Internet Engineering Task Force P. Bryan, Ed. Internet-Draft Salesforce.com Intended status: Informational K. Zyp Expires: March 20, 2013 SitePen (USA) September 16, 2012 JSON Reference draft-pbryan-zyp-json-ref-03 Abstract JSON Reference allows a JSON value to reference another 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. 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 http://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 March 20, 2013. Copyright Notice Copyright (c) 2012 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 (http://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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Bryan & Zyp Expires March 20, 2013 [Page 1] Internet-Draft JSON Reference September 2012 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . 3 5. Error Handling . . . . . . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 7. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 8. Normative References . . . . . . . . . . . . . . . . . . . . . 4 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . . 4 Appendix B. Examples . . . . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 Bryan & Zyp Expires March 20, 2013 [Page 2] Internet-Draft JSON Reference September 2012 1. Introduction This specification defines a JSON [RFC4627] structure which allows a JSON value to reference another 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]. Bryan & Zyp Expires March 20, 2013 [Page 3] Internet-Draft JSON Reference September 2012 5. Error Handling In the event of an error condition, evaluation of the JSON Reference SHOULD fail to complete. 6. IANA Considerations This draft includes no request to IANA. 7. 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. 8. Normative References [JSON-Pointer] Bryan, P., Zyp, K., and M. Nottingham, "JSON Pointer", draft-ietf-appsawg-json-pointer-04 (work in progress), September 2012. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005. [RFC4627] Crockford, D., "The application/json Media Type for JavaScript Object Notation (JSON)", RFC 4627, July 2006. Appendix A. Acknowledgements The following individuals contributed ideas, feedback and wording to this specification: Bob Aman, Francis Galiegue. Bryan & Zyp Expires March 20, 2013 [Page 4] Internet-Draft JSON Reference September 2012 Appendix B. Examples TBD. Authors' Addresses Paul C. Bryan (editor) Salesforce.com Phone: +1 604 783 1481 Email: pbryan@anode.ca Kris Zyp SitePen (USA) Phone: +1 650 968 8787 Email: kris@sitepen.com Bryan & Zyp Expires March 20, 2013 [Page 5]