json - Standard way of referencing an object by identity (for, eg, circular references)?

Question

Is there a standard way of referencing objects by identity in JSON? For example, so that graphs and other data structures with lots of (possibly circular) references can be sanely serialized/loaded?

Edit: I know that it's easy to do one-off solutions (“make a list of all the nodes in the graph, then …”). I'm wondering if there is a standard, generic, solution to this problem.

Answer 1

I was searching on this same feature recently. There does not seem to be a standard or ubiquitous implementation for referencing in JSON. I found a couple of resources that I can share:

• The Future for JSON Referencing

http://groups.google.com/group/json-schema/browse_thread/thread/95fb4006f1f92a40 - This is just a discussion on id-based referencing.

• JSON Referencing in Dojo

http://www.sitepen.com/blog/2008/06/17/json-referencing-in-dojo/ - An implementation in Dojox (extensions for the Dojo framework) - discusses id-based and path based referencing.

• JSONPath - XPath for JSON

http://goessner.net/articles/JsonPath/ - This seems to be an attempt at establishing a standard for path based JSON referencing - maybe a small subset of XPath (?). There seems to be an implementation here but I kept getting errors on the download section - you might have better luck. But again this is no where close to a standard yet.