Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?
I will state again that this seems like a large expansion of DS for quite a small use case. It’s limited to existing types which the user can’t change and doesn’t want to use the decorator/delegation pattern for, and that also don’t have a public constructor (i.e. must use a factory to create them). If there is a public constructor then a suitable XML file can be written once and used indefinitely. Tim > On 21 Apr 2017, at 09:06, Neil Bartlett <njbartl...@gmail.com> wrote: > > And which bundle would be passed as the requesting bundle parameter of > getService? SCR itself? > > > > On 21 Apr 2017 08:24, "Peter Kriens" <peter.kri...@aqute.biz > <mailto:peter.kri...@aqute.biz>> wrote: > Well, the ServiceFactory is just a way to indirect the creation of the > actual instance. I do not see why such a pattern theoretically could not be > used for DS as well? > > All the rules could stay the same, however, DS would ask the component > instance for the service instance to register instead of assuming this is > always the component instance. The difference would be that getService() > would only be called once for any given instance since cardinality would be > handled by DS. > > Kind regards, > > Peter Kriens > > > > > > >> On 20 Apr 2017, at 19:26, BJ Hargrave <hargr...@us.ibm.com >> <mailto:hargr...@us.ibm.com>> wrote: >> >> When DS registers your component as a service, it already registers its own >> object implementing ServiceFactory. This is necessary to register the >> service while still allowing delayed activation of your component. So DS's >> ServiceFactory object is called by the framework when someone gets the >> service and then DS will instantiate and activate your service component. >> How many times this is done is controlled by scope of the component: >> singleton, bundle, prototype. >> >> The basic point is that DS must be in charge of constructing and activating >> component instances and so your component implemention ServiceFactory does >> not work with that. With plans to support constructor injection in DS 1.4, >> this is even more important to the DS component model. >> -- >> >> BJ Hargrave >> Senior Technical Staff Member, IBM // office: +1 386 848 1781 >> <tel:(386)%20848-1781> >> OSGi Fellow and CTO of the OSGi Alliance // mobile: +1 386 848 3788 >> <tel:(386)%20848-3788> >> hargr...@us.ibm.com <mailto:hargr...@us.ibm.com> >> >> >> ----- Original message - >> From: Julian Sedding <jsedd...@gmail.com <mailto:jsedd...@gmail.com>> >> Sent by: osgi-dev-boun...@mail.osgi.org >> <mailto:osgi-dev-boun...@mail.osgi.org> >> To: OSGi Developer Mail List <osgi-dev@mail.osgi.org >> <mailto:osgi-dev@mail.osgi.org>> >> Cc: >> Subject: Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS? >> Date: Thu, Apr 20, 2017 9:39 AM >> >> Hi Tim >> >> That's an interesting approach! I hadn't considered using DS but >> handling the service registration myself. >> >> To me it would have felt consistent if registering a ServiceFactory as >> a service using DS had just worked. Next to controlling the scope >> (singleton, bundle, prototype) of a service, a ServiceFactory seems >> suitable to creating service objects by means other than their default >> constructor. Thus, supporting ServiceFactories in DS would make it >> very easy to provide OSGi-glue for arbitrary Java classes that are >> themselves unaware of OSGi. >> >> Of course there is a trade-off between the usefulness of a feature and >> bloating the spec. And I'll leave this decision with you guys. >> >> Regards >> Julian >> >> >> On Thu, Apr 20, 2017 at 12:35 PM, Timothy Ward <tim.w...@paremus.com >> <mailto:tim.w...@paremus.com>> wrote: >> > DS isn’t intended to solve every single use case, rather to make common >> > use cases simple to write and understand. In this case what you want is >> > more advanced, and unlikely to make it into DS as a natively supported >> > pattern. Given that you’re already tied to the core OSGi API >> > (ServiceFactory) then registering the service programatically would still >> > let DS help you with config and service injection. >> > >> > >> > @Component( >> >// Do not let DS provide the service >> >service = {}, >> >configurationPolicy = ConfigurationPolicy.REQUIRE >> > ) &
Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?
And which bundle would be passed as the requesting bundle parameter of getService? SCR itself? On 21 Apr 2017 08:24, "Peter Kriens" <peter.kri...@aqute.biz> wrote: > Well, the ServiceFactory is just a way to indirect the creation of the > actual instance. I do not see why such a pattern theoretically could not be > used for DS as well? > > All the rules could stay the same, however, DS would ask the component > instance for the service instance to register instead of assuming this is > always the component instance. The difference would be that getService() > would only be called once for any given instance since cardinality would be > handled by DS. > > Kind regards, > > Peter Kriens > > > > > > > On 20 Apr 2017, at 19:26, BJ Hargrave <hargr...@us.ibm.com> wrote: > > When DS registers your component as a service, it already registers its > own object implementing ServiceFactory. This is necessary to register the > service while still allowing delayed activation of your component. So DS's > ServiceFactory object is called by the framework when someone gets the > service and then DS will instantiate and activate your service component. > How many times this is done is controlled by scope of the component: > singleton, bundle, prototype. > > The basic point is that DS must be in charge of constructing and > activating component instances and so your component implemention > ServiceFactory does not work with that. With plans to support constructor > injection in DS 1.4, this is even more important to the DS component model. > -- > > BJ Hargrave > Senior Technical Staff Member, IBM // office: +1 386 848 1781 > <(386)%20848-1781> > OSGi Fellow and CTO of the OSGi Alliance // mobile: +1 386 848 3788 > <(386)%20848-3788> > hargr...@us.ibm.com > > > > - Original message - > From: Julian Sedding <jsedd...@gmail.com> > Sent by: osgi-dev-boun...@mail.osgi.org > To: OSGi Developer Mail List <osgi-dev@mail.osgi.org> > Cc: > Subject: Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via > DS? > Date: Thu, Apr 20, 2017 9:39 AM > > Hi Tim > > That's an interesting approach! I hadn't considered using DS but > handling the service registration myself. > > To me it would have felt consistent if registering a ServiceFactory as > a service using DS had just worked. Next to controlling the scope > (singleton, bundle, prototype) of a service, a ServiceFactory seems > suitable to creating service objects by means other than their default > constructor. Thus, supporting ServiceFactories in DS would make it > very easy to provide OSGi-glue for arbitrary Java classes that are > themselves unaware of OSGi. > > Of course there is a trade-off between the usefulness of a feature and > bloating the spec. And I'll leave this decision with you guys. > > Regards > Julian > > > On Thu, Apr 20, 2017 at 12:35 PM, Timothy Ward <tim.w...@paremus.com> > wrote: > > DS isn’t intended to solve every single use case, rather to make common > use cases simple to write and understand. In this case what you want is > more advanced, and unlikely to make it into DS as a natively supported > pattern. Given that you’re already tied to the core OSGi API > (ServiceFactory) then registering the service programatically would still > let DS help you with config and service injection. > > > > > > @Component( > >// Do not let DS provide the service > >service = {}, > >configurationPolicy = ConfigurationPolicy.REQUIRE > > ) > > public class FooServiceFactory implements ServiceFactory { > > > >@Reference // provides FooBuilder instances that are pre-configured > via OSGi > >private FooBuilderFactory fooBuilderFactory; > > > >private ServiceRegistration reg; > > > > @Activate > > void start(BundleContext ctx, Map<String, Object> props, Config > config) { > > reg = ctx.registerService(Foo.class.getName(), this, props); > > } > > > > @Deactivate > > void stop() { > > reg.unregister(); > > } > > > >@Override > >public Foo getService() { > >FooBuilder fooBuilder = fooBuilderFactory.builder(); > >applyConfiguration(fooBuilder); > >return fooBuilder.build(); > >} > > > >private void applyConfiguration(FooBuilder fooBuilder) { > >// apply OSGi configuration to FooBuilder object > >} > > > >... // ungetService omitted for brevity > > > > } > > > > > > Regards, > > > > Tim > > &
Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?
Well, the ServiceFactory is just a way to indirect the creation of the actual instance. I do not see why such a pattern theoretically could not be used for DS as well? All the rules could stay the same, however, DS would ask the component instance for the service instance to register instead of assuming this is always the component instance. The difference would be that getService() would only be called once for any given instance since cardinality would be handled by DS. Kind regards, Peter Kriens > On 20 Apr 2017, at 19:26, BJ Hargrave <hargr...@us.ibm.com> wrote: > > When DS registers your component as a service, it already registers its own > object implementing ServiceFactory. This is necessary to register the service > while still allowing delayed activation of your component. So DS's > ServiceFactory object is called by the framework when someone gets the > service and then DS will instantiate and activate your service component. How > many times this is done is controlled by scope of the component: singleton, > bundle, prototype. > > The basic point is that DS must be in charge of constructing and activating > component instances and so your component implemention ServiceFactory does > not work with that. With plans to support constructor injection in DS 1.4, > this is even more important to the DS component model. > -- > > BJ Hargrave > Senior Technical Staff Member, IBM // office: +1 386 848 1781 > OSGi Fellow and CTO of the OSGi Alliance // mobile: +1 386 848 3788 > hargr...@us.ibm.com > > > - Original message - > From: Julian Sedding <jsedd...@gmail.com> > Sent by: osgi-dev-boun...@mail.osgi.org > To: OSGi Developer Mail List <osgi-dev@mail.osgi.org> > Cc: > Subject: Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS? > Date: Thu, Apr 20, 2017 9:39 AM > > Hi Tim > > That's an interesting approach! I hadn't considered using DS but > handling the service registration myself. > > To me it would have felt consistent if registering a ServiceFactory as > a service using DS had just worked. Next to controlling the scope > (singleton, bundle, prototype) of a service, a ServiceFactory seems > suitable to creating service objects by means other than their default > constructor. Thus, supporting ServiceFactories in DS would make it > very easy to provide OSGi-glue for arbitrary Java classes that are > themselves unaware of OSGi. > > Of course there is a trade-off between the usefulness of a feature and > bloating the spec. And I'll leave this decision with you guys. > > Regards > Julian > > > On Thu, Apr 20, 2017 at 12:35 PM, Timothy Ward <tim.w...@paremus.com> wrote: > > DS isn’t intended to solve every single use case, rather to make common use > > cases simple to write and understand. In this case what you want is more > > advanced, and unlikely to make it into DS as a natively supported pattern. > > Given that you’re already tied to the core OSGi API (ServiceFactory) then > > registering the service programatically would still let DS help you with > > config and service injection. > > > > > > @Component( > >// Do not let DS provide the service > >service = {}, > >configurationPolicy = ConfigurationPolicy.REQUIRE > > ) > > public class FooServiceFactory implements ServiceFactory { > > > >@Reference // provides FooBuilder instances that are pre-configured via > > OSGi > >private FooBuilderFactory fooBuilderFactory; > > > >private ServiceRegistration reg; > > > > @Activate > > void start(BundleContext ctx, Map<String, Object> props, Config config) { > > reg = ctx.registerService(Foo.class.getName(), this, props); > > } > > > > @Deactivate > > void stop() { > > reg.unregister(); > > } > > > >@Override > >public Foo getService() { > >FooBuilder fooBuilder = fooBuilderFactory.builder(); > >applyConfiguration(fooBuilder); > >return fooBuilder.build(); > >} > > > >private void applyConfiguration(FooBuilder fooBuilder) { > >// apply OSGi configuration to FooBuilder object > >} > > > >... // ungetService omitted for brevity > > > > } > > > > > > Regards, > > > > Tim > > > > > >> On 20 Apr 2017, at 11:11, Julian Sedding <jsedd...@gmail.com> wrote: > >> > >> Hi Timothy > >> > >> Thanks for your reply. Using delegation works, I currently use it to > >> solve my use-case. > >&g
Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?
When DS registers your component as a service, it already registers its own object implementing ServiceFactory. This is necessary to register the service while still allowing delayed activation of your component. So DS's ServiceFactory object is called by the framework when someone gets the service and then DS will instantiate and activate your service component. How many times this is done is controlled by scope of the component: singleton, bundle, prototype. The basic point is that DS must be in charge of constructing and activating component instances and so your component implemention ServiceFactory does not work with that. With plans to support constructor injection in DS 1.4, this is even more important to the DS component model. --BJ HargraveSenior Technical Staff Member, IBM // office: +1 386 848 1781OSGi Fellow and CTO of the OSGi Alliance // mobile: +1 386 848 3788hargr...@us.ibm.com - Original message -From: Julian Sedding <jsedd...@gmail.com>Sent by: osgi-dev-boun...@mail.osgi.orgTo: OSGi Developer Mail List <osgi-dev@mail.osgi.org>Cc:Subject: Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?Date: Thu, Apr 20, 2017 9:39 AM Hi TimThat's an interesting approach! I hadn't considered using DS buthandling the service registration myself.To me it would have felt consistent if registering a ServiceFactory asa service using DS had just worked. Next to controlling the scope(singleton, bundle, prototype) of a service, a ServiceFactory seemssuitable to creating service objects by means other than their defaultconstructor. Thus, supporting ServiceFactories in DS would make itvery easy to provide OSGi-glue for arbitrary Java classes that arethemselves unaware of OSGi.Of course there is a trade-off between the usefulness of a feature andbloating the spec. And I'll leave this decision with you guys.RegardsJulianOn Thu, Apr 20, 2017 at 12:35 PM, Timothy Ward <tim.w...@paremus.com> wrote:> DS isn’t intended to solve every single use case, rather to make common use cases simple to write and understand. In this case what you want is more advanced, and unlikely to make it into DS as a natively supported pattern. Given that you’re already tied to the core OSGi API (ServiceFactory) then registering the service programatically would still let DS help you with config and service injection.>>> @Component(> // Do not let DS provide the service> service = {},> configurationPolicy = ConfigurationPolicy.REQUIRE> )> public class FooServiceFactory implements ServiceFactory {>> @Reference // provides FooBuilder instances that are pre-configured via OSGi> private FooBuilderFactory fooBuilderFactory;>> private ServiceRegistration reg;>> @Activate> void start(BundleContext ctx, Map<String, Object> props, Config config) {> reg = ctx.registerService(Foo.class.getName(), this, props);> }>> @Deactivate> void stop() {> reg.unregister();> }>> @Override> public Foo getService() {> FooBuilder fooBuilder = fooBuilderFactory.builder();> applyConfiguration(fooBuilder);> return fooBuilder.build();> }>> private void applyConfiguration(FooBuilder fooBuilder) {> // apply OSGi configuration to FooBuilder object> }>> ... // ungetService omitted for brevity>> }>>> Regards,>> Tim>>>> On 20 Apr 2017, at 11:11, Julian Sedding <jsedd...@gmail.com> wrote:>>>> Hi Timothy>>>> Thanks for your reply. Using delegation works, I currently use it to>> solve my use-case.>>>> However, compared to implementing a ServiceFactory, delegation adds>> some overhead:>>>> - delegation needs to be implemented, which is trivial, but noisy if>> there are lots of methods that need delegating>> - by delegating, my implementation becomes a "provider" of Foo, rather>> than a "consumer", making my bundle more susceptible to changes in>> Foo's API>> - also: delegation is not possible if Foo is a final class>>>> I brought up this topic in order to (a) confirm that my desired>> approach is indeed not possible at the moment and (b) to see if adding>> support for registering custom ServiceFactory implementations via DS>> could be a desirable enhancement for the spec.>>>> Regards>> Julian>>>>>> On Thu, Apr 20, 2017 at 11:22 AM, Timothy Ward <tim.w...@paremus.com> wrote:>>> Have you not considered the following:>>>>>>>>> @Component(configurationPolicy = ConfigurationPolicy.REQUIRE,>>> scope = ServiceScope.BUNDLE)>>> public class FooImpl implements Foo {>>>>>> public @interface Config {>>> // Config definition in here>&g
Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?
Hi Tim That's an interesting approach! I hadn't considered using DS but handling the service registration myself. To me it would have felt consistent if registering a ServiceFactory as a service using DS had just worked. Next to controlling the scope (singleton, bundle, prototype) of a service, a ServiceFactory seems suitable to creating service objects by means other than their default constructor. Thus, supporting ServiceFactories in DS would make it very easy to provide OSGi-glue for arbitrary Java classes that are themselves unaware of OSGi. Of course there is a trade-off between the usefulness of a feature and bloating the spec. And I'll leave this decision with you guys. Regards Julian On Thu, Apr 20, 2017 at 12:35 PM, Timothy Wardwrote: > DS isn’t intended to solve every single use case, rather to make common use > cases simple to write and understand. In this case what you want is more > advanced, and unlikely to make it into DS as a natively supported pattern. > Given that you’re already tied to the core OSGi API (ServiceFactory) then > registering the service programatically would still let DS help you with > config and service injection. > > > @Component( >// Do not let DS provide the service >service = {}, >configurationPolicy = ConfigurationPolicy.REQUIRE > ) > public class FooServiceFactory implements ServiceFactory { > >@Reference // provides FooBuilder instances that are pre-configured via > OSGi >private FooBuilderFactory fooBuilderFactory; > >private ServiceRegistration reg; > > @Activate > void start(BundleContext ctx, Map props, Config config) { > reg = ctx.registerService(Foo.class.getName(), this, props); > } > > @Deactivate > void stop() { > reg.unregister(); > } > >@Override >public Foo getService() { >FooBuilder fooBuilder = fooBuilderFactory.builder(); >applyConfiguration(fooBuilder); >return fooBuilder.build(); >} > >private void applyConfiguration(FooBuilder fooBuilder) { >// apply OSGi configuration to FooBuilder object >} > >... // ungetService omitted for brevity > > } > > > Regards, > > Tim > > >> On 20 Apr 2017, at 11:11, Julian Sedding wrote: >> >> Hi Timothy >> >> Thanks for your reply. Using delegation works, I currently use it to >> solve my use-case. >> >> However, compared to implementing a ServiceFactory, delegation adds >> some overhead: >> >> - delegation needs to be implemented, which is trivial, but noisy if >> there are lots of methods that need delegating >> - by delegating, my implementation becomes a "provider" of Foo, rather >> than a "consumer", making my bundle more susceptible to changes in >> Foo's API >> - also: delegation is not possible if Foo is a final class >> >> I brought up this topic in order to (a) confirm that my desired >> approach is indeed not possible at the moment and (b) to see if adding >> support for registering custom ServiceFactory implementations via DS >> could be a desirable enhancement for the spec. >> >> Regards >> Julian >> >> >> On Thu, Apr 20, 2017 at 11:22 AM, Timothy Ward wrote: >>> Have you not considered the following: >>> >>> >>> @Component(configurationPolicy = ConfigurationPolicy.REQUIRE, >>>scope = ServiceScope.BUNDLE) >>> public class FooImpl implements Foo { >>> >>> public @interface Config { >>> // Config definition in here >>> } >>> >>> @Reference >>> private FooBuilderFactory fooBuilderFactory; >>> >>> private Foo delegate; >>> >>> @Activate >>> void start(Config config) { >>> FooBuilder fooBuilder = fooBuilderFactory.builder(); >>> applyConfiguration(fooBuilder, config); >>> delegate = fooBuilder.build(); >>> } >>> >>> // Deactivation and Foo delegation methods go here >>> … >>> } >>> >>> Regards, >>> >>> Tim >>> On 20 Apr 2017, at 09:30, Julian Sedding wrote: Hi there I have been trying to implement a use-case, but I seem to be running into walls ;) (Disclaimer: I can see multiple ways to implement this, but would like to re-use the dependency injection and lazy instantiation of DS). My aim is to create configured service objects in the way that is normally achieved by using a DS factory component with configuration-policy require. The catch is that the implementation of the objects I want to configure and register as a service is not under my control and is instanciated via a builder obtained from a factory that is registered as an OSGi-service. Sounds a bit complicated, maybe it's clearer in code. @Component( service = Foo.class, configurationPolicy = ConfigurationPolicy.REQUIRE ) public class FooServiceFactory implements ServiceFactory { @Reference // provides FooBuilder instances that are pre-configured via
Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?
Yes, that would solve this issue. Kind regards, Peter Kriens > On 20 Apr 2017, at 14:02, Tim Wardwrote: > > Peter - I assume that you mean that there will be no auto-generated > osgi.service capability. Couldn't that be fixed with an additional annotation > on the component type to add the Provide-Capability to the manifest? > > Tim Ward > > Sent from my iPhone > >> On 20 Apr 2017, at 12:38, Peter Kriens wrote: >> >> But then you loose the DS dependency management on Foo … Since your >> FooServiceFactory no longer promises to provide a Foo service :-( >> >> Kind regards, >> >> Peter Kriens >> >> >>> On 20 Apr 2017, at 12:35, Timothy Ward wrote: >>> >>> DS isn’t intended to solve every single use case, rather to make common use >>> cases simple to write and understand. In this case what you want is more >>> advanced, and unlikely to make it into DS as a natively supported pattern. >>> Given that you’re already tied to the core OSGi API (ServiceFactory) then >>> registering the service programatically would still let DS help you with >>> config and service injection. >>> >>> >>> @Component( >>> // Do not let DS provide the service >>> service = {}, >>> configurationPolicy = ConfigurationPolicy.REQUIRE >>> ) >>> public class FooServiceFactory implements ServiceFactory { >>> >>> @Reference // provides FooBuilder instances that are pre-configured via OSGi >>> private FooBuilderFactory fooBuilderFactory; >>> >>> private ServiceRegistration reg; >>> >>> @Activate >>> void start(BundleContext ctx, Map props, Config config) { >>>reg = ctx.registerService(Foo.class.getName(), this, props); >>> } >>> >>> @Deactivate >>> void stop() { >>>reg.unregister(); >>> } >>> >>> @Override >>> public Foo getService() { >>> FooBuilder fooBuilder = fooBuilderFactory.builder(); >>> applyConfiguration(fooBuilder); >>> return fooBuilder.build(); >>> } >>> >>> private void applyConfiguration(FooBuilder fooBuilder) { >>> // apply OSGi configuration to FooBuilder object >>> } >>> >>> ... // ungetService omitted for brevity >>> >>> } >>> >>> >>> Regards, >>> >>> Tim >>> >>> On 20 Apr 2017, at 11:11, Julian Sedding wrote: Hi Timothy Thanks for your reply. Using delegation works, I currently use it to solve my use-case. However, compared to implementing a ServiceFactory, delegation adds some overhead: - delegation needs to be implemented, which is trivial, but noisy if there are lots of methods that need delegating - by delegating, my implementation becomes a "provider" of Foo, rather than a "consumer", making my bundle more susceptible to changes in Foo's API - also: delegation is not possible if Foo is a final class I brought up this topic in order to (a) confirm that my desired approach is indeed not possible at the moment and (b) to see if adding support for registering custom ServiceFactory implementations via DS could be a desirable enhancement for the spec. Regards Julian > On Thu, Apr 20, 2017 at 11:22 AM, Timothy Ward > wrote: > Have you not considered the following: > > > @Component(configurationPolicy = ConfigurationPolicy.REQUIRE, > scope = ServiceScope.BUNDLE) > public class FooImpl implements Foo { > > public @interface Config { > // Config definition in here > } > > @Reference > private FooBuilderFactory fooBuilderFactory; > > private Foo delegate; > > @Activate > void start(Config config) { >FooBuilder fooBuilder = fooBuilderFactory.builder(); >applyConfiguration(fooBuilder, config); >delegate = fooBuilder.build(); > } > > // Deactivation and Foo delegation methods go here > … > } > > Regards, > > Tim > >> On 20 Apr 2017, at 09:30, Julian Sedding wrote: >> >> Hi there >> >> I have been trying to implement a use-case, but I seem to be running >> into walls ;) (Disclaimer: I can see multiple ways to implement this, >> but would like to re-use the dependency injection and lazy >> instantiation of DS). >> >> My aim is to create configured service objects in the way that is >> normally achieved by using a DS factory component with >> configuration-policy require. >> >> The catch is that the implementation of the objects I want to >> configure and register as a service is not under my control and is >> instanciated via a builder obtained from a factory that is registered >> as an OSGi-service. Sounds a bit complicated, maybe it's clearer in >> code. >> >> @Component( >> service = Foo.class, >> configurationPolicy =
Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?
Peter - I assume that you mean that there will be no auto-generated osgi.service capability. Couldn't that be fixed with an additional annotation on the component type to add the Provide-Capability to the manifest? Tim Ward Sent from my iPhone > On 20 Apr 2017, at 12:38, Peter Krienswrote: > > But then you loose the DS dependency management on Foo … Since your > FooServiceFactory no longer promises to provide a Foo service :-( > > Kind regards, > >Peter Kriens > > >> On 20 Apr 2017, at 12:35, Timothy Ward wrote: >> >> DS isn’t intended to solve every single use case, rather to make common use >> cases simple to write and understand. In this case what you want is more >> advanced, and unlikely to make it into DS as a natively supported pattern. >> Given that you’re already tied to the core OSGi API (ServiceFactory) then >> registering the service programatically would still let DS help you with >> config and service injection. >> >> >> @Component( >> // Do not let DS provide the service >> service = {}, >> configurationPolicy = ConfigurationPolicy.REQUIRE >> ) >> public class FooServiceFactory implements ServiceFactory { >> >> @Reference // provides FooBuilder instances that are pre-configured via OSGi >> private FooBuilderFactory fooBuilderFactory; >> >> private ServiceRegistration reg; >> >> @Activate >> void start(BundleContext ctx, Map props, Config config) { >> reg = ctx.registerService(Foo.class.getName(), this, props); >> } >> >> @Deactivate >> void stop() { >> reg.unregister(); >> } >> >> @Override >> public Foo getService() { >> FooBuilder fooBuilder = fooBuilderFactory.builder(); >> applyConfiguration(fooBuilder); >> return fooBuilder.build(); >> } >> >> private void applyConfiguration(FooBuilder fooBuilder) { >> // apply OSGi configuration to FooBuilder object >> } >> >> ... // ungetService omitted for brevity >> >> } >> >> >> Regards, >> >> Tim >> >> >>> On 20 Apr 2017, at 11:11, Julian Sedding wrote: >>> >>> Hi Timothy >>> >>> Thanks for your reply. Using delegation works, I currently use it to >>> solve my use-case. >>> >>> However, compared to implementing a ServiceFactory, delegation adds >>> some overhead: >>> >>> - delegation needs to be implemented, which is trivial, but noisy if >>> there are lots of methods that need delegating >>> - by delegating, my implementation becomes a "provider" of Foo, rather >>> than a "consumer", making my bundle more susceptible to changes in >>> Foo's API >>> - also: delegation is not possible if Foo is a final class >>> >>> I brought up this topic in order to (a) confirm that my desired >>> approach is indeed not possible at the moment and (b) to see if adding >>> support for registering custom ServiceFactory implementations via DS >>> could be a desirable enhancement for the spec. >>> >>> Regards >>> Julian >>> >>> On Thu, Apr 20, 2017 at 11:22 AM, Timothy Ward wrote: Have you not considered the following: @Component(configurationPolicy = ConfigurationPolicy.REQUIRE, scope = ServiceScope.BUNDLE) public class FooImpl implements Foo { public @interface Config { // Config definition in here } @Reference private FooBuilderFactory fooBuilderFactory; private Foo delegate; @Activate void start(Config config) { FooBuilder fooBuilder = fooBuilderFactory.builder(); applyConfiguration(fooBuilder, config); delegate = fooBuilder.build(); } // Deactivation and Foo delegation methods go here … } Regards, Tim > On 20 Apr 2017, at 09:30, Julian Sedding wrote: > > Hi there > > I have been trying to implement a use-case, but I seem to be running > into walls ;) (Disclaimer: I can see multiple ways to implement this, > but would like to re-use the dependency injection and lazy > instantiation of DS). > > My aim is to create configured service objects in the way that is > normally achieved by using a DS factory component with > configuration-policy require. > > The catch is that the implementation of the objects I want to > configure and register as a service is not under my control and is > instanciated via a builder obtained from a factory that is registered > as an OSGi-service. Sounds a bit complicated, maybe it's clearer in > code. > > @Component( > service = Foo.class, > configurationPolicy = ConfigurationPolicy.REQUIRE > ) > public class FooServiceFactory implements ServiceFactory { > > @Reference // provides FooBuilder instances that are pre-configured via > OSGi > private FooBuilderFactory fooBuilderFactory; > > @Override > public Foo
Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?
But then you loose the DS dependency management on Foo … Since your FooServiceFactory no longer promises to provide a Foo service :-( Kind regards, Peter Kriens > On 20 Apr 2017, at 12:35, Timothy Wardwrote: > > DS isn’t intended to solve every single use case, rather to make common use > cases simple to write and understand. In this case what you want is more > advanced, and unlikely to make it into DS as a natively supported pattern. > Given that you’re already tied to the core OSGi API (ServiceFactory) then > registering the service programatically would still let DS help you with > config and service injection. > > > @Component( > // Do not let DS provide the service > service = {}, > configurationPolicy = ConfigurationPolicy.REQUIRE > ) > public class FooServiceFactory implements ServiceFactory { > > @Reference // provides FooBuilder instances that are pre-configured via OSGi > private FooBuilderFactory fooBuilderFactory; > > private ServiceRegistration reg; > > @Activate > void start(BundleContext ctx, Map props, Config config) { > reg = ctx.registerService(Foo.class.getName(), this, props); > } > > @Deactivate > void stop() { > reg.unregister(); > } > > @Override > public Foo getService() { > FooBuilder fooBuilder = fooBuilderFactory.builder(); > applyConfiguration(fooBuilder); > return fooBuilder.build(); > } > > private void applyConfiguration(FooBuilder fooBuilder) { > // apply OSGi configuration to FooBuilder object > } > > ... // ungetService omitted for brevity > > } > > > Regards, > > Tim > > >> On 20 Apr 2017, at 11:11, Julian Sedding wrote: >> >> Hi Timothy >> >> Thanks for your reply. Using delegation works, I currently use it to >> solve my use-case. >> >> However, compared to implementing a ServiceFactory, delegation adds >> some overhead: >> >> - delegation needs to be implemented, which is trivial, but noisy if >> there are lots of methods that need delegating >> - by delegating, my implementation becomes a "provider" of Foo, rather >> than a "consumer", making my bundle more susceptible to changes in >> Foo's API >> - also: delegation is not possible if Foo is a final class >> >> I brought up this topic in order to (a) confirm that my desired >> approach is indeed not possible at the moment and (b) to see if adding >> support for registering custom ServiceFactory implementations via DS >> could be a desirable enhancement for the spec. >> >> Regards >> Julian >> >> >> On Thu, Apr 20, 2017 at 11:22 AM, Timothy Ward wrote: >>> Have you not considered the following: >>> >>> >>> @Component(configurationPolicy = ConfigurationPolicy.REQUIRE, >>> scope = ServiceScope.BUNDLE) >>> public class FooImpl implements Foo { >>> >>> public @interface Config { >>> // Config definition in here >>> } >>> >>> @Reference >>> private FooBuilderFactory fooBuilderFactory; >>> >>> private Foo delegate; >>> >>> @Activate >>> void start(Config config) { >>> FooBuilder fooBuilder = fooBuilderFactory.builder(); >>> applyConfiguration(fooBuilder, config); >>> delegate = fooBuilder.build(); >>> } >>> >>> // Deactivation and Foo delegation methods go here >>> … >>> } >>> >>> Regards, >>> >>> Tim >>> On 20 Apr 2017, at 09:30, Julian Sedding wrote: Hi there I have been trying to implement a use-case, but I seem to be running into walls ;) (Disclaimer: I can see multiple ways to implement this, but would like to re-use the dependency injection and lazy instantiation of DS). My aim is to create configured service objects in the way that is normally achieved by using a DS factory component with configuration-policy require. The catch is that the implementation of the objects I want to configure and register as a service is not under my control and is instanciated via a builder obtained from a factory that is registered as an OSGi-service. Sounds a bit complicated, maybe it's clearer in code. @Component( service = Foo.class, configurationPolicy = ConfigurationPolicy.REQUIRE ) public class FooServiceFactory implements ServiceFactory { @Reference // provides FooBuilder instances that are pre-configured via OSGi private FooBuilderFactory fooBuilderFactory; @Override public Foo getService() { FooBuilder fooBuilder = fooBuilderFactory.builder(); applyConfiguration(fooBuilder); return fooBuilder.build(); } private void applyConfiguration(FooBuilder fooBuilder) { // apply OSGi configuration to FooBuilder object } ... // ungetService omitted for brevity } As far as I understand, this is not currently possible. The bnd
Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?
DS isn’t intended to solve every single use case, rather to make common use cases simple to write and understand. In this case what you want is more advanced, and unlikely to make it into DS as a natively supported pattern. Given that you’re already tied to the core OSGi API (ServiceFactory) then registering the service programatically would still let DS help you with config and service injection. @Component( // Do not let DS provide the service service = {}, configurationPolicy = ConfigurationPolicy.REQUIRE ) public class FooServiceFactory implements ServiceFactory { @Reference // provides FooBuilder instances that are pre-configured via OSGi private FooBuilderFactory fooBuilderFactory; private ServiceRegistration reg; @Activate void start(BundleContext ctx, Mapprops, Config config) { reg = ctx.registerService(Foo.class.getName(), this, props); } @Deactivate void stop() { reg.unregister(); } @Override public Foo getService() { FooBuilder fooBuilder = fooBuilderFactory.builder(); applyConfiguration(fooBuilder); return fooBuilder.build(); } private void applyConfiguration(FooBuilder fooBuilder) { // apply OSGi configuration to FooBuilder object } ... // ungetService omitted for brevity } Regards, Tim > On 20 Apr 2017, at 11:11, Julian Sedding wrote: > > Hi Timothy > > Thanks for your reply. Using delegation works, I currently use it to > solve my use-case. > > However, compared to implementing a ServiceFactory, delegation adds > some overhead: > > - delegation needs to be implemented, which is trivial, but noisy if > there are lots of methods that need delegating > - by delegating, my implementation becomes a "provider" of Foo, rather > than a "consumer", making my bundle more susceptible to changes in > Foo's API > - also: delegation is not possible if Foo is a final class > > I brought up this topic in order to (a) confirm that my desired > approach is indeed not possible at the moment and (b) to see if adding > support for registering custom ServiceFactory implementations via DS > could be a desirable enhancement for the spec. > > Regards > Julian > > > On Thu, Apr 20, 2017 at 11:22 AM, Timothy Ward wrote: >> Have you not considered the following: >> >> >> @Component(configurationPolicy = ConfigurationPolicy.REQUIRE, >>scope = ServiceScope.BUNDLE) >> public class FooImpl implements Foo { >> >> public @interface Config { >> // Config definition in here >> } >> >> @Reference >> private FooBuilderFactory fooBuilderFactory; >> >> private Foo delegate; >> >> @Activate >> void start(Config config) { >> FooBuilder fooBuilder = fooBuilderFactory.builder(); >> applyConfiguration(fooBuilder, config); >> delegate = fooBuilder.build(); >> } >> >> // Deactivation and Foo delegation methods go here >> … >> } >> >> Regards, >> >> Tim >> >>> On 20 Apr 2017, at 09:30, Julian Sedding wrote: >>> >>> Hi there >>> >>> I have been trying to implement a use-case, but I seem to be running >>> into walls ;) (Disclaimer: I can see multiple ways to implement this, >>> but would like to re-use the dependency injection and lazy >>> instantiation of DS). >>> >>> My aim is to create configured service objects in the way that is >>> normally achieved by using a DS factory component with >>> configuration-policy require. >>> >>> The catch is that the implementation of the objects I want to >>> configure and register as a service is not under my control and is >>> instanciated via a builder obtained from a factory that is registered >>> as an OSGi-service. Sounds a bit complicated, maybe it's clearer in >>> code. >>> >>> @Component( >>> service = Foo.class, >>> configurationPolicy = ConfigurationPolicy.REQUIRE >>> ) >>> public class FooServiceFactory implements ServiceFactory { >>> >>> @Reference // provides FooBuilder instances that are pre-configured via >>> OSGi >>> private FooBuilderFactory fooBuilderFactory; >>> >>> @Override >>> public Foo getService() { >>> FooBuilder fooBuilder = fooBuilderFactory.builder(); >>> applyConfiguration(fooBuilder); >>> return fooBuilder.build(); >>> } >>> >>> private void applyConfiguration(FooBuilder fooBuilder) { >>> // apply OSGi configuration to FooBuilder object >>> } >>> >>> ... // ungetService omitted for brevity >>> >>> } >>> >>> As far as I understand, this is not currently possible. The bnd tool >>> shouts at the mismatch between the "service" attribute (Foo.class) and >>> the ServiceFactory interface and refuses to generate the SCR XML. With >>> a manually crafted XML, Apache Felix SCR ends up throwing exceptions. >>> And most likely both implementations are correct, as I could not find >>> anything supporting my use-case in the spec. >>> >>> Can anyone on this list please confirm
Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?
Hi Timothy Thanks for your reply. Using delegation works, I currently use it to solve my use-case. However, compared to implementing a ServiceFactory, delegation adds some overhead: - delegation needs to be implemented, which is trivial, but noisy if there are lots of methods that need delegating - by delegating, my implementation becomes a "provider" of Foo, rather than a "consumer", making my bundle more susceptible to changes in Foo's API - also: delegation is not possible if Foo is a final class I brought up this topic in order to (a) confirm that my desired approach is indeed not possible at the moment and (b) to see if adding support for registering custom ServiceFactory implementations via DS could be a desirable enhancement for the spec. Regards Julian On Thu, Apr 20, 2017 at 11:22 AM, Timothy Wardwrote: > Have you not considered the following: > > > @Component(configurationPolicy = ConfigurationPolicy.REQUIRE, > scope = ServiceScope.BUNDLE) > public class FooImpl implements Foo { > >public @interface Config { > // Config definition in here >} > >@Reference >private FooBuilderFactory fooBuilderFactory; > >private Foo delegate; > >@Activate >void start(Config config) { >FooBuilder fooBuilder = fooBuilderFactory.builder(); >applyConfiguration(fooBuilder, config); >delegate = fooBuilder.build(); >} > >// Deactivation and Foo delegation methods go here >… > } > > Regards, > > Tim > >> On 20 Apr 2017, at 09:30, Julian Sedding wrote: >> >> Hi there >> >> I have been trying to implement a use-case, but I seem to be running >> into walls ;) (Disclaimer: I can see multiple ways to implement this, >> but would like to re-use the dependency injection and lazy >> instantiation of DS). >> >> My aim is to create configured service objects in the way that is >> normally achieved by using a DS factory component with >> configuration-policy require. >> >> The catch is that the implementation of the objects I want to >> configure and register as a service is not under my control and is >> instanciated via a builder obtained from a factory that is registered >> as an OSGi-service. Sounds a bit complicated, maybe it's clearer in >> code. >> >> @Component( >>service = Foo.class, >>configurationPolicy = ConfigurationPolicy.REQUIRE >> ) >> public class FooServiceFactory implements ServiceFactory { >> >>@Reference // provides FooBuilder instances that are pre-configured via >> OSGi >>private FooBuilderFactory fooBuilderFactory; >> >>@Override >>public Foo getService() { >>FooBuilder fooBuilder = fooBuilderFactory.builder(); >>applyConfiguration(fooBuilder); >>return fooBuilder.build(); >>} >> >>private void applyConfiguration(FooBuilder fooBuilder) { >>// apply OSGi configuration to FooBuilder object >>} >> >>... // ungetService omitted for brevity >> >> } >> >> As far as I understand, this is not currently possible. The bnd tool >> shouts at the mismatch between the "service" attribute (Foo.class) and >> the ServiceFactory interface and refuses to generate the SCR XML. With >> a manually crafted XML, Apache Felix SCR ends up throwing exceptions. >> And most likely both implementations are correct, as I could not find >> anything supporting my use-case in the spec. >> >> Can anyone on this list please confirm that this is not (currently) possible? >> >> I think this use-case is relatively generic. It has two preconditions: >> >> - the implementation of the service object (e.g. Foo) is out of my >> control and can therefore not be enhanced with OSGi-specifics >> - in order to be able to create the service object, dependencies on >> other services are required >> >> Does this sound like a possible addition to the Declarative Services >> specification? >> >> Regards >> Julian >> >> PS: For those curious on how this could be implemented today. One way >> to implement this is to register the ServiceFactory (lazily) by hand. >> Provided Foo is not a final class, another way is to create a wrapper >> for Foo that delegates all calls to a "real" Foo instance. The >> FooWrapper implementation is then under my control and can be enhanced >> with DS annotations etc. >> ___ >> OSGi Developer Mail List >> osgi-dev@mail.osgi.org >> https://mail.osgi.org/mailman/listinfo/osgi-dev > > ___ > OSGi Developer Mail List > osgi-dev@mail.osgi.org > https://mail.osgi.org/mailman/listinfo/osgi-dev ___ OSGi Developer Mail List osgi-dev@mail.osgi.org https://mail.osgi.org/mailman/listinfo/osgi-dev
Re: [osgi-dev] Allow registering a (Prototype)ServiceFactory via DS?
Have you not considered the following: @Component(configurationPolicy = ConfigurationPolicy.REQUIRE, scope = ServiceScope.BUNDLE) public class FooImpl implements Foo { public @interface Config { // Config definition in here } @Reference private FooBuilderFactory fooBuilderFactory; private Foo delegate; @Activate void start(Config config) { FooBuilder fooBuilder = fooBuilderFactory.builder(); applyConfiguration(fooBuilder, config); delegate = fooBuilder.build(); } // Deactivation and Foo delegation methods go here … } Regards, Tim > On 20 Apr 2017, at 09:30, Julian Seddingwrote: > > Hi there > > I have been trying to implement a use-case, but I seem to be running > into walls ;) (Disclaimer: I can see multiple ways to implement this, > but would like to re-use the dependency injection and lazy > instantiation of DS). > > My aim is to create configured service objects in the way that is > normally achieved by using a DS factory component with > configuration-policy require. > > The catch is that the implementation of the objects I want to > configure and register as a service is not under my control and is > instanciated via a builder obtained from a factory that is registered > as an OSGi-service. Sounds a bit complicated, maybe it's clearer in > code. > > @Component( >service = Foo.class, >configurationPolicy = ConfigurationPolicy.REQUIRE > ) > public class FooServiceFactory implements ServiceFactory { > >@Reference // provides FooBuilder instances that are pre-configured via > OSGi >private FooBuilderFactory fooBuilderFactory; > >@Override >public Foo getService() { >FooBuilder fooBuilder = fooBuilderFactory.builder(); >applyConfiguration(fooBuilder); >return fooBuilder.build(); >} > >private void applyConfiguration(FooBuilder fooBuilder) { >// apply OSGi configuration to FooBuilder object >} > >... // ungetService omitted for brevity > > } > > As far as I understand, this is not currently possible. The bnd tool > shouts at the mismatch between the "service" attribute (Foo.class) and > the ServiceFactory interface and refuses to generate the SCR XML. With > a manually crafted XML, Apache Felix SCR ends up throwing exceptions. > And most likely both implementations are correct, as I could not find > anything supporting my use-case in the spec. > > Can anyone on this list please confirm that this is not (currently) possible? > > I think this use-case is relatively generic. It has two preconditions: > > - the implementation of the service object (e.g. Foo) is out of my > control and can therefore not be enhanced with OSGi-specifics > - in order to be able to create the service object, dependencies on > other services are required > > Does this sound like a possible addition to the Declarative Services > specification? > > Regards > Julian > > PS: For those curious on how this could be implemented today. One way > to implement this is to register the ServiceFactory (lazily) by hand. > Provided Foo is not a final class, another way is to create a wrapper > for Foo that delegates all calls to a "real" Foo instance. The > FooWrapper implementation is then under my control and can be enhanced > with DS annotations etc. > ___ > OSGi Developer Mail List > osgi-dev@mail.osgi.org > https://mail.osgi.org/mailman/listinfo/osgi-dev ___ OSGi Developer Mail List osgi-dev@mail.osgi.org https://mail.osgi.org/mailman/listinfo/osgi-dev