How To Accumulate Data Across Multiple Events And States?

[rs-georg]

Imagine a form or wizard that has multiple steps. Each steps collects data, then moves to the next step. In the final step, all data collected in the previous steps should be available so it can be processed/uploaded/...

Is this possible? How could it be done?

For example

• Step 1
  Get username and email
  machine.processEvent(UserData(username, email))
  --> transition to Step 2
• Step 2
  Get city and street
  machine.processEvent(Location(city, street))
  --> transition to Step 3
• Step 3
  Ask for favorite food
  machine.processEvent(FavoriteFood("pizza"))
  --> transition to Step 4
• Step 4
  Search for restaurant that serves pizza in the provided city close to the street
  --> This means we need to have all the data from previous states in this last state

[nsk90]

Hi, sorry looks I missed your question.

There is no some built-in helper for such task, so the most strait-forward way seems to be using State subclasses for each step.
In State subclasses (steps) your can declare properties to hold all the necessary data. And fill it when the step is complete.
At the last step you can get all that properties from states (by direct references or using findState api).
Alternatively you can store all per-step data in some separate data structure (outside of StateMachine).