Advanced services

The services concepts covered so far should address a lot of typical use cases, but there are a few additional features and concepts that might come in handy in certain special scenarios. We'll look at a few such concepts in this section.

Supporting singleton and factory providers

Suppose your service instances cannot be created simply by a constructor. What if you need to reuse instances, maybe to have a singleton provider instance? Or maybe execute some logic whenever a new service instance is created? There is a handy feature of services that lets you create factory methods to get service instances. All you need to do is add a method with the name provide() in your provider classes. The method...