What Are the Advantages of Using DSPs?
In the example in
What Does a DSP Look Like?, the DSP invokes a service and displays its results. You could accomplish the same thing by invoking the service directly from a browser and applying an output template to the result. However, DSPs have several advantages over directly invoking a service with a URL:
They conceal the INVOKE mechanism and the name of the service from the user.
They give you the flexibility to change the name of a service or replace one service with another without changing the way in which the end user invokes the service. (The user always invokes the same DSP, whose contents you can change as needed.)
They can easily be updated and extended.
They allow you to execute multiple services via a single request.
They allow you to conditionally execute a service based on run-time input. For example, you might build a DSP that actually contains several different HTML pages, and use the
%switch% tag to select among them.