Flattening doc with node references instead of node object?

[zaliqarosli]

To be able to externally reference nodes in an RDF graph, it is important that nodes have an identifier. IRIs are a fundamental concept of Linked Data, for nodes to be truly linked, dereferencing the identifier should result in a representation of that node. This may allow an application to retrieve further information about a node.

Hi, I have a node object with a property whose value is a list of node identifiers. Similarly to how contexts can be referenced using a URL, these children nodes are referenced from the main node object by its identifier, and are not connected by the child node object itself. I have not been able to find an example of this. Is this at all possible?

Example:

{
    "@context": [ "https://raw.githubusercontent.com/ReproNim/schema-standardization/master/contexts/generic",
        "https://raw.githubusercontent.com/ReproNim/schema-standardization/master/activities/MedicalHistory-LORIS/medicalhistory_context"
    ],
    "@type": "https://raw.githubusercontent.com/ReproNim/schema-standardization/master/schemas/Activity",
    "@id": "medicalhistory_sectionA",
    "prefLabel": "Section A of Medical History Instrument",
    "altLabel": "medicalhistory_sectionA",
    "description": "Section A of Medical History Instrument",
    "schemaVersion": "0.0.1",
    "version": "0.0.1",
    "preamble": "A. Arthritis",
    "ui": {
        "inputType": "section",
        "order": [
            "https://raw.githubusercontent.com/ReproNim/schema-standardization/master/activities/MedicalHistory-LORIS/items/medicalhistory_1",
            "https://raw.githubusercontent.com/ReproNim/schema-standardization/master/items/age_text"
        ],
        "shuffle": false
    }
}

where this doc would flatten out to include, in the resulting graph, the node object defined in https://raw.githubusercontent.com/ReproNim/schema-standardization/master/activities/MedicalHistory-LORIS/items/medicalhistory_1.

In other words, how would I dereference a node's identifier without directly adding its object into the main jsonld doc?

[pchampin]

Short answer is no, JSON-LD algorithm will not dereference these IRI.

It is important to understand that the URL (or list of URLs) given to @context plays a very different role from the IRIs used in most other places in JSON-LD (including the values of your order property):

• the context URLs are really URLs, used as locators, meant to be dereferenced (or retrieved from a cache) to populate the active context;
• the IRIs used elsewhere are mere identifiers -- they denote a resource, and they may or may not dereference (although Linked Data Principles recomend that they do).

[zaliqarosli]

@pchampin thank you for your quick response. just to clarify, is it okay practice to opt for referencing nodes by their identifier rather than including the node objects themselves?

[pchampin]

is it okay practice to opt for referencing nodes by their identifier rather than including the node objects themselves?

It's more than okay. It is the core principle of linked data :-)