Thanks for your reply Richard. I am using a lifecycle controller already to make it possible to enable/disable my services via a GUI. I'll see if I can use it for this purpose.
I've also tried the following approach: Keep track of all possible services that expose the interface I'm intererested in as follows: @Requires(optional = true) private IOrchestrationProcessor[] mProcessors; In runtime, when my service is being activated (prior to creating the camel route) I check to see if all required processors exist, if not I throw an exception. Unfortunately I have no control of in what order the services will be activated so its hard to ever get the camel route created this way. A lot of the time a "required" services is activated a bit later. /Bengt 2013/10/2 Richard S. Hall <[email protected]> > > On 10/2/13 08:42 , Bengt Rodehav wrote: > >> I'm creating a dynamic processing component using iPOJO and Camel. The >> idea >> is to dynamically specify (via config admin) a number of processor id's. >> In >> runtime I want to find the matching processors (the processors are Camel >> processors published as OSGi services) with the correct id. >> >> E g if I specify a list of services to {A,B} (FileInstall recognizes this >> as a list). I want to require those services in order for my iPojo >> instance >> to become valid. It was much harder than I thought. >> >> I've tried something like: >> >> @Property(name = "processors", mandatory = false, value = "") >> public void setProcessors(String[] theProcessorIds) { >> mProcessorIds = theProcessorIds; >> updateProcessorFilter(); >> } >> >> @Requires >> private Processor[] mProcessors; >> >> The idea is that whenever the configuration property "processors" is >> updated, I dynamically update the ldap filter on the dependency >> mProcessors. I've used this approach before and it has worked when using a >> single dependency (not an array). >> >> The problem is that I want to specifically require each specified >> processor. In the example above, I require one processor with id=A AND one >> processor with id=B. It's not enough with anyone of them since I want to >> invoke them one after another. >> >> Can I use a filter for this? I've been thinking of something like this: >> >> (|(processorId=A)(processorId=**B)) >> >> This would match both my processors but if one of them were missing my >> instance would still become valid which I don't want. >> > > I don't think there is anyway to do what you want. This is essentially an > "N cardinality" requirement, where you want to say that you require > specifically N of something. Such requirements had been discussed over the > years for Service Binder, Declarative Services, etc., but we could never > agree on their usefulness or how to do them, so we just left it as it is > now (i.e., optional, at least one...). > > Other than adding some sort of threshold to service dependencies, I don't > see this happening. You could potentially create an iPOJO lifecycle > controller that would keep your component invalid until it matched the > required number of services (if you can get this information in the > handler)...or perhaps write/extend the service dependency handler. > > -> richard > > >> /Bengt >> >> > > ------------------------------**------------------------------**--------- > To unsubscribe, e-mail: > users-unsubscribe@felix.**apache.org<[email protected]> > For additional commands, e-mail: [email protected] > >
