Describo

All about contexts ​

A valid context is a crucial part of an RO Crate file and this property of the profile allows you to provide one for the classes and properties defined in the profile.

From the section on contexts in the JSON-LD specification:

INFO

When two people communicate with one another, the conversation takes place in a shared environment, typically called "the context of the conversation". This shared context allows the individuals to use shortcut terms, like the first name of a mutual friend, to communicate more quickly but without losing accuracy. A context in JSON-LD works in the same way. It allows two applications to use shortcut terms to communicate with one another more efficiently, but without losing accuracy.

The bare minimum RO-Crate context ​

Following is a stripped down example of the structure of an RO-Crate file with the RO Crate context:

JSON
{
    @context: "https://w3id.org/ro/crate/1.1/context",
    @graph: [
        ...
    ]
}

In this instance the context is a string. But it can be an object or array of things as in the following example:

  • An array with the RO Crate context.
JSON
{
    @context: [
        "https://w3id.org/ro/crate/1.1/context"
    ],
    @graph: [
        ...
    ]
}

A context including DublinCore and FOAF vocabs ​

In the following example, the context is an array containing the RO Crate context along with Friend of a Friend (FOAF) and Dublin Core Terms (DCTerms). In this example we are adding in the additional ontologies and namespacing them. We'll see how to use this further on.

JSON
{
    @context: [
        "https://w3id.org/ro/crate/1.1/context",
        { "foaf": "http://xmlns.com/foaf/0.1" },
        { "dcterms": "https://www.dublincore.org/specifications/dublin-core/dcmi-terms/" }
    ],
    @graph: [
        ...
    ]
}
  • As above but with some custom definitions as well:
JSON
{
    @context: [
        "https://w3id.org/ro/crate/1.1/context",
        { "foaf": "http://xmlns.com/foaf/0.1" },
        { "dcterms": "https://www.dublincore.org/specifications/dublin-core/dcmi-terms/" },
        {
            somePropertyInYourDomain: "https://your domain/path/to/definition#somePropertyInYourDomain"
        }
    ],
    @graph: [
        ...
    ]
}

Example showing usage in Describo Profile ​

Now, when you create a Describo profile, you can use the array form to store your custom context in the profile itself. Then, in your input definitions you can do:

  • Using FOAF and DC Terms (abbreviated for clarity)
JSON
{
    classes: {
        Dataset: {
            ...,
            inputs: [
                {
                    id: `http://xmlns.com/foaf/0.1/#term_family_name`,
                    name: 'foaf:family_name',
                    ...
                },
                {
                    id: `https://www.dublincore.org/specifications/dublin-core/dcmi-terms/#abstract`,
                    name: 'dcterms:abstract'
                }
            ]
        }
    }
}

Then, when Describo emits the user created crate, it will come with a context that describes the data accurately because all of the things the user can do with your profile, match the context you provide.

To define a context for your profile in the crate add a top level key context:

JSON
{
    "metadata": {
        "name": "A profile with all primitives and groups",
        "description": "A profile with entries for each of the supported datatypes",
        "version": 0.1,
        "warnMissingProperty": true
    },
    "context": [
        "https://w3id.org/ro/crate/1.1/context",
        { "foaf": "http://xmlns.com/foaf/0.1" },
        { "dcterms": "https://www.dublincore.org/specifications/dublin-core/dcmi-terms/" }
        {
            somePropertyInYourDomain: "https://your domain/path/to/definition#somePropertyInYourDomain"
        }
    ],
    ...
}