Expression: JSON handling of process variable

Consider a process variable “foo” of type String. The value of this variable contains a valid JSON in string representation. I would like to access a property in the JSON object in an expression in the process definition of a (service) task.

Process variable:

  • Key: foo
  • Type: string
  • Value: {“a”: [0, 1, 2]}

I would to access the value from the property “a”. Can I make an expression in a process definition for this?

In Camunda this seems possible:

Is this possible in Flowable as well?