Thanks for the clarification Felix! Just to confirm though ... if Inventory bundle is later patched/refreshed it would then lead to refresh of Commons Log bundle also. Would that mean framework would be bought down to level 1 and restarted again Chetan Mehrotra
On Mon, Feb 3, 2014 at 2:21 PM, Felix Meschberger <fmesc...@adobe.com> wrote: > Hi > > Am 03.02.2014 um 09:41 schrieb Chetan Mehrotra <chetan.mehro...@gmail.com>: > >> Hi, >> >> For SLING-3264 I was thinking to provide Inventory integration in >> Commons Logs. However the Commons Log bundle starts at level 1 while >> the Inventory bundle starts at Level 5. The log bundle would use the >> ServiceFactory approach to expose the Inventory service and would not >> have required dependency on Inventory API. >> >> So just wanted to confirm that would it be fine to depend on classes >> from a bundle which starts at later start level or not? > > Sure. This is what we are using ServiceFactory and dynamic/delayed import all > over places. See for example the Configuration Admin binding the Apache Felix > SCR bundle. > > So, what seems to boild down to kind of a best practice is to: > > * use ServiceFactory for optional services > * use Import-Package with resolution:=optional to have > static wiring if possible > * use DynamicImport-Package to have dynamic wiring > on-demand > > It is just very important to thouroughly test this to not get inadvertend > ClassNotFoundExceptions, for example if the optional classes appear in the > method signature of a required class (see the > ResourceResolverActivator.getFeaures() method which returns Object to work > around this issue). > > Regards > Felix
