Use schema specified in the instance using "$schema"

[mikehwang]

I would like to have JSON instances specify the custom JSON schema by having instances use the $schema property. This is a valid use of JSON schema per this page on $schema.

I've poked around the library and I see this:

def validate(instance, schema, cls=None, *args, **kwargs):

But what I would like is a convenience version of that:

def validate(instance, cls=None, *args, **kwargs):

Where this validate would grab and use the schema specified in the $schema property. Does this already exist? Otherwise wouldn't this be a cool feature to add?

Thanks!

[Julian]

$schema is a thing that does that for schemas, not instances. Instances are not presumed to have meaningful keys.

…

On Mar 8, 2017 17:59, "Michael Hwang" ***@***.***> wrote: I would like to have JSON instances specify the custom JSON schema by having instances use the $schema property. This is a valid use of JSON schema per this page on $schema <https://spacetelescope.github.io/understanding-json-schema/reference/schema.html> . I've poked around the library and I see this: def validate(instance, schema, cls=None, *args, **kwargs): But what I would like is a convenience version of that: def validate(instance, cls=None, *args, **kwargs): Where this validate would grab the schema specified in the $schema property. Does this already exist? Otherwise wouldn't this be a cool feature to add? Thanks! — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#327>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAUIXiITR96K0e2FbAvd6MHNmMJ3p6t7ks5rjzLIgaJpZM4MXbCa> .

[mikehwang]

I understand that schemas are metadata for the data (instances). What I'm looking for is described in this SO post.

A given JSON can be made self-describing if it had a $schema property or an equivalent.

[Julian]

Yeah, it makes sense :), although in that answer is also "Although other tools wouldn't pick up on this automatically, it would be obvious to any other developers what you were doing."

Basically, jsonschema could never make assumptions about whether parts of your instance do or don't mean things, even about JSON Schema.

Is the convenience version really that much more convenient than just passing in e.g. requests.get(instance["$schema"]).json()?

[mikehwang]

Basically, jsonschema could never make assumptions about whether parts of your instance do or don't mean things, even about JSON Schema.

Yes I think I see that supporting self-describing JSONs is outside the scope of this library and JSON schema. What's missing is a standardization of the self-describing bit.

Is the convenience version really that much more convenient than just passing in e.g. requests.get(instance["$schema"]).json()?

I wasn't just looking for just convenience rather a suitable, permanent home for this ;)

[Julian]

Gonna close this for now, but if you have any further thoughts lemme know certainly.