In 2008, the Finite State Logic option for code generation was introduced in the Web Service Generator framework. The design utilizing a simple Finite state logic engine to address the complexities of screen-based applications is based on literally decades of experience in implementing screen integration solutions.
Depending on the design-time decisions and properties set for screens involved in a web service, the code generator will emit one or more state handlers for each TaskScreen defined for each Task. The state handlers are each based on a recognized state that a screen can be in at any given time, depending on that screen's role in the task (TaskIOType) as well as the NavigationType defined for the screen.
By understanding the behavior of each type of state handler and how the generator decides to include a particular state handler, you gain full control over how your web services behave.
Note that the class and module design of the generated solution make it very simple for a developer to override any of the generated state handlers, and replace functionality and/or insert additional state handlers into the work flow.
Following are descriptions of each state handler. In these, the topic name is the same name as a generated handler, with "ScreenID" replaced by the actual screen being processed at the time the handler is run.
Here are the potential state handlers that can be generated for each screen. For each handler, the properties and definitions that control generation are indicated
