General Guidelines
Variables and Arguments
In general terms of parameters in WF4, there are two main concepts: Variables and Arguments. Variables are used to store data within a task and Arguments are used to pass data in/out of a task. The concept of „binding" parameters has been replaced with the usage of variables and arguments.
Variables are to be used in a task whenever the need to store data is limited to the current task and the output/input of the task is not used anywhere else (for example another task).
Arguments are to be used whenever the input parameters of an activity are given by the user using a web-based application, (for example when executing a task in User Portal) or if the output of an activity is to be returned and used outside of flowster Design Studio application. (for example User Portal).
Each activity has a predefined set of Input/Output parameters. Depending on the requirements and business scenarios, variables and arguments may be required.
Each Input parameter from each activity has an editor. The default editor is the Expression Editor which allows string values to be inserted. In the example below, the activity used is Length (check the Misc->Display Name property) from String Operations library . This activity has one input parameter, with an Expression editors that accept string values. The value "Flowster" was inserted directly in the Expression editor without the use of variables/IN arguments meaning that the value is now embedded in the task after check-in. This represents the basic value insertion for activity parameters.
If the value for the "InputString" parameter should not be embedded in the task and the value would be given on execution time, for example when executing the task from the User Portal, then an IN argument is defined for the "InputString" parameter.
Activity Properties
In general terms of activities properties, there are three main concepts:"Tracking Outputs", „Stop On Error" and „Enabled".
The concept of „Stop on error" and „Enabled"mechanisms are defined for Runtime purposes.
The "Track Outputs" property is defined for Tracking Data panel.
„Stop on error" Property
Th default value for the "Stop On Error" property is set to Yes. When dragging an activity in the Workflow Designer panel, the activity will have this property set to "Yes".
On runtime (nn. Start button), if the "Stop on error" property is set to Yes for an activity, and an error or exception is thrown, the execution of the workflow stops on the activity that caused the error /exception to be thrown.
If "Stop on error" property is set to No, the error message is displayed in Tracking Data panel, but the execution of the workflow continues.
„Enabled" Property
On runtime, if the Enabled property is set to Yes for an activity,the activity is executed.
If set to No, the activity will be disabled and it will not be executed on runtime.
"Track Outputs" property
If set to Yes, the result of the executed activities will be displayed in the Tracking Data panel.
The result displayed in Tracking Data panel represents the output of the activity "CollectionFromString".
If set to No, the result of the executed activities will not be displayed in the Tracking Data panel.
