Merge pull request #22 from dapper91/dev

- field default parameter support added.
- field default_factory parameter support added.
- root model validation added.
- pydantic field alias support implemented.

Author: dapper91

.pre-commit-config.yaml

@@ -38,7 +38,7 @@ repos:
           - commit
         args:
           - --diff
-  - repo: https://gitlab.com/pycqa/flake8
+  - repo: https://github.com/pycqa/flake8
     rev: 3.9.2
     hooks:
       - id: flake8

CHANGELOG.rst

@@ -1,6 +1,15 @@
 Changelog
 =========
 
+0.4.0 (2022-12-19)
+------------------
+
+- field default parameter support added.
+- field default_factory parameter support added.
+- root model validation added.
+- pydantic field alias support implemented.
+
+
 0.3.0 (2022-11-10)
 ------------------
 

README.md

@@ -356,7 +356,7 @@ AuthType = TypeVar('AuthType')
 PayloadType = TypeVar('PayloadType')
 
 
-class Request(pxml.BaseGenericXmlModel, Generic[AuthType, PayloadType], tag='reqeust'):
+class Request(pxml.BaseGenericXmlModel, Generic[AuthType, PayloadType], tag='request'):
     service_name: str = pxml.attr(name='service-name')
     request_id: str = pxml.attr(name='request-id')
     timestamp: dt.datetime = pxml.attr()

examples/generics.py

@@ -34,7 +34,7 @@ class BasicAuth(pxml.BaseXmlModel):
 PayloadType = TypeVar('PayloadType')
 
 
-class Request(pxml.BaseGenericXmlModel, Generic[AuthType, PayloadType], tag='reqeust'):
+class Request(pxml.BaseGenericXmlModel, Generic[AuthType, PayloadType], tag='request'):
     service_name: str = pxml.attr(name='service-name')
     request_id: str = pxml.attr(name='request-id')
     timestamp: dt.datetime = pxml.attr()

pydantic_xml/model.py

@@ -100,6 +100,11 @@ def __init__(
             nsmap: Optional[NsMap] = None,
             **kwargs: Any,
     ):
+        if entity is not None:
+            # copy arguments from the wrapped entity to let pydantic know how to process the field
+            for entity_field_name in entity.__slots__:
+                kwargs[entity_field_name] = getattr(entity, entity_field_name)
+
         super().__init__(**kwargs)
         self._entity = entity
         self._path = path
@@ -208,7 +213,7 @@ def __init_serializer__(cls) -> None:
         cls.__xml_serializer__ = serializers.ModelSerializerFactory.from_model(cls)
 
     @classmethod
-    def from_xml_tree(cls, root: etree.Element) -> 'BaseXmlModel':
+    def from_xml_tree(cls, root: etree.Element) -> Optional['BaseXmlModel']:
         """
         Deserializes an xml element tree to an object of `cls` type.
 
@@ -217,12 +222,15 @@ def from_xml_tree(cls, root: etree.Element) -> 'BaseXmlModel':
         """
 
         assert cls.__xml_serializer__ is not None, "model is partially initialized"
-        obj = cls.__xml_serializer__.deserialize(root)
 
-        return cls.parse_obj(obj)
+        if root.tag == cls.__xml_serializer__.element_name:
+            obj = cls.__xml_serializer__.deserialize(root)
+            return cls.parse_obj(obj)
+        else:
+            return None
 
     @classmethod
-    def from_xml(cls, source: Union[str, bytes]) -> 'BaseXmlModel':
+    def from_xml(cls, source: Union[str, bytes]) -> Optional['BaseXmlModel']:
         """
         Deserializes an xml string to an object of `cls` type.
 
@@ -248,7 +256,7 @@ def to_xml_tree(
 
         encoder = encoder or serializers.DEFAULT_ENCODER
 
-        assert self.__xml_serializer__ is not None
+        assert self.__xml_serializer__ is not None, "model is partially initialized"
         root = self.__xml_serializer__.serialize(None, self, encoder=encoder, skip_empty=skip_empty)
         assert root is not None
 
@@ -300,7 +308,7 @@ def __init_serializer__(cls) -> None:
             super().__init_serializer__()
 
     @classmethod
-    def from_xml_tree(cls, root: etree.Element) -> 'BaseXmlModel':
+    def from_xml_tree(cls, root: etree.Element) -> Optional['BaseXmlModel']:
         """
         Deserializes an xml element tree to an object of `cls` type.
 

pydantic_xml/serializers.py

@@ -200,7 +200,7 @@ class PrimitiveTypeSerializerFactory:
 
     class TextSerializer(Serializer):
         def serialize(
-                self,  element: etree.Element, value: Any, *, encoder: XmlEncoder, skip_empty: bool = False,
+                self, element: etree.Element, value: Any, *, encoder: XmlEncoder, skip_empty: bool = False,
         ) -> Optional[etree.Element]:
             if value is None and skip_empty:
                 return element
@@ -210,14 +210,14 @@ def serialize(
             return element
 
         def deserialize(self, element: etree.Element) -> Optional[str]:
-            return element.text
+            return element.text or None
 
     class AttributeSerializer(Serializer):
         def __init__(
                 self, model: Type['pxml.BaseXmlModel'], model_field: pd.fields.ModelField, ctx: Serializer.Context,
         ):
             ns_attrs = model.__xml_ns_attrs__
-            name = ctx.entity_name or model_field.name
+            name = ctx.entity_name or model_field.alias
             ns = ctx.entity_ns or (ctx.parent_ns if ns_attrs else None)
             nsmap = ctx.parent_nsmap
 
@@ -239,7 +239,7 @@ def deserialize(self, element: etree.Element) -> Optional[str]:
 
     class ElementSerializer(Serializer):
         def __init__(self, model_field: pd.fields.ModelField, ctx: Serializer.Context):
-            name = ctx.entity_name or model_field.name
+            name = ctx.entity_name or model_field.alias
             ns = ctx.entity_ns or ctx.parent_ns
             nsmap = merge_nsmaps(ctx.entity_nsmap, ctx.parent_nsmap)
             self.element_name = QName.from_alias(tag=name, ns=ns, nsmap=nsmap).uri
@@ -252,9 +252,7 @@ def serialize(
 
             encoded = encoder.encode(value)
 
-            if (sub_element := element.find(self.element_name)) is None:
-                sub_element = etree.SubElement(element, self.element_name)
-
+            sub_element = find_element_or_create(element, self.element_name)
             sub_element.text = encoded
             return sub_element
 
@@ -304,7 +302,7 @@ def __init__(
             self.is_root = is_root
             self.element_name = QName.from_alias(tag=name, ns=ns, nsmap=nsmap).uri
             self.field_serializers = {
-                field_name: self.build_field_serializer(model, model_subfield, ctx)
+                model_subfield.alias: self.build_field_serializer(model, model_subfield, ctx)
                 for field_name, model_subfield in model.__fields__.items()
             }
 
@@ -324,8 +322,9 @@ def serialize(
 
         def deserialize(self, element: etree.Element) -> Any:
             result = {
-                field_name: field_serializer.deserialize(element)
+                field_name: field_value
                 for field_name, field_serializer in self.field_serializers.items()
+                if (field_value := field_serializer.deserialize(element)) is not None
             }
             if self.is_root:
                 return result['__root__']
@@ -340,7 +339,7 @@ def __init__(
                 model: Type['pxml.BaseXmlModel'],
                 ctx: Serializer.Context,
         ):
-            field_name = model_field.name if model_field else None
+            field_name = model_field.alias if model_field else None
             name = ctx.entity_name or model.__xml_tag__ or field_name or model.__name__
             ns = ctx.entity_ns or model.__xml_ns__
             nsmap = merge_nsmaps(ctx.entity_nsmap, model.__xml_nsmap__, ctx.parent_nsmap)
@@ -433,7 +432,7 @@ class BaseSerializer(Serializer, abc.ABC):
         def __init__(
                 self, model: Type['pxml.BaseXmlModel'], model_field: pd.fields.ModelField, ctx: Serializer.Context,
         ):
-            name = ctx.entity_name or model_field.name
+            name = ctx.entity_name or model_field.alias
 
             self.parent_ns = ns = ctx.entity_ns or ctx.parent_ns
             self.parent_nsmap = nsmap = merge_nsmaps(ctx.entity_nsmap, ctx.parent_nsmap)
@@ -551,14 +550,14 @@ def __init__(
         ):
             assert model_field.sub_fields is not None, "unexpected model field"
 
-            name = ctx.entity_name or model_field.name
+            name = ctx.entity_name or model_field.alias
             ns = ctx.entity_ns or ctx.parent_ns
             nsmap = merge_nsmaps(ctx.entity_nsmap, ctx.parent_nsmap)
 
             self.element_name = QName.from_alias(tag=name, ns=ns, nsmap=nsmap).uri
 
             item_field = deepcopy(model_field.sub_fields[0])
-            item_field.name = model_field.name
+            item_field.name = model_field.alias
             self.serializer = self.build_field_serializer(
                 model,
                 item_field,
@@ -640,7 +639,7 @@ def __init__(
         ):
             assert model_field.sub_fields is not None, "unexpected model field"
 
-            name = ctx.entity_name or model_field.name
+            name = ctx.entity_name or model_field.alias
             ns = ctx.entity_ns or ctx.parent_ns
             nsmap = merge_nsmaps(ctx.entity_nsmap, ctx.parent_nsmap)
 
@@ -649,7 +648,7 @@ def __init__(
             self.serializers = []
             for sub_field in model_field.sub_fields:
                 sub_field = deepcopy(sub_field)
-                sub_field.name = model_field.name
+                sub_field.name = model_field.alias
 
                 self.serializers.append(
                     self.build_field_serializer(

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "pydantic-xml"
-version = "0.3.0"
+version = "0.4.0"
 description = "pydantic xml serialization/deserialization extension"
 authors = ["Dmitry Pershin <dapper1291@gmail.com>"]
 license = "Unlicense"

tests/test_misc.py

@@ -22,6 +22,15 @@ class TestModel(BaseXmlModel, tag='model'):
     assert_xml_equal(actual_xml, xml.encode())
 
 
+def test_root_model():
+    class TestModel(BaseXmlModel, tag='model'):
+        pass
+
+    xml = '''<model1/>'''
+
+    assert TestModel.from_xml(xml) is None
+
+
 def test_skip_empty():
     class TestSubModel(BaseXmlModel, tag='model'):
         text: Optional[str]
@@ -90,3 +99,43 @@ class TestModel(BaseXmlModel, tag='model'):
 
     actual_xml = obj.to_xml(skip_empty=True)
     assert_xml_equal(actual_xml, xml.encode())
+
+
+def test_defaults():
+    class TestModel(BaseXmlModel, tag='model'):
+        attr1: int = attr(default=1)
+        element1: int = element(default=1)
+        text: str = 'text'
+        attrs: Dict[str, str] = element(tag='model2', default={'key': 'value'})
+        element2: int = wrapped('wrapper', element(tag='model3', default=2))
+
+    xml = '<model/>'
+    actual_obj: TestModel = TestModel.from_xml(xml)
+    expected_obj: TestModel = TestModel()
+    assert actual_obj == expected_obj
+
+    expected_xml = '''
+        <model attr1="1">text<element1>1</element1><model2 key="value"/><wrapper><model3>2</model3></wrapper></model>
+    '''
+    actual_xml = actual_obj.to_xml(skip_empty=True)
+    assert_xml_equal(actual_xml, expected_xml.encode())
+
+
+def test_default_factory():
+    class TestModel(BaseXmlModel, tag='model'):
+        attr1: int = attr(default_factory=lambda: 1)
+        element1: int = element(default_factory=lambda: 1)
+        text: str = 'text'
+        attrs: Dict[str, str] = element(tag='model2', default_factory=lambda: {'key': 'value'})
+        element2: int = wrapped('wrapper', element(tag='model3', default_factory=lambda: 2))
+
+    xml = '<model/>'
+    actual_obj: TestModel = TestModel.from_xml(xml)
+    expected_obj: TestModel = TestModel()
+    assert actual_obj == expected_obj
+
+    expected_xml = '''
+        <model attr1="1">text<element1>1</element1><model2 key="value"/><wrapper><model3>2</model3></wrapper></model>
+    '''
+    actual_xml = actual_obj.to_xml(skip_empty=True)
+    assert_xml_equal(actual_xml, expected_xml.encode())

tests/test_submodels.py

@@ -13,7 +13,6 @@ class TestSubModel(BaseXmlModel, tag='model2'):
 
     class TestModel(BaseXmlModel, tag='model1'):
         model2: TestSubModel
-        model3: Optional[TestSubModel] = element(tag='model3')
 
     xml = '''
     <model1>
@@ -37,6 +36,24 @@ class TestModel(BaseXmlModel, tag='model1'):
     assert_xml_equal(actual_xml, xml)
 
 
+def test_optional_submodel_element_extraction():
+    class TestSubModel(BaseXmlModel, tag='model2'):
+        element1: float = element()
+
+    class TestModel(BaseXmlModel, tag='model1'):
+        model2: Optional[TestSubModel]
+
+    xml = '''<model1/>'''
+
+    actual_obj = TestModel.from_xml(xml)
+    expected_obj = TestModel(model2=None)
+
+    assert actual_obj == expected_obj
+
+    actual_xml = actual_obj.to_xml()
+    assert_xml_equal(actual_xml, xml)
+
+
 def test_root_submodel_element_extraction():
     class TestSubModel(BaseXmlModel, tag='model2'):
         __root__: int