Making a metadata descriptor

Overview

Teaching: 2 min
Exercises: 2 min

Questions

• Which RO-Crate version is used?

• How can the crate self-identify as an RO-Crate?

Objectives

• Add the first entity to the JSON-LD @graph

• Indicate the version of RO-Crate

RO-Crate Metadata descriptor

The first JSON-LD entity to add has the @id value of ro-crate-metadata.json to describe the JSON file itself:

{
    "@id": "ro-crate-metadata.json",
    "@type": "CreativeWork",
    "conformsTo": {"@id": "https://w3id.org/ro/crate/1.1"},
    "about": {"@id": "./"}
}

This required entity, known as the RO-Crate Metadata Descriptor, helps this file self-identify as an RO-Crate Metadata Document, which is conforming to (conformsTo) the RO-Crate specification version 1.1. Notice that the conformsTo URL corresponds to the @context URL version-wise, but they have two different functions. The context brings the defined terms into the metadata document, while the conformance declares which RO-Crate conventions of using those terms are being followed.

RO-Crate versions

This tutorial is written for RO-Crate 1.1, the RO-Crate website will list the current specification version – RO-Crates can generally be upgraded to newer versions following semantic versioning conventions, but check the change log for any important changes. The next development version of the specification, indicated with a -DRAFT status, may still be subject to changes and should only be used with caution.

Key Points

• The RO-Crate Metadata Descriptor describes the JSON-LD file itself

• RO-Crate specifications are versioned

• The version of RO-Crate is indicated using the conformsTo property