Question

I have a model and a column of this model represents a state . It’s numeric value and it could be 1,2,3.

I have two concerns:

a) Based on the business logic, the state can only go from 1 to 2 and from 2 to 3. It can’t go back from higher numbers to lower number and it can’t just from 1 to 3 in one step.

b) I don’t want to expose these numbers to controllers (don’t like magical numbers flying around).

I did following

• I created methods like stateX?, stateY?, stateZ? to allow controllers check current state.
  This helps me with concern b).

• I created methods setStateX, setStateY, stateZ and raise in them, if a controller does unacceptable switch of state. This helps me with concern a) and b).

However, I feel that’s more Java/C++ way (which is my background) – 6 methods to do one thing.

Is there any better way to accomplish this in RoR?

Answer 1

Not sure if this is still the best way to do it (my Rails is a little rusty) but there is a gem called acts_as_state_machine which I think will do exactly what you want.