amir734jj/SimpleFSM

Simple FSM implementation using Enums and Functions

SimpleFSM

This FSM uses Enum to keep track of states and Functions to handler the transitions from one state to another.

Nuget

This Enum keeps track of the state:

public enum TestStates
{
    Start,
    Step1,
    Step2,
    Step3,
    End
}

Payload class:

public class TestPayload
{
    public string Value { get; set; }
}

Building the FSM using the builder:

var paylod = new TestPayload();

var fsm = SimpleFsmBuilder<TestStates, TestPayload>.New()
    // Set start state
    .SetStartState(TestStates.Start)
    // Set end state
    .SetEndState(TestStates.End)
    // Add un-conditional transition from Start to Step1
    .AddTransition(TestStates.Start, TestStates.Step1)

    // Add Handler from step1 -> Step2
    .AddHandler(TestStates.Step1, (currentState, payload) =>
    {
        payload.Value = "Test1";
        // Destination state
        return TestStates.Step2;
    })
    // Add Handler from Step2 -> Step3
    .AddHandler(TestStates.Step2, (currentState, payload) =>
    {
        payload.Value = "Test2";
        // Destination state
        return TestStates.Step3;
    })
    // Add Handler from Step3 -> End
    .AddHandler(TestStates.Step3, (currentState, payload) =>
    {
        payload.Value = "Test3";
        // Destination state
        return TestStates.End;
    })
    // Add Exception handler
    .SetExceptionHandler((currentState, payload, exception) =>
    {
        // Validate the exception
        Assert.Equal(expectedException, exception);
        // Stop
        return TestStates.End;
    })    
    .Build();

// Run the machine given the payload
fsm.Start(paylod);
// or fsm.StartAsync(paylod)