Internet Engineering Task Force P. Bryan, Ed.
Internet-Draft ForgeRock US, Inc.
Intended status: Informational December 4, 2011
Expires: June 6, 2012
JSON Patch
draft-pbryan-json-patch-03
Abstract
JSON Patch defines the media type "application/json-patch", a JSON
document structure for expressing a sequence of partial modifications
to 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 June 6, 2012.
Copyright Notice
Copyright (c) 2011 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 Expires June 6, 2012 [Page 1]
Internet-Draft JSON Patch December 2011
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Document Structure . . . . . . . . . . . . . . . . . . . . . . 3
4. Operations . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4.1. add . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2. remove . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.3. replace . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.4. move . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.5. test . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5. Error Handling . . . . . . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
7. Security Considerations . . . . . . . . . . . . . . . . . . . 6
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
9.1. Normative References . . . . . . . . . . . . . . . . . . . 6
9.2. Informative References . . . . . . . . . . . . . . . . . . 7
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 7
A.1. Adding an Object Member . . . . . . . . . . . . . . . . . 7
A.2. Adding an Array Element . . . . . . . . . . . . . . . . . 7
A.3. Removing an Object Member . . . . . . . . . . . . . . . . 8
A.4. Removing an Array Element . . . . . . . . . . . . . . . . 8
A.5. Replacing a Value . . . . . . . . . . . . . . . . . . . . 9
A.6. Moving a Value . . . . . . . . . . . . . . . . . . . . . . 9
A.7. Moving an Array Element . . . . . . . . . . . . . . . . . 10
A.8. Testing a Value: Success . . . . . . . . . . . . . . . . . 10
A.9. Testing a Value: Error . . . . . . . . . . . . . . . . . . 11
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 11
Bryan Expires June 6, 2012 [Page 2]
Internet-Draft JSON Patch December 2011
1. Introduction
JavaScript Object Notation (JSON) [RFC4627] is a common format for
the exchange and storage of structured data. HTTP PATCH [RFC5789]
extends HTTP [RFC2616] with a method to perform partial modifications
to resources.
The JSON Patch media type "application/json-patch" is a JSON document
structure for expressing a sequence of partial modifications to a
JSON document, suitable for use with the HTTP PATCH method.
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 RFC 2119 [RFC2119].
3. Document Structure
A JSON Patch document contains a JSON array of objects. Each object
contains a single operation to apply to the target JSON document.
A sample JSON Patch document:
[
{ "test": "/a/b/c", value: "foo" },
{ "remove": "/a/b/c" },
{ "add": "/a/b/c", "value": [ "foo", "bar" ] },
{ "replace": "/a/b/c", "value": 42 },
{ "move": "/a/b/c", to: "/a/b/d" }
]
Evaluation of a JSON Patch document begins with a target JSON
document to modify. Operations are applied sequentially in the order
they appear in the array. Each operation in the sequence is applied
to the target document. The resulting modified document becomes the
target for the next operation. The process repeats until all
operations are successfully applied.
4. Operations
The operation to perform is expressed in the name of a member in the
operation object; it's value is a string containing a [JSON Pointer],
which references the value for which to apply the operation. It is
an error condition if an operation object contains more than one
Bryan Expires June 6, 2012 [Page 3]
Internet-Draft JSON Patch December 2011
operation member.
4.1. add
The "add" operation adds a new value into the target document. The
value to be added is specified in the operation object's "value"
member.
If adding to an object, it is an error condition if the member to be
added in the object already exists.
If adding to an array, all elements at or above the specified index
are shifted one position to the right. It is an error condition if
the specified index is greater than the number of elements in the
existing array.
4.2. remove
The "remove" operation removes a value from the target document.
If removing an element from an array, all elements above the
specified index are shifted one position to the left.
It is an error condition if the value to be removed does not exist.
4.3. replace
The "replace" operation replaces an existing value in the target
document with a new value. The value to replace the existing value
with is specified in the operation object's "value" member.
This operation is semantically equivalent to expressing a "remove"
operation for a value, followed immediately by an "add" operation at
the same location of the removed value.
It is an error condition if the value to be replaced does not exist.
4.4. move
The "move" operation moves a value from one location to another
within the target document. The location to move the value to is
specified in the operation object's "to" member, a string containing
a JSON Pointer.
This operation is semantically equivalent to expressing a "remove"
operation, followed immediately by an "add" operation with the
removed value.
Bryan Expires June 6, 2012 [Page 4]
Internet-Draft JSON Patch December 2011
It is an error condition if the value to be moved does not exist, or
if the location to move the value to already has a value.
4.5. test
The "test" operation tests that a value in the target document is
equal to the specified value. The value to test for is specified in
the operation object's "value" member.
It is an error condition if the value in the target document is not
equal to the specified value.
5. Error Handling
In the event of an error condition, evaluation of the JSON Patch
document SHOULD terminate and application of the entire patch
document MUST NOT be deemed successful.
6. IANA Considerations
The Internet media type for a JSON Patch document is application/
json-patch.
Type name: application
Subtype name: json-patch
Required parameters: none
Optional parameters: none
Encoding considerations:
Per JSON [RFC4627]: 8bit if UTF-8; binary if UTF-16 or UTF-32.
Security considerations:
See Security Considerations in section 8.
Interoperability considerations: N/A
Published specification:
draft-pbryan-json-patch-03
Applications that use this media type:
Applications that manipulate JSON documents.
Bryan Expires June 6, 2012 [Page 5]
Internet-Draft JSON Patch December 2011
Additional information:
Magic number(s): N/A
File extension(s): .json-patch
Macintosh file type code(s): TEXT
Person & email address to contact for further information:
Paul C. Bryan <paul.bryan@forgerock.com>
Intended usage: COMMON
Restrictions on usage: none
Author: Paul C. Bryan <paul.bryan@forgerock.com>
Change controller: Paul C. Bryan <paul.bryan@forgerock.com>
7. Security Considerations
This specification has the same security considerations as JSON
[RFC4627] and JSON Pointer [JSON Pointer].
8. Acknowledgements
The following individuals contributed ideas, feedback and wording,
which contributed to the content of this specification:
Mike Amundsen, Paul Davis, Dean Landolt, Randall Leeds, Mark
Nottingham, Julian Reschke, Eli Stevens.
The structure of a JSON Patch document was initially informed by the
XML Patch document [RFC5261] specification.
9. References
9.1. Normative References
[JSON Pointer]
Bryan, P. and K. Zyp, "JSON Pointer", October 2011, <http:
//tools.ietf.org/html/draft-pbryan-zyp-json-pointer-02>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
Bryan Expires June 6, 2012 [Page 6]
Internet-Draft JSON Patch December 2011
[RFC4627] Crockford, D., "The application/json Media Type for
JavaScript Object Notation (JSON)", RFC 4627, July 2006.
9.2. Informative References
[RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
[RFC5261] Urpalainen, J., "An Extensible Markup Language (XML) Patch
Operations Framework Utilizing XML Path Language (XPath)
Selectors", RFC 5261, September 2008.
[RFC5789] Dusseault, L. and J. Snell, "PATCH Method for HTTP",
RFC 5789, March 2010.
Appendix A. Examples
A.1. Adding an Object Member
An example target JSON document:
{
"foo": "bar"
}
A JSON Patch document:
[
{ "add": "/baz", "value": "qux" }
]
The resulting JSON document:
{
"baz": "qux",
"foo": "bar"
}
A.2. Adding an Array Element
An example target JSON document:
{
"foo": [ "bar", "baz" ]
}
Bryan Expires June 6, 2012 [Page 7]
Internet-Draft JSON Patch December 2011
A JSON Patch document:
[
{ "add": "/foo/1", "value": "qux" }
]
The resulting JSON document:
{
"foo": [ "bar", "qux", "baz" ]
}
A.3. Removing an Object Member
An example target JSON document:
{
"baz": "qux",
"foo": "bar"
}
A JSON Patch document:
[
{ "remove": "/baz" }
]
The resulting JSON document:
{
"foo": "bar"
}
A.4. Removing an Array Element
An example target JSON document:
{
"foo": [ "bar", "qux", "baz" ]
}
A JSON Patch document:
[
{ "remove": "/foo/1" }
]
The resulting JSON document:
Bryan Expires June 6, 2012 [Page 8]
Internet-Draft JSON Patch December 2011
{
"foo": ["bar", "baz"]
}
A.5. Replacing a Value
An example target JSON document:
{
"baz": "qux",
"foo": "bar"
}
A JSON Patch document:
[
{ "replace": "/baz", "value": "boo" }
]
The resulting JSON document:
{
"baz": "boo",
"foo": "bar"
}
A.6. Moving a Value
An example target JSON document:
{
"foo": {
"bar": "baz",
"waldo": "fred"
}
"qux": {
"corge": "grault"
}
}
A JSON Patch document:
[
{ "move": "/foo/waldo", to: "/qux/thud" }
]
The resulting JSON document:
Bryan Expires June 6, 2012 [Page 9]
Internet-Draft JSON Patch December 2011
{
"foo": {
"bar": "baz"
}
"qux": {
"corge": "grault",
"thud": "fred"
}
}
A.7. Moving an Array Element
An example target JSON document:
{
"foo": [ "all", "grass", "cows", "eat" ]
}
A JSON Patch document:
[
{ "move": "/foo/1", "to": "/foo/3" }
]
The resulting JSON document:
{
"foo": [ "all", "cows", "eat", "grass" ]
}
A.8. Testing a Value: Success
An example target JSON document:
{
"baz": "qux",
"foo": [ "a", 2, "c" ]
}
A JSON Patch document, which will result in successful evaluation:
[
{ "test": "/baz", "value": "qux" },
{ "test": "/foo/1", "value": 2 }
]
Bryan Expires June 6, 2012 [Page 10]
Internet-Draft JSON Patch December 2011
A.9. Testing a Value: Error
An example target JSON document:
{
"baz": "qux",
}
A JSON Patch document, which will result in an error condition:
[
{ "test": "/baz", "value": "bar" }
]
Author's Address
Paul C. Bryan (editor)
ForgeRock US, Inc.
201 NE Park Plaza Drive Suite 196
Vancouver, WA 98684
USA
Phone: +1 604 783 1481
Email: paul.bryan@forgerock.com
Bryan Expires June 6, 2012 [Page 11]