I'm currently making a task-specific screen that's like a custom task box, but only for a specific group of tasks. One of the things I need to do is to gather additional data from a number of tables, not just display the information from the action. The problem is that there is no direct link between an action and the associated entity (the entity whose Create triggers the process).
It's possible to set "Expose Process Entity" to Yes, and have a pseudo-entity "Process_XXXX" (where XXXX is the name of the process), which has this link. The problem there is that a) the pseudi-entity cannot be set public and b) the screen displaying the "task box" is in the UI layer, while the BPT process has its own eSpace in the orchestration layer, and it's a big no-no to have circular reference by eSpaces referencing other eSpaces in a layer higher up.
I need the Action Id since I need to call an ActivityOpen when the user decides to start the activity. I currently solved this by joining process_input (which holds the Id-value) via Process to Activity. But I feel this should be a system Action.