Work with OSC metadata¶

These examples continue from the product Collection in the tutorial.

Update and clear fields¶

osc = OscExtension.ext(product)
osc.region = "Agulhas"
osc.experiment = None
assert "osc:experiment" not in product.extra_fields

ext() requires the OSC schema declaration. Pass add_if_missing=True to add it. Getters return None for absent fields, and assigning None removes a field. Removing required fields leaves an incomplete document.

Change resource type¶

osc.apply_project(status=OscStatus.PLANNED, workflows=["new-workflow"])
assert "osc:project" not in product.extra_fields
osc.apply_product(status=OscStatus.ONGOING, project="ocean-science")
assert "osc:workflows" not in product.extra_fields

Both apply methods replace their supported fields: omitted optional arguments clear existing values. apply_project() removes product-only fields; apply_product() removes project workflows. Individual setters do not enforce these relationships.

Attach themes, contacts, and links¶

Themes and contacts use their own STAC extensions, not osc: fields. Use the respective PySTAC extension APIs and declare their schemas when adding them. OSC uses theme concepts under https://github.com/stac-extensions/osc#theme by default. Project contacts use roles technical_officer and consortium_member where applicable.

Use pystac.Link(rel="related", target=...) for resources named in OSC metadata and themes. The wrapper does not create these links automatically. Projects can contain products as child Collections; products can contain other catalogs or data Items.

Apply fields to Items and Catalogs¶

OscExtension.ext() also accepts Items and Catalogs. The same apply methods work on each; Item fields are written into properties, while Catalog and Collection fields are written into extra_fields. Mirror a product's metadata onto its Items explicitly when needed for search.

Assets, item asset definitions, and links are not OSC field targets. There is no OSC summaries helper. Upstream does not validate Collection summaries and recommends using the existing top-level Collection fields instead.

See the upstream specification and field reference.