@ue-too/being / index / StateDefinition

Interface: StateDefinition<Context, EventPayloadMapping, StateNames, EventOutputMapping>

Defined in: schema-factory.ts:163

Definition of a single state in the state machine.

Example

{
  name: "PAYING",
  guards: {
    hasEnoughBalance: (context) => context.balance >= context.itemPrice,
    hasInsufficientBalance: (context) => context.balance < context.itemPrice,
  },
  transitions: [
    {
      event: "pay",
      targetState: "SELECTING",
      guards: [
        { guard: "hasEnoughBalance", targetState: "CONFIRMED" },
        { guard: "hasInsufficientBalance", targetState: "PAYING" },
      ],
    },
  ],
}

Type Parameters

Context

Context extends BaseContext = BaseContext

The context type

EventPayloadMapping

EventPayloadMapping = any

Mapping of event names to their payload types

StateNames

StateNames extends string = string

Union type of all valid state names

EventOutputMapping

EventOutputMapping extends Partial<Record<keyof EventPayloadMapping, unknown>> = DefaultOutputMapping<EventPayloadMapping>

Optional mapping of events to their output types

Properties

guards?

optional guards: Record<string, GuardFunction<Context>>

Defined in: schema-factory.ts:188

Optional mapping of guard names to guard functions. Guards defined here can be reused across multiple transitions within this state by referencing them by name in the transition's guards array.

The guard functions receive the context parameter typed with the Context type parameter, not BaseContext, so you get full type safety for your context properties.

---

name

name: StateNames

Defined in: schema-factory.ts:172

Name of this state

---

onEnter()?

optional onEnter: (context, fromState) => void

Defined in: schema-factory.ts:190

Optional callback when entering this state

Parameters

context

Context

fromState

StateNames

Returns

void

---

onExit()?

optional onExit: (context, toState) => void

Defined in: schema-factory.ts:192

Optional callback when exiting this state

Parameters

context

Context

toState

StateNames

Returns

void

---

transitions

transitions: TransitionDefinitionUnion<Context, EventPayloadMapping, StateNames, EventOutputMapping>[]

Defined in: schema-factory.ts:174

Transitions available from this state