Improve adherence to MLDCAT-AP specification (#148)

* Correct serialization of type_ and EndpointUrl to match definition

* Prefix all serialization aliases with object name to match JSON-LD

* Merge main into mldcat-ap

* Update numeric feature type reference

* Restore proper default port

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

src/schemas/datasets/mldcat_ap.py

@@ -34,7 +34,10 @@ class JsonLDObject(BaseModel, ABC):
     id_: str = Field(serialization_alias="@id")
     type_: str = Field(serialization_alias="@type")
 
-    model_config = {"populate_by_name": True, "extra": "forbid"}
+    model_config = {
+        "populate_by_name": True,
+        "extra": "forbid",
+    }
 
 
 T = TypeVar("T", bound=JsonLDObject)
@@ -66,8 +69,12 @@ class Agent(JsonLDObject):
     the use of the Organization Ontology is recommended.
     """
 
-    type_: Literal["Agent"] = "Agent"
-    name: list[JsonLiteral] = Field(default_factory=list, min_length=1)
+    type_: Literal["Agent"] = Field(default="Agent", serialization_alias="@type")
+    name: list[JsonLiteral] = Field(
+        default_factory=list,
+        min_length=1,
+        serialization_alias="Agent.name",
+    )
 
 
 class MD5Checksum(JsonLDObject):
@@ -76,11 +83,12 @@ class MD5Checksum(JsonLDObject):
     message digest algorithms to be represented.
     """
 
-    type_: Literal["Checksum"] = "Checksum"
-    algorithm: Literal[
-        "http://spdx.org/rdf/terms#checksumAlgorithm_md5"
-    ] = "http://spdx.org/rdf/terms#checksumAlgorithm_md5"
-    value: str = Field(serialization_alias="checksumValue")
+    type_: Literal["Checksum"] = Field(default="Checksum", serialization_alias="@type")
+    algorithm: Literal["http://spdx.org/rdf/terms#checksumAlgorithm_md5"] = Field(
+        "http://spdx.org/rdf/terms#checksumAlgorithm_md5",
+        serialization_alias="Checksum.algorithm",
+    )
+    value: str = Field(serialization_alias="Checksum.checksumValue")
 
 
 class FeatureType(StrEnum):
@@ -89,122 +97,168 @@ class FeatureType(StrEnum):
 
 
 class Feature(JsonLDObject):
-    type_: Literal["Feature"] = "Feature"
-    name: str = Field()
-    feature_type: FeatureType = Field(serialization_alias="type")
-    description: JsonLiteral | None = Field(default=None)
+    type_: Literal["Feature"] = Field(default="Feature", serialization_alias="@type")
+    name: str = Field(serialization_alias="Feature.name")
+    feature_type: str = Field(serialization_alias="Feature.type")
+    description: JsonLiteral | None = Field(default=None, serialization_alias="Feature.description")
 
 
 class QualityType(JsonLDObject):
-    type_: Literal["QualityType"] = "QualityType"
-    name: str = Field()
-    quality_id: str = Field(serialization_alias="id")
+    type_: Literal["QualityType"] = Field(default="QualityType", serialization_alias="@type")
+    name: str = Field(serialization_alias="QualityType.name")
+    quality_id: str = Field(serialization_alias="QualityType.id")
 
 
 class Quality(JsonLDObject):
-    type_: Literal["Quality"] = "Quality"
-    quality_type: QualityType = Field(serialization_alias="type")
-    value: JsonLiteral = Field()
+    type_: Literal["Quality"] = Field(default="Quality", serialization_alias="@type")
+    quality_type: QualityType = Field(serialization_alias="Quality.type")
+    value: JsonLiteral = Field(serialization_alias="Quality.value")
 
 
 class Distribution(JsonLDObject):
-    type_: Literal["Distribution"] = "Distribution"
+    type_: Literal["Distribution"] = Field(default="Distribution", serialization_alias="@type")
     # required
     access_url: list[HttpUrl] = Field(
         default_factory=list,
         min_length=1,
-        serialization_alias="accessUrl",
+        serialization_alias="Distribution.accessUrl",
     )
     has_feature: list[JsonLDObjectReference[Feature]] = Field(
         default_factory=list,
-        serialization_alias="hasFeature",
+        serialization_alias="Distribution.hasFeature",
         min_length=1,
     )
     has_quality: list[JsonLDObjectReference[Quality]] = Field(
         default_factory=list,
-        serialization_alias="hasQuality",
+        serialization_alias="Distribution.hasQuality",
         min_length=1,
     )
 
     # other
-    byte_size: JsonLiteral | None = Field(serialization_alias="byteSize", default=None)
+    byte_size: JsonLiteral | None = Field(serialization_alias="Distribution.byteSize", default=None)
     default_target_attribute: JsonLiteral | None = Field(
-        serialization_alias="defaultTargetAttribute",
+        serialization_alias="Distribution.defaultTargetAttribute",
+        default=None,
+    )
+    download_url: list[HttpUrl] = Field(
+        default_factory=list,
+        serialization_alias="Distribution.downloadUrl",
+    )
+    format_: JsonLiteral | None = Field(serialization_alias="Distribution.format", default=None)
+    identifier: JsonLiteral | None = Field(
         default=None,
+        serialization_alias="Distribution.identifier",
     )
-    download_url: list[HttpUrl] = Field(default_factory=list, serialization_alias="downloadUrl")
-    format_: JsonLiteral | None = Field(serialization_alias="format", default=None)
-    identifier: JsonLiteral | None = Field(default=None)
     ignore_attribute: list[JsonLiteral] = Field(
         default_factory=list,
-        serialization_alias="ignoreAttirbute",
+        serialization_alias="Distribution.ignoreAttribute",
     )
     processing_error: JsonLiteral | None = Field(
-        serialization_alias="processingError",
+        serialization_alias="Distribution.processingError",
         default=None,
     )
     processing_warning: JsonLiteral | None = Field(
-        serialization_alias="processingWarning",
+        serialization_alias="Distribution.processingWarning",
         default=None,
     )
-    processing_data: JsonLiteral | None = Field(serialization_alias="processingDate", default=None)
-    row_id_attribute: JsonLiteral | None = Field(serialization_alias="rowIDAttribute", default=None)
-    title: list[JsonLiteral] = Field(default_factory=list)
-    checksum: JsonLDObjectReference[MD5Checksum] | None = Field(default=None)
+    processing_data: JsonLiteral | None = Field(
+        serialization_alias="Distribution.processingDate",
+        default=None,
+    )
+    row_id_attribute: JsonLiteral | None = Field(
+        serialization_alias="Distribution.rowIDAttribute",
+        default=None,
+    )
+    title: list[JsonLiteral] = Field(default_factory=list, serialization_alias="Distribution.title")
+    checksum: JsonLDObjectReference[MD5Checksum] | None = Field(
+        default=None,
+        serialization_alias="Distribution.checksum",
+    )
 
     access_service: list[JsonLDObjectReference[DataService]] = Field(
         default_factory=list,
-        serialization_alias="accessService",
+        serialization_alias="Distribution.accessService",
     )
     # has_policy: Policy | None = Field(alias="hasPolicy")
     # language: list[LinguisticSystem] = Field(default_factory=list)
     # licence: LicenceDocument | None = Field()
 
 
 class Dataset(JsonLDObject):
-    type_: Literal["Dataset"] = "Dataset"
+    type_: Literal["Dataset"] = Field(default="Dataset", serialization_alias="@type")
     # required
-    collection_date: JsonLiteral = Field(serialization_alias="collectionDate")
-    description: list[JsonLiteral] = Field(default_factory=list, min_length=1)
-    title: list[JsonLiteral] = Field(default_factory=list, min_length=1)
+    collection_date: JsonLiteral = Field(serialization_alias="Dataset.collectionDate")
+    description: list[JsonLiteral] = Field(
+        default_factory=list,
+        min_length=1,
+        serialization_alias="Dataset.description",
+    )
+    title: list[JsonLiteral] = Field(
+        default_factory=list,
+        min_length=1,
+        serialization_alias="Dataset.title",
+    )
 
     # other
-    access_rights: AccessRights | None = Field(serialization_alias="accessRights", default=None)
-    contributor: list[JsonLDObjectReference[Agent]] = Field(default_factory=list)
-    creator: Agent | None = Field(default=None)
+    access_rights: AccessRights | None = Field(
+        serialization_alias="Dataset.accessRights",
+        default=None,
+    )
+    contributor: list[JsonLDObjectReference[Agent]] = Field(
+        default_factory=list,
+        serialization_alias="Dataset.contributor",
+    )
+    creator: Agent | None = Field(default=None, serialization_alias="Dataset.creator")
     distribution: list[JsonLDObjectReference[Distribution]] = Field(
         default_factory=list,
+        serialization_alias="Dataset.distribution",
     )
     has_version: list[JsonLDObjectReference[Dataset]] = Field(
         default_factory=list,
-        serialization_alias="hasVersion",
+        serialization_alias="Dataset.hasVersion",
     )
     identifier: list[JsonLiteral] = Field(default_factory=list)
     is_referenced_by: list[JsonLiteral] = Field(
         default_factory=list,
-        serialization_alias="isReferencedBy",
+        serialization_alias="Dataset.isReferencedBy",
     )
     is_version_of: list[JsonLDObjectReference[Dataset]] = Field(
         default_factory=list,
-        serialization_alias="isVersionOf",
+        serialization_alias="Dataset.isVersionOf",
+    )
+    issued: JsonLiteral | None = Field(default=None, serialization_alias="Dataset.issued")
+    keyword: list[JsonLiteral] = Field(default_factory=list, serialization_alias="Dataset.keyword")
+    landing_page: list[JsonLiteral] = Field(
+        default_factory=list,
+        serialization_alias="Dataset.landingPage",
     )
-    issued: JsonLiteral | None = Field(default=None)
-    keyword: list[JsonLiteral] = Field(default_factory=list)
-    landing_page: list[JsonLiteral] = Field(default_factory=list, serialization_alias="landingPage")
-    publisher: JsonLDObjectReference[Agent] | None = Field(default=None)
-    status: DatasetStatus | None = Field(default=None)
-    version_info: JsonLiteral | None = Field(serialization_alias="versionInfo", default=None)
-    version_label: JsonLiteral | None = Field(serialization_alias="versionLabel", default=None)
-    visibility: Visibility | None = Field(default=None)
+    publisher: JsonLDObjectReference[Agent] | None = Field(
+        default=None,
+        serialization_alias="Dataset.publisher",
+    )
+    status: DatasetStatus | None = Field(default=None, serialization_alias="Dataset.status")
+    version_info: JsonLiteral | None = Field(
+        serialization_alias="Dataset.versionInfo",
+        default=None,
+    )
+    version_label: JsonLiteral | None = Field(
+        serialization_alias="Dataset.versionLabel",
+        default=None,
+    )
+    visibility: Visibility | None = Field(default=None, serialization_alias="Dataset.visibility")
 
 
 class DataService(JsonLDObject):
-    type_: Literal["DataService"] = "DataService"
-    endpoint_url: HttpUrl = Field(serialization_alias="endpointUrl")
-    title: list[JsonLiteral] = Field(default_factory=list, min_length=1)
+    type_: Literal["DataService"] = Field(default="DataService", serialization_alias="@type")
+    endpoint_url: HttpUrl = Field(serialization_alias="DataService.endpointUrl")
+    title: list[JsonLiteral] = Field(
+        default_factory=list,
+        min_length=1,
+        serialization_alias="DataService.title",
+    )
     serves_dataset: list[JsonLDObjectReference[Dataset]] = Field(
         default_factory=list,
-        serialization_alias="servesDataset",
+        serialization_alias="DataService.servesDataset",
     )
 
 
@@ -232,7 +286,7 @@ def convert_to_mldcat_ap(dataset: DatasetMetadata) -> JsonLDGraph:
     example_feature = Feature(
         id_="example-petal-width",
         name="example_petal_width",
-        feature_type=FeatureType.NUMERIC,
+        feature_type="https://schema.org/Number",
         description="Feature information not loaded, this is an example.",
     )
 
@@ -252,7 +306,7 @@ def convert_to_mldcat_ap(dataset: DatasetMetadata) -> JsonLDGraph:
         access_url=[f"https://www.openml.org/d/{dataset.id_}"],
         has_feature=[JsonLDObjectReference[Feature].to(example_feature)],
         has_quality=[JsonLDObjectReference[Quality].to(example_quality)],
-        default_target_attribute=dataset.default_target_attribute,
+        default_target_attribute=next(iter(dataset.default_target_attribute), None),
         download_url=[dataset.url],
         format_=dataset.format_,
         checksum=JsonLDObjectReference[MD5Checksum].to(checksum),