virtual-provider-injection-dsl.md

Virtual Provider Injection DSL

You can inject automatic object providers by using the provider injection DSL namespace. This will inject a WireBox provider class (wirebox.system.ioc.Provider) that follows our Provider pattern with one method on it: get() that will provide you with the requested mapped object.

The difference between custom providers here is that WireBox will create a virtual provider object for you dynamically at runtime, configure it to retrieve a specific type of mapping and then use that for you. The provider namespace will take everything after it and evaluate it as either a named mapping or a full injection DSL string.

For example, inject="provider:MyService" will inject a provider of MyService objects, so it will look for a MyService ID in the binder. However, you can also get mega funky and do this: inject="provider:logbox:logger:{this}" and WireBox will create a provider of logbox:logger:{this}.

Caution Remember that the value of the provider can be a simple ID or a full injection DSL.

// use the provider DSL namespace on a property
property name="searchCriteria" inject="provider:requestCriteria";

// use the provider DSL namespace on a constructor argument
function init(coolObjectProvider inject="provider:HardToConstructObject"){
    variables.coolObjectProvider = arguments.coolObjectProvider;
    return this;
}

// To use it
searchCriteria.get().getCriteria();
coolObjectProvider.get().executeSomeMethod();

That's it! You basically use the provider:{mapping} injection DSL to tell a property, setter or argument that you want a provider object instead of the real deal. This will allow you to delay construction of such an object or avoid the nasty pitfall of scope widening injection.