public interface ProviderWithExtensionVisitor<T> extends Provider<T>
When an extension binds a provider instance, the provider can implement this interface to
allow users using the Binding.acceptTargetVisitor(BindingTargetVisitor)
method to visit a
custom visitor designed for that extension. A typical implementation within the extension would
look like
<V, B> V acceptExtensionVisitor(BindingTargetVisitor<B, V> visitor, ProviderInstanceBinding<? extends B> binding) { if(visitor instanceof MyCustomExtensionVisitor) { return ((MyCustomExtensionVisitor<B, V>)visitor).visitCustomExtension(customProperties, binding); } else { return visitor.visit(binding); } }'MyCustomExtensionVisitor' in the example above would be an interface the extension provides that users can implement in order to be notified of custom extension information. These visitor interfaces must extend from BindingTargetVisitor.
Modifier and Type | Method and Description |
---|---|
<B,V> V |
acceptExtensionVisitor(BindingTargetVisitor<B,V> visitor,
ProviderInstanceBinding<? extends B> binding)
Instructs the extension determine if the visitor is an instance of a custom extension visitor,
and if so, visit it using that method.
|
<B,V> V acceptExtensionVisitor(BindingTargetVisitor<B,V> visitor, ProviderInstanceBinding<? extends B> binding)
Due to issues with generics, the type parameters of this method do not relate to the type of the provider. In practice, the 'B' type will always be a supertype of 'T'.
Copyright © 2006–2020 Google, Inc.. All rights reserved.