Yeah, I read your post again after I sent that. You weren't necessarily saying that it was a DI-only trick. I do agree with you that it's the way to go. The Null Object Pattern would be perfect for this situation (I thought the exact same thing when I read the question).
On Tue, Nov 24, 2009 at 7:59 AM, Loritsch, Berin C. <berin.lorit...@gd-ais.com> wrote: > Understood. Just introducing it as a possibility. > > -----Original Message----- > From: James Carman [mailto:jcar...@carmanconsulting.com] > Sent: Monday, November 23, 2009 3:40 PM > To: users@wicket.apache.org > Subject: Re: Can @SpringBeans be optional? > > That's not a dependency injection thing. It's a "design pattern" > called the "Null Object" pattern. > > On Mon, Nov 23, 2009 at 12:38 PM, Loritsch, Berin C. > <berin.lorit...@gd-ais.com> wrote: >> Technically speaking from the Dependency Injection koolaid doctrine, the >> best way to solve the problem is to have a "null" implementation of your >> service that does nothing. The code you are writing doesn't have to >> have complex if/else logic as it's able to assume the service is always >> there. The null implementation is wired in for the app that doesn't use >> it. >> >> Alternatively, create your accessor (getRememberMeService()) in the >> session that will access the ApplicationContext itself. It will >> determine if the bean exists or not and return the appropriate value. >> Since it allows for lazy initialization, it also addresses any issues >> from the ApplicationContext not being set up in time during unit >> testing. >> >> -----Original Message----- >> From: Anthony DePalma [mailto:fatef...@gmail.com] >> Sent: Monday, November 23, 2009 6:47 AM >> To: users@wicket.apache.org >> Subject: Can @SpringBeans be optional? >> >> Often with spring I give some of my services extra features if they are >> configured in the xml for it, but otherwise if they are null they are >> simply >> ignored. I'm running into an issue with my websession, that one of my >> apps >> can use the RememberMeService but another cannot. However, I'd like to >> have >> one abstractwebsession they can share, but unfortunately I'll get an >> exception when starting the app without the rememberMeService defined in >> the >> xml. It wouldn't make sense to define one to satisfy the error. >> >> The only solution I had so far was to inject it into the application >> class, >> where i can do so without @springbeans and thus a service can be null, >> but >> is there any way I can configure springbeans to not throw an error on >> startup for optional services? >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org >> For additional commands, e-mail: users-h...@wicket.apache.org >> >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org > For additional commands, e-mail: users-h...@wicket.apache.org > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org > For additional commands, e-mail: users-h...@wicket.apache.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org For additional commands, e-mail: users-h...@wicket.apache.org
