Stream: subscriptions
Topic: Handling unknown parameters in SubscriptionTopic
Jenni Syed (Sep 11 2020 at 20:09):
@Grahame Grieve mentioned that he found an issue during implementation where the specification isn't opinionated on how a server should deal with unknown parameters in the criteria. The FHIR spec normally states you ignore them on a search in general. What should we say?
Jenni Syed (Sep 11 2020 at 20:10):
Some notes from our conversation in breakout: Options: do not recognize or do not support? Error or warning? Should you validate SubscriptionTopic on write?
Error on warning: pro - you know immediately that this won't work vs erring later (on Subscription create or it not going active).
Con: it requires validation of the SubscriptionTopic at write.
Warning or Success on create: con - May be surprising later to the client.
Should we clarify that you should validate SubscriptionTopic on creation and error if not supported (eg: unrecognized resources, criteria, etc) Unless you aren't the one processing ?? EG: if you're just a repository for other systems' topics.
What happens if the param is removed at some point after Subscription? What if the Topic is removed after subscription? We need to consider these for the error set on Subscription.
Grahame Grieve (Sep 13 2020 at 11:55):
unknown parameters are allowed in a search because various stacks add unknown parameters for security/cache control reasons. This doesn't apply in a subscription
Last updated: Apr 12 2022 at 19:14 UTC
