JSON Reference
draft-pbryan-zyp-json-ref-01

Abstract

JSON Reference allows a JSON value to reference another JSON value in a JSON document.

Status of this Memo

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

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This Internet-Draft will expire on May 28, 2012.

Copyright Notice

Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved.

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Table of Contents

• 1. Introduction
• 2. Conventions
• 3. Syntax
• 4. Resolution
• 5. Error Handling
• 6. Media Type
• 7. IANA Considerations
• 8. Security Considerations
• 9. References
• Appendix A. Acknowledgements
• Appendix B. Examples
• Authors' Addresses

1. Introduction

This specification defines a JSON [RFC4627] structure which allows a JSON value to reference another JSON value in a JSON document. This provides the basis for transclusion in JSON: the use of a target resource as an effective substitute for the reference.

2. Conventions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

3. Syntax

A JSON Reference is a JSON object, which contains a member named "$ref", which has a JSON string value. Example:

{ "$ref": "http://example.com/example.json#/foo/bar" }
         

If a JSON value does not have these characteristics, then it SHOULD NOT be interpreted as a JSON Reference.

The "$ref" string value contains a URI [RFC3986], which identifies the location of the JSON value being referenced. It is an error condition if the string value does not conform to URI syntax rules. Any members other than "$ref" in a JSON Reference object SHALL be ignored.

4. Resolution

Resolution of a JSON Reference object SHOULD yield the referenced JSON value. Implementations MAY choose to replace the reference with the referenced value.

If the URI contained in the JSON Reference value is a relative URI, then the base URI resolution MUST be calculated according to [RFC3986], section 5.2. Resolution is performed relative to the referring document.

If a URI contains a fragment identifier, then the fragment should be resolved per the fragment resolution mechansim of the referrant document. If the representation of the referrant document is JSON, then the fragment identifier SHOULD be interpreted as a [JSON Pointer].

5. Error Handling

In the event of an error condition, evaluation of the JSON Reference SHOULD fail to complete.

6. Media Type

Documents that use JSON Reference SHOULD include a media type parameter: application/json; profile=http://json-schema.org/json-ref or refer to a schema that extends http://json-schema.org/json-ref.

7. IANA Considerations

This draft includes no request to IANA.

8. Security Considerations

A JSON Reference is not guaranteed to resolve to a JSON value. Implementations of this specification SHOULD take appropriate precautions.

Documents containing JSON References can be structured to resolve cyclically. Implementations SHOULD include appropriate checks to prevent such structures from resulting in infinite recursion or iteration.

9. References

Appendix A. Acknowledgements

The authors acknowledge the following individuals for their contributed feedback, which influenced this specification:

• Bob Aman, Francis Galiegue.

Appendix B. Examples

TBD.

Authors' Addresses