Add implementation of schema for OData V4

- Enum types is working
- Complex type is working(including BaseType)
- Entity type needs editing

Author: mamiksik

.pylintrc

@@ -65,8 +65,10 @@ confidence=
 # --enable=similarities". If you want to run only the classes checker, but have
 # no Warning level messages displayed, use"--disable=all --enable=classes
 # --disable=W"
-disable=locally-disabled
+disable=locally-disabled,duplicate-code
 
+# As parts of definitions are the same even for different versions,
+# pylint detects them as duplicate code which it is not. Disabling pylint 'duplicate-code' inside module did not work.
 
 [REPORTS]
 

pyodata/model/elements.py

@@ -29,7 +29,7 @@ def from_etree(cls, etree, config: Config, **kwargs):
             raise PyODataParserError(f'{cls.__name__} is unsupported in {config.odata_version.__name__}')
 
         if kwargs:
-            return callback(etree, config, kwargs)
+            return callback(etree, config, **kwargs)
 
         return callback(etree, config)
 

pyodata/model/from_etree_callbacks.py

@@ -1,6 +1,7 @@
 """ Reusable implementation of from_etree methods for the most of edm elements """
 
 # pylint: disable=unused-argument, missing-docstring, invalid-name
+import copy
 import logging
 
 from pyodata.config import Config
@@ -40,12 +41,23 @@ def struct_type_property_from_etree(entity_type_property_node, config: Config):
 
 
 # pylint: disable=protected-access
-def struct_type_from_etree(type_node, config: Config, kwargs):
+def struct_type_from_etree(type_node, config: Config, typ, schema=None):
     name = type_node.get('Name')
-    label = sap_attribute_get_string(type_node, 'label')
-    is_value_list = sap_attribute_get_bool(type_node, 'value-list', False)
+    base_type = type_node.get('BaseType')
 
-    stype = kwargs['type'](name, label, is_value_list)
+    if base_type is None:
+        label = sap_attribute_get_string(type_node, 'label')
+        is_value_list = sap_attribute_get_bool(type_node, 'value-list', False)
+        stype = typ(name, label, is_value_list)
+    else:
+        base_type = Types.parse_type_name(base_type)
+
+        try:
+            stype = copy.deepcopy(schema.get_type(base_type))
+        except KeyError:
+            raise PyODataParserError(f'BaseType \'{base_type.name}\' not found in schema')
+
+        stype._name = name
 
     for proprty in type_node.xpath('edm:Property', namespaces=config.namespaces):
         stp = StructTypeProperty.from_etree(proprty, config)
@@ -59,23 +71,19 @@ def struct_type_from_etree(type_node, config: Config, kwargs):
     # all properites are loaded because
     # there might be links between them.
     for ctp in list(stype._properties.values()):
-        ctp.struct_type = stype
+        if ctp.struct_type is None:  # TODO: Is it correct
+            ctp.struct_type = stype
 
     return stype
 
 
-def navigation_type_property_from_etree(node, config: Config):
-    return NavigationTypeProperty(
-        node.get('Name'), node.get('FromRole'), node.get('ToRole'), Identifier.parse(node.get('Relationship')))
-
-
-def complex_type_from_etree(etree, config: Config):
-    return StructType.from_etree(etree, config, type=ComplexType)
+def complex_type_from_etree(etree, config: Config, schema=None):
+    return StructType.from_etree(etree, config, typ=ComplexType, schema=schema)
 
 
 # pylint: disable=protected-access
-def entity_type_from_etree(etree, config: Config):
-    etype = StructType.from_etree(etree, config, type=EntityType)
+def entity_type_from_etree(etree, config: Config, schema=None):
+    etype = StructType.from_etree(etree, config, typ=EntityType, schema=schema)
 
     for proprty in etree.xpath('edm:Key/edm:PropertyRef', namespaces=config.namespaces):
         etype._key.append(etype.proprty(proprty.get('Name')))
@@ -92,14 +100,18 @@ def entity_type_from_etree(etree, config: Config):
 
 
 # pylint: disable=protected-access, too-many-locals
-def enum_type_from_etree(type_node, config: Config, kwargs):
+def enum_type_from_etree(type_node, config: Config, namespace):
     ename = type_node.get('Name')
     is_flags = type_node.get('IsFlags')
 
-    namespace = kwargs['namespace']
+    # namespace = kwargs['namespace']
 
     underlying_type = type_node.get('UnderlyingType')
 
+    # https://docs.oasis-open.org/odata/odata-csdl-json/v4.01/csprd04/odata-csdl-json-v4.01-csprd04.html#sec_EnumerationType
+    if underlying_type is None:
+        underlying_type = 'Edm.Int32'
+
     valid_types = {
         'Edm.Byte': [0, 2 ** 8 - 1],
         'Edm.Int16': [-2 ** 15, 2 ** 15 - 1],
@@ -263,8 +275,7 @@ def external_annotation_from_etree(annotations_node, config):
         yield annot
 
 
-def annotation_from_etree(target, config, kwargs):
-    annotation_node = kwargs['annotation_node']
+def annotation_from_etree(target, config, annotation_node):
     term = annotation_node.get('Term')
 
     if term in config.sap_annotation_value_list:
@@ -274,13 +285,12 @@ def annotation_from_etree(target, config, kwargs):
     return None
 
 
-def value_helper_from_etree(target, config, kwargs):
+def value_helper_from_etree(target, config, annotation_node):
     label = None
     collection_path = None
     search_supported = False
     params_node = None
 
-    annotation_node = kwargs['annotation_node']
     for prop_value in annotation_node.xpath('edm:Record/edm:PropertyValue', namespaces=config.annotation_namespace):
         rprop = prop_value.get('Property')
         if rprop == 'Label':

pyodata/v2/__init__.py

@@ -18,10 +18,13 @@
     NullAssociation
 
 from pyodata.model.from_etree_callbacks import struct_type_property_from_etree, struct_type_from_etree, \
-    navigation_type_property_from_etree, complex_type_from_etree, entity_type_from_etree, enum_type_from_etree, \
-    entity_set_from_etree, end_role_from_etree, referential_constraint_from_etree, association_from_etree, \
-    association_set_end_role_from_etree, association_set_from_etree, external_annotation_from_etree, \
-    annotation_from_etree, value_helper_from_etree, value_helper_parameter_from_etree, function_import_from_etree
+    entity_type_from_etree, enum_type_from_etree, entity_set_from_etree, end_role_from_etree, \
+    referential_constraint_from_etree, association_from_etree, association_set_end_role_from_etree, \
+    association_set_from_etree, external_annotation_from_etree, annotation_from_etree, value_helper_from_etree, \
+    value_helper_parameter_from_etree, function_import_from_etree, complex_type_from_etree
+
+
+from pyodata.v2.from_etree_callbacks import navigation_type_property_from_etree
 
 
 def modlog():

pyodata/v2/from_etree_callbacks.py

@@ -0,0 +1,9 @@
+# pylint: disable=missing-docstring,invalid-name,unused-argument
+
+from pyodata.model.elements import NavigationTypeProperty, Identifier
+from pyodata.config import Config
+
+
+def navigation_type_property_from_etree(node, config: Config):
+    return NavigationTypeProperty(
+        node.get('Name'), node.get('FromRole'), node.get('ToRole'), Identifier.parse(node.get('Relationship')))

pyodata/v4/__init__.py

@@ -2,19 +2,29 @@
 
 from typing import List
 
+from pyodata.model.from_etree_callbacks import enum_type_from_etree, struct_type_property_from_etree, \
+    struct_type_from_etree, complex_type_from_etree
 from pyodata.config import ODATAVersion
 from pyodata.model.type_traits import EdmBooleanTypTraits, EdmIntTypTraits
-from pyodata.model.elements import Typ
+from pyodata.model.elements import Typ, Schema, EnumType, ComplexType, StructType, StructTypeProperty
 from pyodata.v4.type_traits import EdmDateTypTraits, GeoTypeTraits, EdmDoubleQuotesEncapsulatedTypTraits, \
     EdmTimeOfDay, EdmDateTimeOffsetTypTraits, EdmDuration
 
+from pyodata.v4.from_etree_callbacks import schema_from_etree
+
 
 class ODataV4(ODATAVersion):
     """ Definition of OData V4 """
 
     @staticmethod
     def from_etree_callbacks():
         return {
+            StructTypeProperty: struct_type_property_from_etree,
+            StructType: struct_type_from_etree,
+            # NavigationTypeProperty: navigation_type_property_from_etree,
+            EnumType: enum_type_from_etree,
+            ComplexType: complex_type_from_etree,
+            Schema: schema_from_etree,
         }
 
     @staticmethod

pyodata/v4/from_etree_callbacks.py

@@ -0,0 +1,46 @@
+# pylint: disable=missing-docstring,invalid-name,unused-argument,protected-access
+from pyodata.config import Config
+from pyodata.exceptions import PyODataParserError
+from pyodata.model.elements import ComplexType, Schema, EnumType, NullType
+from pyodata.policies import ParserError
+
+
+def schema_from_etree(schema_nodes, config: Config):
+    schema = Schema(config)
+
+    # Parse Schema nodes by parts to get over the problem of not-yet known
+    # entity types referenced by entity sets, function imports and
+    # annotations.
+
+    # TODO: First, process EnumType, EntityType and ComplexType nodes.
+    #  They have almost no dependencies on other elements.
+    for schema_node in schema_nodes:
+        namespace = schema_node.get('Namespace')
+        decl = Schema.Declaration(namespace)
+        schema._decls[namespace] = decl
+
+        for enum_type in schema_node.xpath('edm:EnumType', namespaces=config.namespaces):
+            try:
+                etype = EnumType.from_etree(enum_type, config, namespace=namespace)
+            except (PyODataParserError, AttributeError) as ex:
+                config.err_policy(ParserError.ENUM_TYPE).resolve(ex)
+                etype = NullType(enum_type.get('Name'))
+
+            decl.add_enum_type(etype)
+
+        for complex_type in schema_node.xpath('edm:ComplexType', namespaces=config.namespaces):
+            try:
+                ctype = ComplexType.from_etree(complex_type, config, schema=schema)
+            except (KeyError, AttributeError) as ex:
+                config.err_policy(ParserError.COMPLEX_TYPE).resolve(ex)
+                ctype = NullType(complex_type.get('Name'))
+
+            decl.add_complex_type(ctype)
+
+    # TODO: resolve types of properties
+    # TODO: Then, process Associations nodes because they refer EntityTypes and they are referenced by AssociationSets.
+    # TODO: resolve navigation properties
+    # TODO: Then, process EntitySet, FunctionImport and AssociationSet nodes.
+    # TODO: Finally, process Annotation nodes when all Scheme nodes are completely processed.
+
+    return Schema

tests/conftest.py

@@ -6,11 +6,20 @@
 
 
 @pytest.fixture
-def metadata():
+def metadata_v2():
+    return metadata('metadata.xml')
+
+
+@pytest.fixture
+def metadata_v4():
+    return metadata('metadata_v4.xml')
+
+
+def metadata(file_name: str):
     """Example OData metadata"""
     path_to_current_file = os.path.realpath(__file__)
     current_directory = os.path.split(path_to_current_file)[0]
-    path_to_file = os.path.join(current_directory, "metadata.xml")
+    path_to_file = os.path.join(current_directory, file_name)
 
     return open(path_to_file, 'rb').read()
 
@@ -107,12 +116,12 @@ def _data_services_epilogue(self):
 
 
 @pytest.fixture
-def schema(metadata):
+def schema(metadata_v2):
     """Parsed metadata"""
 
     # pylint: disable=redefined-outer-name
 
-    return schema_from_xml(metadata)
+    return schema_from_xml(metadata_v2)
 
 
 def assert_logging_policy(mock_warning, *args):