Object Oriented Linked Data Schema

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.¶

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.¶

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."¶

This Internet-Draft will expire on 4 April 2025.¶

Copyright Notice

Copyright (c) 2024 IETF Trust and the persons identified as the document authors. All rights reserved.¶

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶

Table of Contents

1. Introduction

The core idea is that an OO-LD document is always both a valid JSON-SCHEMA and a JSON-LD remote context ( != JSON-LD document). In this way a complete OO-LD class / schema hierarchy is consumeable by JSON-SCHEMA-only and JSON-LD-only tools while OO-LD aware tools can provide extended features on top (e.g. UI autocomplete dropdowns for string-IRI fields based e.g. on a SPARQL backend, SHACL shape or JSON-LD frame generation).¶

A minimal example:¶

{
  "@context": {
    "schema": "http://schema.org/",
    "name": "schema:name"
  },
  "title": "Person",
  "type": "object",
  "properties": {
    "name": {
      "type": "string",
      "description": "First and Last name"
    }
  }
}

Please note that OO-LD schema documents MUST not be interpreted as JSON-LD documents because this would apply @context on the schema itself. The motivation behind this is to have a single document so schemas can be aggregated using both the JSON-SCHEMA $ref and the JSON-LD remote @context pointing the same resource.¶

%%{init: {'theme': 'neutral' } }%%
classDiagram
    class OOLD_Class_A {
        JSON-SCHEMA + JSON-LD
        @context: ...
        properties: a...
    }

    class OOLD_Class_B {
        JSON-SCHEMA + JSON-LD
        @context: ./A
        allOf: ./A
        properties: b...
    }

    class OOLD_Instance_B {
        JSON
        @context: ./B
        $schema: ./B
        a: ...
        b: ...
    }

    OOLD_Class_A <-- OOLD_Class_B: extends

    OOLD_Class_B <-- OOLD_Instance_B: type

2. Conventions and Definitions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶

3. Security Considerations

Both schemas and instances are JSON values. As such, all security considerations defined in RFC 8259 [RFC8259] apply.¶

Instances and schemas are both frequently written by untrusted third parties, to be deployed on public Internet servers. Implementations should take care that the parsing and evaluating against schemas does not consume excessive system resources. Implementations MUST NOT fall into an infinite loop.¶

A malicious party could cause an implementation to repeatedly collect a copy of a very large value as an annotation. Implementations SHOULD guard against excessive consumption of system resources in such a scenario.¶

Servers MUST ensure that malicious parties cannot change the functionality of existing schemas by uploading a schema with a pre-existing or very similar $id.¶

Individual OO-LD Schema extensions are liable to also have their own security considerations. Consult the respective specifications for more information.¶

Schema authors should take care with $comment contents, as a malicious implementation can display them to end-users in violation of a spec, or fail to strip them if such behavior is expected.¶

A malicious schema author could place executable code or other dangerous material within a $comment. Implementations MUST NOT parse or otherwise take action based on $comment contents.¶

4. IANA Considerations

5. References

Acknowledgments

TODO acknowledge.¶

Author's Address