Rule Input

Rule inputs are used to:

• pass data down and up interfaces
• pass data into and out of a process model
• pass inputs to expression rules

Without rule inputs, you will not be able to save data from your interface into process variables. When creating the user input task, you will assign a rule input to an action class parameter. We can pass values into this ACP and save the ACP to a process variable. 

Without rule inputs, you will not be able to have multiple nested interfaces using the same data. Nor can you pass parameters to your expression rules.

For example...

this parent rule:

load(
  local!parentVar1: 5,
  local!parentVar2: 10,
  { 
    rule!JXI_childRule(
      inputVar1: local!parentVar1,
      inputVar2: local!parentVar2
    ),
    a!textField(
      label: "Directly accessing parentVar2 on the parent form: ",
      value: local!parentVar2,
      readOnly: true
    ),
    a!textField(
      label: "Calling an expression rule with a rule input: ",
      value: rule!JXI_expressionRuleRI(
        expressionRuleInput: local!parentVar2
      ),
      readOnly: true
    )
  }
)

calls this child rule, JXI_childRule:

{
  a!textField(
    readOnly: true,
    label: "Input Variable One: ",
    value: ri!inputVar1
  ),
  a!textField(
    readOnly: true,
    label: "Input Variable Two: ",
    value: ri!inputVar2
  ),
  a!buttonArrayLayout(
    align: "START",
    buttons: a!buttonWidget(
      label: "DOUBLE VAR 2",
      saveInto: a!save(ri!inputVar2, 2*ri!inputVar2)
    )
  )
}

and this expression rule, JXI_expressionRuleRI:

factdouble(ri!expressionRuleInput)

 

Let me know if you have questions on any of this. Hope it helps.

 

Some doc links:

https://docs.appian.com/suite/help/17.1/Interface_Designer.html#-manage-interface-inputs

https://docs.appian.com/suite/help/18.3/Expression_Rules.html#overview 

https://docs.appian.com/suite/help/18.3/Process_Modeling_Tutorial.html#add-an-approval-step-with-a-user-input-node 

Rule inputs also simplify the logic. Reduced the number of lines of code for an object. And able to reuse the same code over and over again.

The main advantage of rule input is that you can easily pass data to the process model.Once you create rule inputs in the interface, the rule inputs can be mapped to the process variables in the process model.This makes the process simpler.