Hi!
Another feature discussion is around supporting changing configured values
while the application is running.
This is the push/pull discussion if you remember.
Pull:
In DeltaSpike this was not a first class citizen so to say. It was doable
because ConfigResolver always evaluates all the ConfigSources and does not
cache any resolved values. Thus we defer the caching to each ConfigResolver.
Of course this only works if you always call
ConfigResolver#getPropertyValue("mykey") and not for injected config values or
if you only resolve the configuration once at startup.
Pro:
+ straight forward
+ easy to provide
+ client can define the refresh rate
Con:
- more code at client
- somewhat slower if config values get re-evaluated each time
- application needs to handle caching
Push:
Whenever a configured value gets changed we send an 'event' which can be
observed by the clients. This could be done e.g. in a Swing style with
registering ConfigListeners. Later in a CDI module we could also register a
central ConfigListener which relays this to a CDI Event.
Open Questions from my side: who does trigger this event? And when? Do the
ConfigSources detect any change themselves? Or does the admin need to trigger a
'reload' via JMX or similar?
LieGrue,
strub
