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ontocast.onto.ontology_header

Lightweight ontology catalog metadata read without materializing graphs.

OntologyHeader

Bases: OntologyPropertiesWithLineage

Ontology header metadata for a single stored named graph.

A header describes one version of an ontology (one named graph), carrying exactly the lineage fields terminal-version selection needs -- iri, hash, parent_hashes, created_at, version -- without the graph itself. This is deliberately not an :class:~ontocast.onto.ontology.Ontology: constructing one recomputes hash from the graph and defaults version, so a graph-less Ontology would carry fabricated lineage values.

Attributes:

Name Type Description
graph_uri str

Named graph URI holding this ontology version. May be the base ontology IRI or a versioned form (<iri>#<hash>).
Source code in ontocast/onto/ontology_header.py 
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class OntologyHeader(OntologyPropertiesWithLineage):
    """Ontology header metadata for a single stored named graph.

    A header describes one *version* of an ontology (one named graph), carrying
    exactly the lineage fields terminal-version selection needs -- ``iri``,
    ``hash``, ``parent_hashes``, ``created_at``, ``version`` -- without the graph
    itself. This is deliberately not an :class:`~ontocast.onto.ontology.Ontology`:
    constructing one recomputes ``hash`` from the graph and defaults ``version``,
    so a graph-less ``Ontology`` would carry fabricated lineage values.

    Attributes:
        graph_uri: Named graph URI holding this ontology version. May be the base
            ontology IRI or a versioned form (``<iri>#<hash>``).
    """

    graph_uri: str = Field(
        default="",
        description="Named graph URI holding this ontology version.",
    )

    @field_validator("version", mode="before")
    @classmethod
    def _coerce_version(cls, value: str | None) -> str | None:
        """Coerce stored ``owl:versionInfo`` text into a semantic version.

        Stored version info is arbitrary text (``"1.0"``, ``"3"``, ...), while
        ``Ontology`` normalizes it on construction. Mirror that here so header and
        ontology versions agree -- terminal selection tie-breaks on the value.
        """
        if value is None or not isinstance(value, str):
            return value
        return normalize_semantic_version(value)

    @classmethod
    def from_ontology(cls, ontology: Ontology) -> "OntologyHeader":
        """Build a header from a materialized ontology.

        Args:
            ontology: The ontology whose metadata should be captured.

        Returns:
            OntologyHeader: Header carrying the ontology's lineage metadata, with
            ``graph_uri`` set to the ontology's versioned IRI.
        """
        return cls(
            graph_uri=ontology.versioned_iri,
            iri=ontology.iri,
            ontology_id=ontology.ontology_id,
            title=ontology.title,
            description=ontology.description,
            version=ontology.version,
            hash=ontology.hash,
            parent_hashes=list(ontology.parent_hashes),
            created_at=ontology.created_at,
        )

from_ontology(ontology) classmethod

Build a header from a materialized ontology.

Parameters:

Name Type Description Default
ontology Ontology

The ontology whose metadata should be captured.

 required

Returns:

Name Type Description
OntologyHeader OntologyHeader

Header carrying the ontology's lineage metadata, with
OntologyHeader

graph_uri set to the ontology's versioned IRI.
Source code in ontocast/onto/ontology_header.py 
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@classmethod
def from_ontology(cls, ontology: Ontology) -> "OntologyHeader":
    """Build a header from a materialized ontology.

    Args:
        ontology: The ontology whose metadata should be captured.

    Returns:
        OntologyHeader: Header carrying the ontology's lineage metadata, with
        ``graph_uri`` set to the ontology's versioned IRI.
    """
    return cls(
        graph_uri=ontology.versioned_iri,
        iri=ontology.iri,
        ontology_id=ontology.ontology_id,
        title=ontology.title,
        description=ontology.description,
        version=ontology.version,
        hash=ontology.hash,
        parent_hashes=list(ontology.parent_hashes),
        created_at=ontology.created_at,
    )