Stream: bulk data
Topic: Export Response Resource Extensions
Nick Robison (Oct 07 2019 at 14:13):
Hi folks,
Quick question, we're looking at updating our export implementation to return the checksum and file size (in bytes) for each resource. Looks like the spec only defines an extension field for the base resource, what's the recommended way of adding additional per-file metadata?
John Moehrke (Oct 07 2019 at 14:24):
Sounds like you are looking for a Signature. Look at Provenance which provides a generic way to describe the provenance and include a Signature.
Nick Robison (Oct 07 2019 at 14:35):
That's definitely an option we've looked at. If possible, we'd like to keep the information alongside the file URL, to make it easy for developers to grab the necessary file context when handling a download, but definitely an option to consider.
Dan Gottlieb (Oct 07 2019 at 14:50):
I think this is an error in the spec since IIRC the intent was to allow extension elements at the file level as well. Client developers - would this be a breaking change where your client would fail if an extension field is present in objects in the complete status body's "output" array or would these elements just be ignored by default?
Dan Gottlieb (Oct 07 2019 at 14:50):
@Josh Mandel do you know if this would fit under the technical correction category of IG changes?
Michele Mottini (Oct 07 2019 at 15:17):
@Dan Gottlieb don't know, I have to check
Josh Mandel (Oct 08 2019 at 06:33):
We definitely intended to allow extension at any level in JSON -- following the CDS Hooks model.
Josh Mandel (Oct 08 2019 at 06:33):
At the very least, we can include a note to this effect as part of the technical correction, even if we don't change the formal requirements.
Josh Mandel (Oct 08 2019 at 06:35):
Added GF#24912
Nick Robison (Oct 08 2019 at 14:49):
Thanks folks! We'll go ahead and implement the file level extensions. Thanks for chiming in so quickly!
Nick Robison (Oct 08 2019 at 15:10):
Following up, have there been discussions around name spacing the extension keys? I feel like we had some chats about URLs vs dot notation (e.g. gov.cms.dpc), any suggestions or consensus?
Isaac Vetter (Oct 10 2019 at 23:41):
Cds hooks uses reverse domain name notation. Feels like a good practice, regardless of the spec.
Josh Mandel (Oct 11 2019 at 02:17):
Well, URLs can be good practice, too. The basic advice is "pick something unlikely to clash with other implementers".
Michele Mottini (Oct 14 2019 at 17:20):
I finally checked: no, extension inside the output array objects won't break our client
Last updated: Apr 12 2022 at 19:14 UTC
