Presently working on WFCORE-4360 adding support for expression resolution
backed by a credential store - the main barrier is going to be the solution
to bridge expression resolution with a subsystem provided component.
I am wondering if the following is going to be viable to support a
configurable expression resolver from a subsystem.
I see the RuntimeExpressionResolver is created very early in the boot
process, however at the time it is created the CapabilityRegistry is also
available. This is making me think if the CapabilityRegistry can be passed
in to the RuntimeExpressionResolver.
I would then imagine the resource handling expression resolution would
register a non-dynamic capability which exposes an expression resolver
runtime API. This in turn may also need to cross reference a credential
store which would also need to be accessible using the runtime API of a
At the time of expression resolution the RuntimeExpressionResolver would
then check the CapabilityRegistry to see if an expression resolver has been
registered and attempt to use it falling back to vault then default
ModelNode resolution if it does not resolve the expression.
Using a runtime API I suspect I would likely need to trigger the
initialisation of these APIs at the start of Stage.RUNTIME - that looks
feasible by adding a stage to Stage.RUNTIME with addFirst test to true -
maybe to be safe these should also start on demand based on first access.