> **Experimental**
>
> `@aws-cdk/aws-iotevents-alpha` is an [**experimental**](/stability) (alpha) package: its API may change in any release, without a major version bump.
# TransitionOptions

Properties for options of state transition.

- Stability: [Experimental](/cdk/api/stability.html)
- Source: [`lib/state.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0-alpha.0/packages/@aws-cdk/aws-iotevents-alpha/lib/state.ts#L10)

## Example

```ts
import * as iotevents from '@aws-cdk/aws-iotevents-alpha';
import * as actions from '@aws-cdk/aws-iotevents-actions-alpha';
import * as lambda from 'aws-cdk-lib/aws-lambda';

declare const func: lambda.IFunction;

const input = new iotevents.Input(this, 'MyInput', {
  inputName: 'my_input', // optional
  attributeJsonPaths: ['payload.deviceId', 'payload.temperature'],
});

const warmState = new iotevents.State({
  stateName: 'warm',
  onEnter: [{
    eventName: 'test-enter-event',
    condition: iotevents.Expression.currentInput(input),
    actions: [new actions.LambdaInvokeAction(func)], // optional
  }],
  onInput: [{ // optional
    eventName: 'test-input-event',
    actions: [new actions.LambdaInvokeAction(func)],
  }],
  onExit: [{ // optional
    eventName: 'test-exit-event',
    actions: [new actions.LambdaInvokeAction(func)],
  }],
});
const coldState = new iotevents.State({
  stateName: 'cold',
});

// transit to coldState when temperature is less than 15
warmState.transitionTo(coldState, {
  eventName: 'to_coldState', // optional property, default by combining the names of the States
  when: iotevents.Expression.lt(
    iotevents.Expression.inputAttribute(input, 'payload.temperature'),
    iotevents.Expression.fromString('15'),
  ),
  executing: [new actions.LambdaInvokeAction(func)], // optional
});
// transit to warmState when temperature is greater than or equal to 15
coldState.transitionTo(warmState, {
  when: iotevents.Expression.gte(
    iotevents.Expression.inputAttribute(input, 'payload.temperature'),
    iotevents.Expression.fromString('15'),
  ),
});

new iotevents.DetectorModel(this, 'MyDetectorModel', {
  detectorModelName: 'test-detector-model', // optional
  description: 'test-detector-model-description', // optional property, default is none
  evaluationMethod: iotevents.EventEvaluation.SERIAL, // optional property, default is iotevents.EventEvaluation.BATCH
  detectorKey: 'payload.deviceId', // optional property, default is none and single detector instance will be created and all inputs will be routed to it
  initialState: warmState,
});
```

## Properties

- `eventName`: string — The name of the event.

  **Default:** string combining the names of the States as `${originStateName}_to_${targetStateName}`

- `executing`: [IAction](/cdk/api/v2/docs/@aws-cdk_aws-iotevents-alpha.IAction.html)[] — The actions to be performed with the transition.

  **Default:** no actions will be performed

- `when`: [Expression](/cdk/api/v2/docs/@aws-cdk_aws-iotevents-alpha.Expression.html) (required) — The condition that is used to determine to cause the state transition and the actions.

  When this was evaluated to `true`, the state transition and the actions are triggered.