Is PRISM a form of SOA?

Is PRISM a form of Service Oriented Archetectu开发者_Go百科re?

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From Wikipedia:

"Service-oriented architecture (SOA) is a flexible set of design principles used during the phases of systems development and integration in computing. A system based on a SOA will package functionality as a suite of interoperable services that can be used within multiple separate systems from several business domains."

(Preemptive snarky comment: I know, Wikipedia. Sometimes, its just the easiest thing to use as a resource.)

I think the key distinction here is that a SOA implies interaction between discrete systems over some medium. That interaction isn't necessarily defined, but the implicit assumption is that the systems are independent and use a communication mechanism to obtain services.

As a framework, Prism requires you to not be independent, i.e., it does not expose its services through some external interaction mechanism. You can't use SOAP or XML to subscribe or receive an event through IEventAggregator. That isn't Prism's purpose: it's used to build applications that may, in turn, be SOA (or not).

That being said, it obviously uses principles inherent in SOA through its usage of dependency injection containers. The fact that, in your application, you can ask for a Prism service (IRegionManager, IEventAggregator, etc.) through the container without actually worrying about the construction of the service yourself implies a service-oriented design. Of course, you do construct the service - but it happens "under the hood" in the bootstrapper. But you do have to be tightly coupled to Prism in order to get the service, and you're only going to get the service through code. Not over any medium.

(Although, there are people who have looked at exposing those services over mediums, such as PRISM and WCF - Do they play nice?, wherein IEventAggregator is exposed over WCF)