Adding Variables to the Pipeline
In the Pipeline view, you can add variables that were not declared as input or output parameters for the flow service itself or any of its constituent services. You can add variables that were omitted from a service’s input or output parameters or create temporary variables for use within the flow. For example, you might attach a variable to each of the children in a BRANCH step to mark the path taken by the service at run time.
Variables that you add to the pipeline can be used just like any declared variable in the flow.
Keep the following points in mind when adding variable to the pipeline:
If you create a new variable in a flow, you must
immediately do one of the following:
Link a variable to it
Assign a value to it
Drop it
If you do not take one of these steps, Designer automatically clears it from the pipeline.
You might want to drop a variable immediately after adding it if a service produces a variable that is not declared in the service input or output parameters. The variable will not appear in the Pipeline view if it is not an input or output parameter. By adding and then immediately dropping the variable, you can delete the variable if it does exist in the pipeline.
To add a variable to the pipeline
1. In the flow service editor, select the INVOKE or MAP step that represents the stage of the pipeline at which you want to add a new variable.
2. Do one of the following in the Pipeline view:
Select the point in the pipeline where you want to add the new variable (
Pipeline In,
Service In,
Service Out, or
Pipeline Out). Click
and select the type of variable that you want to create.
In the Palette view that is part of Pipeline view, under Variables, select the variable that you want to add and then select the point in the pipeline where you want to add it. The Palette view is located within the Pipeline view. Click
to show the Palette view. Click
to hide the Palette view.
3. Type a name for the variable and press ENTER.
4. With the variable selected, set variable properties and apply constraints using the Properties view.
5. If the variable is a Document or a Document List, add more variables to define its contents. Then use 
to indent each member variable beneath the Document or Document List variable. 6. Do one of the following with the new variable:
Link the variable to another variable.
Assign a value to the variable using
on the Pipeline view toolbar.
Drop the variable.