class Expression 🔹

Language	Type name
.NET	Amazon.CDK.AWS.IoTEvents.Expression
Java	software.amazon.awscdk.services.iotevents.Expression
Python	aws_cdk.aws_iotevents.Expression
TypeScript (source)	@aws-cdk/aws-iotevents » Expression

Expression for events in Detector Model state.

See also: https://docs.aws.amazon.com/iotevents/latest/developerguide/iotevents-expressions.html

Example

import * as iotevents from '@aws-cdk/aws-iotevents';
import * as actions from '@aws-cdk/aws-iotevents-actions';

declare const input: iotevents.IInput;

const state = new iotevents.State({
  stateName: 'MyState',
  onEnter: [{
    eventName: 'test-event',
    condition: iotevents.Expression.currentInput(input),
    actions: [
      actions: [
        new actions.SetVariableAction(
          'MyVariable',
          iotevents.Expression.inputAttribute(input, 'payload.temperature'),
        ),
      ],
    ],
  }],
});

Initializer

new Expression()

Methods

Name	Description
evaluate(parentPriority?)🔹	This is called to evaluate the expression.
static and(left, right)🔹	Create a expression for the AND operator.
static currentInput(input)🔹	Create a expression for function currentInput().
static eq(left, right)🔹	Create a expression for the Equal operator.
static fromString(value)🔹	Create a expression from the given string.
static gt(left, right)🔹	Create a expression for the Greater Than operator.
static gte(left, right)🔹	Create a expression for the Greater Than Or Equal operator.
static inputAttribute(input, path)🔹	Create a expression for get an input attribute as $input.TemperatureInput.temperatures[2].
static lt(left, right)🔹	Create a expression for the Less Than operator.
static lte(left, right)🔹	Create a expression for the Less Than Or Equal operator.
static neq(left, right)🔹	Create a expression for the Not Equal operator.
static or(left, right)🔹	Create a expression for the OR operator.

---

evaluate(parentPriority?)🔹

public evaluate(parentPriority?: number): string

Parameters

• parentPriority number — priority of the parent of this expression, used for determining whether or not to add parenthesis around the expression.

Returns

• string

This is called to evaluate the expression.

---

static and(left, right)🔹

public static and(left: Expression, right: Expression): Expression

Parameters

• left Expression
• right Expression

Returns

• Expression

Create a expression for the AND operator.

---

static currentInput(input)🔹

public static currentInput(input: IInput): Expression

Parameters

• input IInput

Returns

• Expression

Create a expression for function currentInput().

It is evaluated to true if the specified input message was received.

---

static eq(left, right)🔹

public static eq(left: Expression, right: Expression): Expression

Parameters

• left Expression
• right Expression

Returns

• Expression

Create a expression for the Equal operator.

---

static fromString(value)🔹

public static fromString(value: string): Expression

Parameters

• value string

Returns

• Expression

Create a expression from the given string.

---

static gt(left, right)🔹

public static gt(left: Expression, right: Expression): Expression

Parameters

• left Expression
• right Expression

Returns

• Expression

Create a expression for the Greater Than operator.

---

static gte(left, right)🔹

public static gte(left: Expression, right: Expression): Expression

Parameters

• left Expression
• right Expression

Returns

• Expression

Create a expression for the Greater Than Or Equal operator.

---

static inputAttribute(input, path)🔹

public static inputAttribute(input: IInput, path: string): Expression

Parameters

• input IInput
• path string

Returns

• Expression

Create a expression for get an input attribute as $input.TemperatureInput.temperatures[2].

---

static lt(left, right)🔹

public static lt(left: Expression, right: Expression): Expression

Parameters

• left Expression
• right Expression

Returns

• Expression

Create a expression for the Less Than operator.

---

static lte(left, right)🔹

public static lte(left: Expression, right: Expression): Expression

Parameters

• left Expression
• right Expression

Returns

• Expression

Create a expression for the Less Than Or Equal operator.

---

static neq(left, right)🔹

public static neq(left: Expression, right: Expression): Expression

Parameters

• left Expression
• right Expression

Returns

• Expression

Create a expression for the Not Equal operator.

---

static or(left, right)🔹

public static or(left: Expression, right: Expression): Expression

Parameters

• left Expression
• right Expression

Returns

• Expression

Create a expression for the OR operator.