The provider could be a solution, but the problem is I don't have information on the injectee (in my case: the attached annotations)... So, I can not control the injection as I wish :-/
2010/1/19 Marcos Alcantara <[email protected]> > "I'd like that Guice call me when it tries to inject, and so I will return > the "better" instance. " > > Isn´t this the provider role? > > You can extend the Provider class too so you can inject other "context" > objects into it and decide which instance would be best for the moment. > > =) > > Hope this can help you. > > Best regards, > > Marcos Alcantara > > On Tue, Jan 19, 2010 at 11:56 AM, Anthony MULLER <[email protected] > > wrote: > >> Thanks Fred! But my bindings are "modular"... I don't know them before >> startup... >> >> In the example, imagine the injectee must be the instance with the time >> the closest of injection time. Or, if no "@Timed" is provided, the default >> implementation must be injected. >> >> // Example >> public class MaClasse { >> @Inject // Default injection >> private ISomething something; >> >> @Inject @Timed // Timed injection >> private ISomething something; >> } >> >> Bindings : >> ISomething --> DefaultSomethingImpl // Default >> >> "Contributors" can provided bindings like: >> ISomething @Named("8:15") --> SomethingMorningImpl // Optional >> ISomething @Named("12:30") --> SomethingMiddayImpl // Optional >> ISomething @Named("20:55") --> SomethingEveningImpl // Optional >> >> As you see, I don't know the list in advance... >> >> The provider could be a solution, but the problem is I don't have >> information on the injectee (in my case: the attached annotations)... So, I >> can not control the injection as I wish :-/ >> >> Maybe it is possible to do what I wish by using Guice 2.0 and its SPI? >> >> Regards, >> Anthony >> >> >> 2010/1/19 Fred Faber <[email protected]> >> >>> Anton's suggestion should do the trick: >>> >>> class ISomethingProvider implements Provider<ISomething> { >>> >>> @Inject @ReportsTimeOfDay >>> TimeOfDayReporter timeOfDayReporter; >>> >>> @Inject @Name("morning") >>> Provider<ISomething> somethingMorningProvider; >>> >>> @Inject @Name("midday") >>> Provider<ISomething> somethingMiddayProvider; >>> >>> @Inject @Name("evening") >>> Provider<ISomething> somethingEveningProvider; >>> >>> @Override >>> public ISomething get() { >>> TimeOfDay timeOfDay = timeOfDayReporter.getTimeOfDay(); >>> if (timeOfDay.isMorning()) { >>> return somethingMorningProvider.get(); >>> } else if (....) { >>> .... >>> } >>> } >>> } >>> >>> >>> and then: >>> >>> bind(ISomething.class) >>> .toProvider(ISomethingProvider.class); >>> >>> >>> * * * >>> >>> "injection context" is a vague and simultaneous powerful concept, which >>> is different from application to application, and even injection to >>> injection. the provider construct allows flexible definitions of this >>> context to suit each setting. >>> >>> -Fred >>> >>> On Tue, Jan 19, 2010 at 9:18 AM, Anthony MULLER < >>> [email protected]> wrote: >>> >>>> Ok! >>>> >>>> Imagine I have several bindings for ISomething : >>>> >>>> ISomething @Named("morning") --> SomethingMorningImpl >>>> ISomething @Named("midday") --> SomethingMiddayImpl >>>> ISomething @Named("evening") --> SomethingEveningImpl >>>> >>>> At runtime, I know what time is it and I wish that the proper instance >>>> is injected according the time: >>>> >>>> public class MaClasse { >>>> @Inject >>>> @Timed >>>> private ISomething something; >>>> } >>>> >>>> I'd like that Guice call me when it tries to inject, and so I will >>>> return the "better" instance. >>>> >>>> As you see, the framework is not able to decide alone in that case. But >>>> if it is possible to plug behaviour at injection time, this case can be >>>> resolved. >>>> >>>> Hoper I'm clearer :-p >>>> >>>> Regards, >>>> Anthony >>>> >>>> >>>> 2010/1/19 Fred <[email protected]> >>>> >>>>> Could you please give an example? I'm having a hard time interpreting >>>>> >>>>> what you mean. >>>>> >>>>> On Jan 19, 8:15 am, Anthony MULLER <[email protected]> wrote: >>>>> > Hello, >>>>> > >>>>> > I can't remember... I work with Guice 1.0. >>>>> > >>>>> > Is is possible to take the hand when it is written: >>>>> > >>>>> > public class MaClasse { >>>>> > >>>>> > @Inject >>>>> > private ISomething something; >>>>> > >>>>> > } >>>>> > >>>>> > I'd like to write a specific resolution, to choose the "best" >>>>> binding.... >>>>> > >>>>> > Thanks, >>>>> > Anthony >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "google-guice" group. >>>>> To post to this group, send email to [email protected]. >>>>> To unsubscribe from this group, send email to >>>>> [email protected]<google-guice%[email protected]> >>>>> . >>>>> For more options, visit this group at >>>>> http://groups.google.com/group/google-guice?hl=en. >>>>> >>>>> >>>>> >>>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "google-guice" group. >>>> To post to this group, send email to [email protected]. >>>> To unsubscribe from this group, send email to >>>> [email protected]<google-guice%[email protected]> >>>> . >>>> For more options, visit this group at >>>> http://groups.google.com/group/google-guice?hl=en. >>>> >>>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "google-guice" group. >>> To post to this group, send email to [email protected]. >>> To unsubscribe from this group, send email to >>> [email protected]<google-guice%[email protected]> >>> . >>> For more options, visit this group at >>> http://groups.google.com/group/google-guice?hl=en. >>> >>> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "google-guice" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]<google-guice%[email protected]> >> . >> For more options, visit this group at >> http://groups.google.com/group/google-guice?hl=en. >> >> > > -- > You received this message because you are subscribed to the Google Groups > "google-guice" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<google-guice%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/google-guice?hl=en. > >--
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