse_mapping = {v: k for k, v in mapping.iteritems()}
+
+    def to_representation(self, value):
+        if value in self.mapping:
+            return self.mapping[value]
+        self.fail('key_not_found', value=value)
+
+    def to_internal_value(self, data):
+        if data in self.reverse_mapping:
+            return self.reverse_mapping[data]
+        self.fail('value_not_found', value=data)
+
+
 # File types...
 
 class FileField(Field):

tests/test_fields.py

@@ -1125,6 +1125,38 @@ class TestMultipleChoiceField(FieldValues):
         assert field.get_value(QueryDict({})) == rest_framework.fields.empty
 
 
+# Mapping types...
+
+class TestMappingFieldWithIntKeys(FieldValues):
+    """
+    Valid and invalid values for `MappingField`.
+    """
+    valid_inputs = {
+        'one': 1,
+        'two': 2,
+        3: 'three',
+        4: 'four'
+    }
+    invalid_inputs = {
+        5: ['"5" not found in "mapping" values'],
+        'abc': ['"abc" not found in "mapping" values']
+    }
+    outputs = {
+        1: 'one',
+        2: 'two',
+        'three': 3,
+        'four': 4
+    }
+    field = serializers.MappingField(
+        mapping={
+            1: 'one',
+            2: 'two',
+            'three': 3,
+            'four': 4
+        }
+    )
+
+
 # File serializers...
 
 class MockFile: