TA-NP-backportquery

This is a draft proposal to extend the Subscriptions-based Notified Pull with related query and the backport-related-query extension to the Task resource.

The backport-related-query extension is a way to add a queryType and query to:

• SubscriptionStatus.notificationEvent
• SubscriptionTopic.notificationShape
• (and also the Basic resource, but this is mainly for R4 compatibility)

and this allows implementation of the Notified Pull pattern within the Subscription framework.

The existing (Dutch) Technical Agreement Notified Pull is Task based.

I’d suggest to explicitly make the extension applicable to at least Task resource (possibly Parameters would be a candidate as well).

This would give us:

• a unified way to exchange queryType+querystring couples within various FHIR exchange patterns, i.e. within the Subscription framework as well as within Task exchanges
• explicit semantics, i.e. a way for a valueString to make explicit that “I am a query” - thus enabling clients to act accordingly
• explicit semantics for queryType as well.

It would make the Subscription-based notified pull “an” implementation of a Notified Pull pattern not “the” implementation of the NP pattern. Per use case implementers can decide whether Subscription, Task, or something else is the best option for such a NP implementation.

The existing backport-related-query extension contains both queryType and query. Since for Task the queryType would land in Task.input and the query in Task.value[x], the existing extension would need to be split in two.

See: Task-MyTask.json.html, StructureDefinition-query.html and StructureDefinition-queryType.html for a sketch.

Github code

Github pages with readble IG