Re: [apps-discuss] Describing JSON document formats

[Phillip Hallam-Baker <[e-mail]>]

On Fri, Nov 30, 2012 at 11:34 AM, Cyrus Daboo <[e-mail]> wrote:

> Hi folks,
> <https://datatracker.ietf.org/**doc/draft-douglass-timezone-**service/<https://datatracker.ietf.org/doc/draft-douglass-timezone-service/>>
> and <https://datatracker.ietf.org/**doc/draft-kewisch-et-al-**
> icalendar-in-json/<https://datatracker.ietf.org/doc/draft-kewisch-et-al-icalendar-in-json/>>
> both define JSON document formats.
>
> In the former case, the spec defines the semantics of the response - we
> choose to use <https://datatracker.ietf.org/**
> doc/draft-newton-json-content-**rules/<https://datatracker.ietf.org/doc/draft-newton-json-content-rules/>>
> as the way to describe that.
>
> In the later case, the spec defines a mapping of syntax only, with the
> actual semantics primarily determined by the underlying iCalendar
> specification. In that case we choose to use ABNF to represent the document
> syntax.
>
> My question is, is there any right way to describe a JSON document format?
> I know there are various JSON schema proposals out there, of which
> draft-newton-json-content-**rules was the one I liked the most, and
> obviously I would be interested in seeing that document proceed. Any
> thoughts?


I think it would be very useful to have a mechanism that allowed JSON
formats to be mapped onto data structures and back.

I think that a mechanism that looked anything like XML Schema with the
maximum and minimum values for integers or with regular expressions and
such should be left at the door.

I also think that there is no need to use JSON syntax for the purpose of
defining the data structures.


Good:

Structure Account
    String Username
    String Realm
    DateTime Created


Bad:

Structure Widget
    Integer Height { min=1, max=142}
    Integer Width {min=1, max=23}


I have written quite a few XML Schema specs and I have never ever found a
need for more than about 10% of the features. It is not necessary to
specify the minimum and maximum number of occurrences. The lower bound is
always 0 or 1, the upper bound is always 1 or infinity.

Schema validation is bunk.


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Website: http://hallambaker.com/