Merge pull request #15 from Ultimaker/cs-452-foundation-for-native-types

Add toPlain method on fields [cs-452]

.gitignore

@@ -6,6 +6,7 @@
 
 # Packages
 *.egg
+*.eggs
 *.egg-info
 dist
 build

jsonmodels/fields.py

@@ -5,7 +5,7 @@
 import re
 import six
 from dateutil.parser import parse
-from typing import List, Optional, Dict, Set
+from typing import List, Optional, Dict, Set, Union, Pattern
 
 from .collections import ModelCollection
 from .errors import RequiredFieldError, BadTypeError, AmbiguousTypeError
@@ -14,6 +14,12 @@
 # it is a completely valid default value.
 NotSet = object()
 
+# BSON compatible types, which can be returned by toBsonEncodable.
+BsonEncodable = Union[
+ float, str, object, Dict, List, bytes, bool, datetime.datetime, None,
+ Pattern, int, bytes
+]
+
 
 class BaseField(object):
 
@@ -125,8 +131,26 @@ def _get_embed_type(value, models):
  return matching_models[0]
  return models[0]
 
+ def toBsonEncodable(self, value: types) -> BsonEncodable:
+ """Optionally return a bson encodable python object.
+
+ Returned object should be BSON compatible. By default uses the
+ `to_struct` method, which creates JSON compatible types. JSON is
+ compatible with bson, but only has support for limited types. When
+ required, this method should cast the value to supported bson type.
+ See: https://api.mongodb.com/python/current/api/bson/index.html
+
+ For example: when a value is a datetime object return it as a datetime
+ object. When a value is of CustomDateObject, cast it to a datetime
+ object before returning it.
+
+ :param value: Value
+ :return: a value which should be bson encodable
+ """
+ return self.to_struct(value=value)
+
  def to_struct(self, value):
- """Cast value to Python structure."""
+ """Cast value to Python dict."""
  return value
 
  def parse_value(self, value):

tests/test_plain.py

@@ -0,0 +1,11 @@
+from unittest import mock
+
+from jsonmodels import fields
+
+
+@mock.patch('jsonmodels.fields.BaseField.to_struct')
+def test_toBsonEncodable_calls_to_struct(f):
+ """Test if default implementation of toBsonEncodable calls to_struct."""
+ field = fields.StringField()
+ field.toBsonEncodable(value="text")
+ f.assert_called_once()