Child Injectors

Welcome to the world of hierarchical dependency injection. We had the ability before to add a parent injector to WireBox, but you can not only add a parent, but also many children to the hierarchy.
Every injector has the capability to store an ordered collection (
ordered struct
) of child injectors via the childInjectors
property. Child injectors are used internally in many instances to provide a hierarchical approach to DI where instances can be searched for locally, in the parent and in the children. Here are some of the new methods to assist with child injectors:
hasChildInjector( name )
- Verify if a child injector has been registeredregisterChildInjector( name, child )
- Register a child injector by nameremoveChildInjector( name )
- Remove a child injector by namegetChildInjector( name )
- Get a child injector by namegetChildInjectors()
- Get all the child injectors registeredgetChildInjectorNames()
- Get an array of all the registered child injectors
getInstance()
- The
getInstance()
method has aninjector
argument so you can EXPLICITLY request an instance from a child injector by namegetInstance( name : "service", injector : "childInjector" )
- Apart from the explicit lookup it can also do implicit hierarchical lookups using the following order:
- Locally
- Parent
- All Children (in order of registration)
containsInstance( name )
- This method now also searches in the child collection for the specificname
instance. The lookup searches in the following order:- 1.Locally
- 2.Parent
- 3.Children (in order of registration)
shutdown()
- The shutdown method has been enhanced to issue shutdown method calls to all child injectors registered.
The
getInstance()
has been modified to have an injector
argument that you can use to specifically ask for an instance from that child injector. If the child injector has not been registered you will get a InvalidChildInjector
Exception.getInstance( name: "CategoryService", injector : "ChildInjector" )
The following is the DSL you can use to explicitly target a child injector for a dependency. You will prefix it with
wirebox:child:{name}
and the name of the injector:// Use the property name as the instance name
property name="categoryService" inject="wirebox:child:childInjector"
// Use a specific instance name
property name="categoryService" inject="wirebox:child:childInjector:CategoryService"
// Use any DSL
property name="categoryService" inject="wirebox:child:childInjector:{DSL}"
Last modified 10mo ago