That's excellent
On Wed, Apr 2, 2014 at 1:33 AM, Sam Berlin <[email protected]> wrote: > Ever wanted to: > 1) Set default binding in a library or framework that users can change? > 2) Inject something into a library or framework that isn't required, but > would be better if a user could set it? > 3) Inject an optional value into a constructor? > > OptionalBinder lets you do that. Christian just pushed out some of our > recent internal changes, including the introduction of OptionalBinder to > the multibindings extension. > > Some example usage: > > 1) Setting a default binding that a user can override: > Library: *OptionalBinder.newOptionalBinder(binder(), Foo.class)* > * .setDefault().to(DefaultFoo.class);* > At this point, code can inject '*Foo*' (or *Optional<Foo>)*, and will > get a *DefaultFoo.* > > User: *OptionalBinder.newOptionalBinder(binder(), Foo.class)* > * .setBinding().to(CustomFoo.class);* > Once a user calls setBinding(), injections of *Foo* (or > *Optional<Foo>)* will start providing *CustomFoo* instead. > > 2) Setting a binding that isn't required (e.g, no default value), but a > user can supply. > Library: *OptionalBinder.newOptionalBinder(binder(), Foo.class);* > At this point, code *can't* inject *Foo* -- it will fail saying the > binding isn't supplied. Code *can* (and should) inject *Optional<Foo>*, > though, and the optional will be absent. > > User: *OptionalBinder.newOptionalBinder(binder(), Foo.class)* > * .setBinding().to(CustomFoo.class);* > Once a user calls setBinding(), *Optional<Foo>* will be present and > supply the *CustomFoo*. Also, *Foo* can be directly injected now > (although only user could should do that, since the user code is the only > part that guarantees the binding will be there -- library code should still > inject the* Optional<Foo>*). > > Please report back if you have any issues or suggestions for improvement. > > Thanks! > > sam > > -- > You received this message because you are subscribed to the Google Groups > "google-guice" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/google-guice. > For more options, visit https://groups.google.com/d/optout. > -- Filipe Sousa -- You received this message because you are subscribed to the Google Groups "google-guice" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/google-guice. For more options, visit https://groups.google.com/d/optout.
