CanHandleIntentRequest.md

@CanHandleIntentRequest

The @CanHandleIntentRequest method decorator is used on the canHandle method of a RequestHandler class.

Usage

@CanHandleIntentRequest(...intentNames: string[]): (target: any, key: string, descriptor: PropertyDescriptor) => PropertyDescriptor

This decorator accepts the following parameters:

• @CanHandleIntentRequest()
• @CanHandleIntentRequest('intentName')
• @CanHandleIntentRequest('intentName','intentName', ...)

Examples

@CanHandleIntentRequest()

No parameters passed to the decorator. This follows the convention where the intent name will match the name of the handler class or end with Intent.

import { HandlerInput, RequestHandler } from 'ask-sdk';
import { Response } from 'ask-sdk-model';
import { CanHandleIntentRequest } from 'ask-community-decorators';

export class HelloWorldIntentHandler implements RequestHandler {

    @CanHandleIntentRequest()
    canHandle(handlerInput: HandlerInput): boolean {
        
        // original code
        return true;
    }   
}

is equivalent to

import { HandlerInput, RequestHandler } from 'ask-sdk';
import { Response } from 'ask-sdk-model';

export class HelloWorldIntentHandler implements RequestHandler {

    canHandle(handlerInput: HandlerInput): boolean {

        // decorator code
        const possibleIntentNames = ['HelloWorldIntentHandler', 'HelloWorldIntent'];

        const canHandle = handlerInput.requestEnvelope.request.type === 'IntentRequest' 
            && (possibleIntentNames.indexOf(handlerInput.requestEnvelope.request.intent.name) > -1);

        if (canHandle === false) {
            return false;
        }

        // original code
        return true;
    }   
}

@CanHandleIntentRequest('intentName')

A single intent name passed to the decorator.

import { HandlerInput, RequestHandler } from 'ask-sdk';
import { Response } from 'ask-sdk-model';
import { CanHandleIntentRequest } from 'ask-community-decorators';

export class HelloWorldIntentHandler implements RequestHandler {

    @CanHandleIntentRequest('HelloIntent')
    canHandle(handlerInput: HandlerInput): boolean {
        
        // original code
        return true;
    }   
}

is equivalent to

import { HandlerInput, RequestHandler } from 'ask-sdk';
import { Response } from 'ask-sdk-model';

export class HelloWorldIntentHandler implements RequestHandler {

    canHandle(handlerInput: HandlerInput): boolean {

        // decorator code
        const canHandle = handlerInput.requestEnvelope.request.type === 'IntentRequest' 
            && handlerInput.requestEnvelope.request.intent.name === 'HelloIntent';

        if (canHandle === false) {
            return false;
        }

        // original code
        return true;
    }   
}

@CanHandleIntentRequest('intentName', 'intentName')

Multiple intent names passed to the decorator.

import { HandlerInput, RequestHandler } from 'ask-sdk';
import { Response } from 'ask-sdk-model';
import { CanHandleIntentRequest } from 'ask-community-decorators';

export class StopCancelIntentHandler implements RequestHandler {

    @CanHandleIntentRequest('AMAZON.CancelIntent', 'AMAZON.StopIntent')
    canHandle(handlerInput: HandlerInput): boolean {
        
        // original code
        return true;
    }   
}

is equivalent to

import { HandlerInput, RequestHandler } from 'ask-sdk';
import { Response } from 'ask-sdk-model';

export class StopCancelIntentHandler implements RequestHandler {

    canHandle(handlerInput: HandlerInput): boolean {

        // decorator code
        const possibleIntentNames = ['AMAZON.CancelIntent', 'AMAZON.StopIntent'];

        const canHandle = handlerInput.requestEnvelope.request.type === 'IntentRequest' 
            && (possibleIntentNames.indexOf(handlerInput.requestEnvelope.request.intent.name) > -1);

        if (canHandle === false) {
            return false;
        }

        // original code
        return true;
    }   
}