add

ccxt/static_dependencies/marshmallow_oneofschema/__init__.py

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+from .one_of_schema import OneOfSchema  # noqa

ccxt/static_dependencies/marshmallow_oneofschema/one_of_schema.py

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+import typing
+
+from ..marshmallow import Schema, ValidationError
+
+
+class OneOfSchema(Schema):
+    """
+    This is a special kind of schema that actually multiplexes other schemas
+    based on object type. When serializing values, it uses get_obj_type() method
+    to get object type name. Then it uses `type_schemas` name-to-Schema mapping
+    to get schema for that particular object type, serializes object using that
+    schema and adds an extra "type" field with name of object type.
+    Deserialization is reverse.
+
+    Example:
+
+        class Foo(object):
+            def __init__(self, foo):
+                self.foo = foo
+
+        class Bar(object):
+            def __init__(self, bar):
+                self.bar = bar
+
+        class FooSchema(marshmallow.Schema):
+            foo = marshmallow.fields.String(required=True)
+
+            @marshmallow.post_load
+            def make_foo(self, data, **kwargs):
+                return Foo(**data)
+
+        class BarSchema(marshmallow.Schema):
+            bar = marshmallow.fields.Integer(required=True)
+
+            @marshmallow.post_load
+            def make_bar(self, data, **kwargs):
+                return Bar(**data)
+
+        class MyUberSchema(marshmallow.OneOfSchema):
+            type_schemas = {
+                'foo': FooSchema,
+                'bar': BarSchema,
+            }
+
+            def get_obj_type(self, obj):
+                if isinstance(obj, Foo):
+                    return 'foo'
+                elif isinstance(obj, Bar):
+                    return 'bar'
+                else:
+                    raise Exception('Unknown object type: %s' % repr(obj))
+
+        MyUberSchema().dump([Foo(foo='hello'), Bar(bar=123)], many=True)
+        # => [{'type': 'foo', 'foo': 'hello'}, {'type': 'bar', 'bar': 123}]
+
+    You can control type field name added to serialized object representation by
+    setting `type_field` class property.
+    """
+
+    type_field = "type"
+    type_field_remove = True
+    type_schemas: typing.Mapping[str, typing.Union[typing.Type[Schema], Schema]] = {}
+
+    def get_obj_type(self, obj):
+        """Returns name of the schema during dump() calls, given the object
+        being dumped."""
+        return obj.__class__.__name__
+
+    def get_data_type(self, data):
+        """Returns name of the schema during load() calls, given the data being
+        loaded. Defaults to looking up `type_field` in the data."""
+        data_type = data.get(self.type_field)
+        if self.type_field in data and self.type_field_remove:
+            data.pop(self.type_field)
+        return data_type
+
+    def dump(self, obj, *, many=None, **kwargs):
+        errors = {}
+        result_data = []
+        result_errors = {}
+        many = self.many if many is None else bool(many)
+        if not many:
+            result = result_data = self._dump(obj, **kwargs)
+        else:
+            for idx, o in enumerate(obj):
+                try:
+                    result = self._dump(o, **kwargs)
+                    result_data.append(result)
+                except ValidationError as error:
+                    result_errors[idx] = error.normalized_messages()
+                    result_data.append(error.valid_data)
+
+        result = result_data
+        errors = result_errors
+
+        if not errors:
+            return result
+        else:
+            exc = ValidationError(errors, data=obj, valid_data=result)
+            raise exc
+
+    def _dump(self, obj, *, update_fields=True, **kwargs):
+        obj_type = self.get_obj_type(obj)
+        if obj_type is None:
+            return (
+                None,
+                {"_schema": f"Unknown object class: {obj.__class__.__name__}"},
+            )
+
+        type_schema = self.type_schemas.get(obj_type)
+        if not type_schema:
+            return None, {"_schema": f"Unsupported object type: {obj_type}"}
+
+        schema = type_schema if isinstance(type_schema, Schema) else type_schema()
+
+        schema.context.update(getattr(self, "context", {}))
+
+        result = schema.dump(obj, many=False, **kwargs)
+        if result is not None:
+            result[self.type_field] = obj_type
+        return result
+
+    def load(self, data, *, many=None, partial=None, unknown=None, **kwargs):
+        errors = {}
+        result_data = []
+        result_errors = {}
+        many = self.many if many is None else bool(many)
+        if partial is None:
+            partial = self.partial
+        if not many:
+            try:
+                result = result_data = self._load(
+                    data, partial=partial, unknown=unknown, **kwargs
+                )
+                #  result_data.append(result)
+            except ValidationError as error:
+                result_errors = error.normalized_messages()
+                result_data.append(error.valid_data)
+        else:
+            for idx, item in enumerate(data):
+                try:
+                    result = self._load(item, partial=partial, **kwargs)
+                    result_data.append(result)
+                except ValidationError as error:
+                    result_errors[idx] = error.normalized_messages()
+                    result_data.append(error.valid_data)
+
+        result = result_data
+        errors = result_errors
+
+        if not errors:
+            return result
+        else:
+            exc = ValidationError(errors, data=data, valid_data=result)
+            raise exc
+
+    def _load(self, data, *, partial=None, unknown=None, **kwargs):
+        if not isinstance(data, dict):
+            raise ValidationError({"_schema": f"Invalid data type: {data}"})
+
+        data = dict(data)
+        unknown = unknown or self.unknown
+        data_type = self.get_data_type(data)
+
+        if data_type is None:
+            raise ValidationError(
+                {self.type_field: ["Missing data for required field."]}
+            )
+
+        try:
+            type_schema = self.type_schemas.get(data_type)
+        except TypeError as error:
+            # data_type could be unhashable
+            raise ValidationError(
+                {self.type_field: [f"Invalid value: {data_type}"]}
+            ) from error
+        if not type_schema:
+            raise ValidationError(
+                {self.type_field: [f"Unsupported value: {data_type}"]}
+            )
+
+        schema = type_schema if isinstance(type_schema, Schema) else type_schema()
+
+        schema.context.update(getattr(self, "context", {}))
+
+        return schema.load(data, many=False, partial=partial, unknown=unknown, **kwargs)
+
+    def validate(self, data, *, many=None, partial=None):
+        try:
+            self.load(data, many=many, partial=partial)
+        except ValidationError as ve:
+            return ve.messages
+        return {}