Introducing a new service type

Every service belongs to a given service type. A service type is represented by a key, just like an extension key. In the examples above there were mentions of the "auth" and "metaExtract" service types.

Each service type will implement its own API corresponding to the task it is designed to handle. For example the "auth" service type requires the two methods getUser() and authUser(). If you introduce a new service type you should think well about its API before starting development. Ideally you should discuss with other developers. Services are meant to be reusable. A badly designed service that is used only once is a failed service.

You should plan to provide an interface and/or base class for your new service type. It is then easier to develop services based on this type as you can start by extending the base class. You should also provide a documentation, that describes the API. It should be clear to other developers what each method of the API is supposed to do.