uē-tôo

Appearance

@ue-too/being / StateDefinition

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

Defined in: schema-factory.ts:163

Definition of a single state in the state machine.

Example ​

typescript
{
  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