Re: [sisu-users] mixing injection and non-injection

[Benson Margulies <benson@xxxxxxxxxxxxx>]

This turns out to be a 100% Guice issue; I learned about @Assisted and
now I've got something presentable.

On Sat, Feb 1, 2014 at 3:25 PM, Benson Margulies <benson@xxxxxxxxxxxxx> wrote:
> This may be more of a Guice, or even generic DI, issue, but I'll ask
> in case there's a sisu-specific pattern.
>
> While initializing a complex system, the code needs at some place to
> create N items. Each item needs some facts which are dynamically
> determined. It also needs some things which are available for
> injection.
>
> I could code the constructor to accept the dynamic resources and call
> the injector to inject the rest.
>
> Or I could set up a Provider over the objects, or call the injector to
> make them, but code them so that they are not completely constructed
> until I pass in the dynamic data.
>
> Or, I can leave these items out of the DI system, and just code the
> thing that creates them to have everything they need available via
> injection and just pass it in via constructor.
>
> The case in hand is initializing a sequence of worker threads, one for
> each of a variable collection of tasks. There's an injected collection
> of the overall application that names the tasks. For each task, the
> code has to create a thread, and hand it the identity of its task.
>
>      @Inject Collection<Task> tasks;
>      @Inject Provider<TaskRunner> provider;
>
>
>      for (Task task : tasks) {
>        // I wish I could ...
>       thisRunner =  provider.get(task); // instead of provider.get()
>        // OR...
>       thisRunner = provider.get(); // or injector.....
>       thisRunnset.setTask(task);
>       thisRunner.initialize(); // yuck.
>       // OR ...
>       thisRunner = new TaskRunner(task);
>      injector.inject...(thisRunner);
>      thisRunner.initialize(); // yuck
>     }
>
> Is there a better way to approach this.