StateMachine

The main "worker" of Structr.Stateflows package is an IStateMachine which provide main functionality related to behavior modelling. It specifies properties and methods allowing to determine whenever we could or couldn't perform certain actions depending on specified entity state. These are:

Property name	Property type	Description
State	TState	Represents current state of entity. TState type could variate but in most cases it's a some kind of enumeration.
PermittedTriggers	IEnumerable	Set of permitted triggers (or actions) in current state of entity. TTrigger is also in most cases an enumeration.

Method name	Description
CanFire	Determines whenever specified trigger can be fired in current state.
Fire	Transition from the current state via the specified trigger. The target state is determined by the configuration of the current state. Actions associated with leaving the current state and entering the new one will be invoked.

The default implementation of IStateMachine provided by Structr.Stateflows uses under the hood the popular lightweight state machine package for .NET - Stateless to perform it's methods. So all configuration process in IStateMachineConfigurator implementations (like IssueStateMachineConfigurator) should be done taking into account Stateless docs.

There are some extensions for Stateless which could be useful while configuring entity behavior:

Method name	Description
InternalTransition	Adds an internal transition without any additional action to the state machine.
InternalTransitionIf	Adds an internal transition with guard condition and without any additional action to the state machine.

When for some reason the Stateless in IStateMachine is not suitable for your needs, it could be replaced by any other implementation on registration step, using special options:

serviceCollection.AddStateflows(x =>
    {
        x.ProviderType = typeof(CustomStateMachineProvider);
    },
    typeof(Program).Assembly);

This would work after you define your own implementation of IStateMachine (some CustomStateMachine for example) which would use some over mechanisms to power CanFire and other methods and properties of IStateMachine. After that just create CustomStateMachineProvider implementing IStateMachineProvider, which will generate instances of your IStateMachine. The code above tells Stateflow to use your CustomStateMachineProvider instead of default.