Define process variables / service parameters in visual editor?

I found no way to define process variables in the visual editor, e.g. at the start to initialize a workflow context.
On a related note, I’d like to pass on parameters to a service task, but it seems you can only specify parameters via field injection, but not using parameters like in the API?

In any case, I think the “data flow” is hidden in the visual modeler, e.g. I don’t see any output variables (which can be defined in the “result variable name”), which makes it harder to understand the actual flow.

Note: I’m quite new to the Flowable API and modeler, so I might miss something. All in all I’m really impressed by the slick modeler and even more the lightweight and straightforward Java API!


Process variables can be added at any point during the process instance execution. In expressions you can refer to these variables using the ${varName} pattern. In the Modeler the variables are implicit, so you would have to know as a developer / designer that a certain variable will be present when starting a process instance or added at a later point in the execution. There’s no need to pass variables to service tasks, because a service task will always be able to access the execution instance and its variables.

It would still be nice to add more static variable definitions to the Modeler and provide autocomplete features to expressions etc.

Best regards,


My question is along the same lines - in flowable-modeler how do you define an expression to initialize a form property from a User Task form properties? There is a place for expression but it does not seem to do anything - at least when run in the flowable-task simulation.

Or perhaps the syntax is wrong?