Declarative and nested flows

Up to now, we have seen the implicit flow in action. Implicit flow is very straightforward for the simplest flow, which performs like a basic web wizard where the user is able to navigate linearly, going forward and backward. It can also use random access to navigate to pages.

If we want to take Faces Flow further, then we must delve into the XML flow definition, but first let us define some terms.

The flow node terminology

The fundamental technology being inspired by workflow and BPM, the Faces Flow specification declares different types of nodes which are given in the following table:

Node Type Name	Description
View	Represents any type of application JSF view
Method Call	Represents a method invocation in the flow graph through Expression Language (EL)
Flow Call	Represents an invocation of another flow with outbound (call) and (return) inbound parameters
Flow Return	Represents a return to the calling flow
Switch	Represents navigation selection...