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The Core Services of WF

In addition to designer tools, activities, and a runtime engine, WF provides a set of out-of-the-box

services that complete the overall framework of a workflow-enabled application. Using these serv-

ices we can “inherit” a good deal of commonly required WF infrastructure, rather than having to

commit time and resources to build this infrastructure by hand. Table 26-1 documents the intrinsic

services baked into the WF API.

Collectively, the four intrinsic services seen in Table 26-1 are termed the 

core services. The WF

APIs provide default implementations of each of these services, two of which are mandatory (sched-

uling and transactions), while tracking and persistence services are optional and not registered with

the runtime by default. While the .NET base class libraries do provide types that support each core

service, you are able to exchange them with your own custom implementations. Thus, if you wish to

customize the way in which a long-running workflow should be persisted, you can do so. As well, if

you wish to extend the basic functionality of a service with new functionality, it is possible to do so.

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Table 26-1.

Intrinsic Services of WF