Parametrization is the process in which you replace hard coded values in Action logic with symbolic variables. It promotes modularity, reusability and ensures long term maintainability of test assets.
Input Parameters for Action indicate the values that a Scenario will supply during the time test is executed. It allows the same Action to be exercised with different values for these inputs. It enables data driven testing for a Scenario.
Data Source for Input Parameter
Indicates the list of permissible values for the given Action input, as a guide.
If the data for the parameter can be represented in a classification driven by business semantics. Read more about Data Type
If the parameter can only accept a restricted set of values. Read more about Data List
There is no specific guidance on what kind of values can be provided to this Action Input.
Both Data Type and Data List options allow automated date generation at Scenario level for covering various permutations using data driven testing.
An Action can define a set of Output Parameters so that it can return information that may be useful for subsequent Actions in a Scenario.
"Select Flight" Action in "Flight Listing Page" Context could indicate Price as an Output Parameter.
Action logic has to ensure that the price is set, as scanned from the flight listing page. This parameter value can be used as input to other Actions in the Scenario.
"Review Trip Details" Action in the "Payment Information Page" could receive this as an input parameter as Expected Price.