Dict field allow empty (#6583)

* dict field: support allow_empty option

* document ListField allow_empty option

* document HStoreField allow_empty parameter
This commit is contained in:
gaetano-guerriero 2019-05-09 10:18:20 +02:00 committed by Tom Christie
parent 564faddb0f
commit a7c577cb31
3 changed files with 23 additions and 4 deletions

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@ -448,9 +448,10 @@ Requires either the `Pillow` package or `PIL` package. The `Pillow` package is
A field class that validates a list of objects.
**Signature**: `ListField(child=<A_FIELD_INSTANCE>, min_length=None, max_length=None)`
**Signature**: `ListField(child=<A_FIELD_INSTANCE>, allow_empty=True, min_length=None, max_length=None)`
- `child` - A field instance that should be used for validating the objects in the list. If this argument is not provided then objects in the list will not be validated.
- `allow_empty` - Designates if empty lists are allowed.
- `min_length` - Validates that the list contains no fewer than this number of elements.
- `max_length` - Validates that the list contains no more than this number of elements.
@ -471,9 +472,10 @@ We can now reuse our custom `StringListField` class throughout our application,
A field class that validates a dictionary of objects. The keys in `DictField` are always assumed to be string values.
**Signature**: `DictField(child=<A_FIELD_INSTANCE>)`
**Signature**: `DictField(child=<A_FIELD_INSTANCE>, allow_empty=True)`
- `child` - A field instance that should be used for validating the values in the dictionary. If this argument is not provided then values in the mapping will not be validated.
- `allow_empty` - Designates if empty dictionaries are allowed.
For example, to create a field that validates a mapping of strings to strings, you would write something like this:
@ -488,9 +490,10 @@ You can also use the declarative style, as with `ListField`. For example:
A preconfigured `DictField` that is compatible with Django's postgres `HStoreField`.
**Signature**: `HStoreField(child=<A_FIELD_INSTANCE>)`
**Signature**: `HStoreField(child=<A_FIELD_INSTANCE>, allow_empty=True)`
- `child` - A field instance that is used for validating the values in the dictionary. The default child field accepts both empty strings and null values.
- `allow_empty` - Designates if empty dictionaries are allowed.
Note that the child field **must** be an instance of `CharField`, as the hstore extension stores values as strings.

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@ -1663,11 +1663,13 @@ class DictField(Field):
child = _UnvalidatedField()
initial = {}
default_error_messages = {
'not_a_dict': _('Expected a dictionary of items but got type "{input_type}".')
'not_a_dict': _('Expected a dictionary of items but got type "{input_type}".'),
'empty': _('This dictionary may not be empty.'),
}
def __init__(self, *args, **kwargs):
self.child = kwargs.pop('child', copy.deepcopy(self.child))
self.allow_empty = kwargs.pop('allow_empty', True)
assert not inspect.isclass(self.child), '`child` has not been instantiated.'
assert self.child.source is None, (
@ -1693,6 +1695,9 @@ class DictField(Field):
data = html.parse_html_dict(data)
if not isinstance(data, dict):
self.fail('not_a_dict', input_type=type(data).__name__)
if not self.allow_empty and len(data) == 0:
self.fail('empty')
return self.run_child_validation(data)
def to_representation(self, value):

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@ -1982,6 +1982,7 @@ class TestDictField(FieldValues):
"""
valid_inputs = [
({'a': 1, 'b': '2', 3: 3}, {'a': '1', 'b': '2', '3': '3'}),
({}, {}),
]
invalid_inputs = [
({'a': 1, 'b': None, 'c': None}, {'b': ['This field may not be null.'], 'c': ['This field may not be null.']}),
@ -2009,6 +2010,16 @@ class TestDictField(FieldValues):
output = field.run_validation(None)
assert output is None
def test_allow_empty_disallowed(self):
"""
If allow_empty is False then an empty dict is not a valid input.
"""
field = serializers.DictField(allow_empty=False)
with pytest.raises(serializers.ValidationError) as exc_info:
field.run_validation({})
assert exc_info.value.detail == ['This dictionary may not be empty.']
class TestNestedDictField(FieldValues):
"""