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Alexa NodeJS Skill

Resources

  1. Sample NodeJS Howto
  2. CDK Event Sources
  3. Lambdba Event Targets

tl;dr

  1. Create Lambda Function
  2. Add Alexa Skillskit trigger
  3. Add the code (examples) below
  4. Grab the ARN from the top-right and add it the Alexa developer portal

Notes

You may need to add the trigger yourself to the Lambda function.

Example code

index.js:

/* eslint-disable  func-names */
/* eslint-disable  no-console */

const Alexa = require('ask-sdk-core');
const recipes = require('./recipes');
const i18n = require('i18next');
const sprintf = require('i18next-sprintf-postprocessor');

/* INTENT HANDLERS */
const LaunchRequestHandler = {
  canHandle(handlerInput) {
    return handlerInput.requestEnvelope.request.type === 'LaunchRequest';
  },
  handle(handlerInput) {
    const requestAttributes = handlerInput.attributesManager.getRequestAttributes();
    const sessionAttributes = handlerInput.attributesManager.getSessionAttributes();

    const item = requestAttributes.t(
      getRandomItem(Object.keys(recipes.RECIPE_EN_US)),
    );

    const speakOutput = requestAttributes.t(
      'WELCOME_MESSAGE',
      requestAttributes.t('SKILL_NAME'),
      item,
    );
    const repromptOutput = requestAttributes.t('WELCOME_REPROMPT');

    handlerInput.attributesManager.setSessionAttributes(sessionAttributes);

    return handlerInput.responseBuilder
      .speak(speakOutput)
      .reprompt(repromptOutput)
      .getResponse();
  },
};

const RecipeHandler = {
  canHandle(handlerInput) {
    return (
      handlerInput.requestEnvelope.request.type === 'IntentRequest' &&
      handlerInput.requestEnvelope.request.intent.name === 'RecipeIntent'
    );
  },
  handle(handlerInput) {
    const requestAttributes = handlerInput.attributesManager.getRequestAttributes();
    const sessionAttributes = handlerInput.attributesManager.getSessionAttributes();

    const itemSlot = handlerInput.requestEnvelope.request.intent.slots.Item;
    let itemName;
    if (itemSlot && itemSlot.value) {
      itemName = itemSlot.value.toLowerCase();
    }

    const cardTitle = requestAttributes.t(
      'DISPLAY_CARD_TITLE',
      requestAttributes.t('SKILL_NAME'),
      itemName,
    );
    const myRecipes = requestAttributes.t('RECIPES');
    const recipe = myRecipes[itemName];
    let speakOutput = '';

    if (recipe) {
      sessionAttributes.speakOutput = recipe;
      // uncomment the _2_ reprompt lines if you want to repeat the info
      // and prompt for a subsequent action
      // sessionAttributes.repromptSpeech = requestAttributes.t('RECIPE_REPEAT_MESSAGE');
      handlerInput.attributesManager.setSessionAttributes(sessionAttributes);

      return (
        handlerInput.responseBuilder
          .speak(sessionAttributes.speakOutput)
          // .reprompt(sessionAttributes.repromptSpeech)
          .withSimpleCard(cardTitle, recipe)
          .getResponse()
      );
    }
    const repromptSpeech = requestAttributes.t('RECIPE_NOT_FOUND_REPROMPT');
    if (itemName) {
      speakOutput += requestAttributes.t(
        'RECIPE_NOT_FOUND_WITH_ITEM_NAME',
        itemName,
      );
    } else {
      speakOutput += requestAttributes.t('RECIPE_NOT_FOUND_WITHOUT_ITEM_NAME');
    }
    speakOutput += repromptSpeech;

    // save outputs to attributes, so we can use it to repeat
    sessionAttributes.speakOutput = speakOutput;
    sessionAttributes.repromptSpeech = repromptSpeech;

    handlerInput.attributesManager.setSessionAttributes(sessionAttributes);

    return handlerInput.responseBuilder
      .speak(sessionAttributes.speakOutput)
      .reprompt(sessionAttributes.repromptSpeech)
      .getResponse();
  },
};

const HelpHandler = {
  canHandle(handlerInput) {
    return (
      handlerInput.requestEnvelope.request.type === 'IntentRequest' &&
      handlerInput.requestEnvelope.request.intent.name === 'AMAZON.HelpIntent'
    );
  },
  handle(handlerInput) {
    const requestAttributes = handlerInput.attributesManager.getRequestAttributes();
    const sessionAttributes = handlerInput.attributesManager.getSessionAttributes();

    const item = requestAttributes.t(
      getRandomItem(Object.keys(recipes.RECIPE_EN_US)),
    );

    sessionAttributes.speakOutput = requestAttributes.t('HELP_MESSAGE', item);
    sessionAttributes.repromptSpeech = requestAttributes.t(
      'HELP_REPROMPT',
      item,
    );

    return handlerInput.responseBuilder
      .speak(sessionAttributes.speakOutput)
      .reprompt(sessionAttributes.repromptSpeech)
      .getResponse();
  },
};

const RepeatHandler = {
  canHandle(handlerInput) {
    return (
      handlerInput.requestEnvelope.request.type === 'IntentRequest' &&
      handlerInput.requestEnvelope.request.intent.name === 'AMAZON.RepeatIntent'
    );
  },
  handle(handlerInput) {
    const sessionAttributes = handlerInput.attributesManager.getSessionAttributes();

    return handlerInput.responseBuilder
      .speak(sessionAttributes.speakOutput)
      .reprompt(sessionAttributes.repromptSpeech)
      .getResponse();
  },
};

const ExitHandler = {
  canHandle(handlerInput) {
    return (
      handlerInput.requestEnvelope.request.type === 'IntentRequest' &&
      (handlerInput.requestEnvelope.request.intent.name ===
        'AMAZON.StopIntent' ||
        handlerInput.requestEnvelope.request.intent.name ===
          'AMAZON.CancelIntent')
    );
  },
  handle(handlerInput) {
    const requestAttributes = handlerInput.attributesManager.getRequestAttributes();
    const speakOutput = requestAttributes.t(
      'STOP_MESSAGE',
      requestAttributes.t('SKILL_NAME'),
    );

    return handlerInput.responseBuilder.speak(speakOutput).getResponse();
  },
};

const SessionEndedRequestHandler = {
  canHandle(handlerInput) {
    console.log('Inside SessionEndedRequestHandler');
    return handlerInput.requestEnvelope.request.type === 'SessionEndedRequest';
  },
  handle(handlerInput) {
    console.log(
      `Session ended with reason: ${JSON.stringify(
        handlerInput.requestEnvelope,
      )}`,
    );
    return handlerInput.responseBuilder.getResponse();
  },
};

const ErrorHandler = {
  canHandle() {
    return true;
  },
  handle(handlerInput, error) {
    console.log(`Error handled: ${error.message}`);

    return handlerInput.responseBuilder
      .speak("Sorry, I can't understand the command. Please say again.")
      .reprompt("Sorry, I can't understand the command. Please say again.")
      .getResponse();
  },
};

/* Helper Functions */

// Finding the locale of the user
const LocalizationInterceptor = {
  process(handlerInput) {
    const localizationClient = i18n.use(sprintf).init({
      lng: handlerInput.requestEnvelope.request.locale,
      overloadTranslationOptionHandler:
        sprintf.overloadTranslationOptionHandler,
      resources: languageStrings,
      returnObjects: true,
    });

    const attributes = handlerInput.attributesManager.getRequestAttributes();
    attributes.t = function(...args) {
      return localizationClient.t(...args);
    };
  },
};

// getRandomItem
function getRandomItem(arrayOfItems) {
  // the argument is an array [] of words or phrases
  let i = 0;
  i = Math.floor(Math.random() * arrayOfItems.length);
  return arrayOfItems[i];
}

/* LAMBDA SETUP */
const skillBuilder = Alexa.SkillBuilders.custom();
exports.handler = skillBuilder
  .addRequestHandlers(
    LaunchRequestHandler,
    RecipeHandler,
    HelpHandler,
    RepeatHandler,
    ExitHandler,
    SessionEndedRequestHandler,
  )
  .addRequestInterceptors(LocalizationInterceptor)
  .addErrorHandlers(ErrorHandler)
  .lambda();

// langauge strings for localization
// TODO: The items below this comment need your attention

const languageStrings = {
  en: {
    translation: {
      RECIPES: recipes.RECIPE_EN_US,
      SKILL_NAME: 'Minecraft Helper',
      WELCOME_MESSAGE:
        "Welcome to %s. You can ask a question like, what's the recipe for a %s? ... Now, what can I help you with?",
      WELCOME_REPROMPT:
        'For instructions on what you can say, please say help me.',
      DISPLAY_CARD_TITLE: '%s  - Recipe for %s.',
      HELP_MESSAGE:
        "You can ask questions such as, what's the recipe for a %s, or, you can say exit...Now, what can I help you with?",
      HELP_REPROMPT:
        "You can say things like, what's the recipe for a %s, or you can say exit...Now, what can I help you with?",
      STOP_MESSAGE: 'Goodbye!',
      RECIPE_REPEAT_MESSAGE: 'Try saying repeat.',
      RECIPE_NOT_FOUND_WITH_ITEM_NAME:
        "I'm sorry, I currently do not know the recipe for %s. ",
      RECIPE_NOT_FOUND_WITHOUT_ITEM_NAME:
        "I'm sorry, I currently do not know that recipe. ",
      RECIPE_NOT_FOUND_REPROMPT: 'What else can I help with?',
    },
  },
  'en-US': {
    translation: {
      RECIPES: recipes.RECIPE_EN_US,
      SKILL_NAME: 'American Minecraft Helper',
    },
  },
  'en-GB': {
    translation: {
      RECIPES: recipes.RECIPE_EN_GB,
      SKILL_NAME: 'British Minecraft Helper',
    },
  },
  de: {
    translation: {
      RECIPES: recipes.RECIPE_DE_DE,
      SKILL_NAME: 'Assistent für Minecraft in Deutsch',
      WELCOME_MESSAGE:
        'Willkommen bei %s. Du kannst beispielsweise die Frage stellen: Welche Rezepte gibt es für eine %s? ... Nun, womit kann ich dir helfen?',
      WELCOME_REPROMPT:
        'Wenn du wissen möchtest, was du sagen kannst, sag einfach „Hilf mir“.',
      DISPLAY_CARD_TITLE: '%s - Rezept für %s.',
      HELP_MESSAGE:
        'Du kannst beispielsweise Fragen stellen wie „Wie geht das Rezept für eine %s“ oder du kannst „Beenden“ sagen ... Wie kann ich dir helfen?',
      HELP_REPROMPT:
        'Du kannst beispielsweise Sachen sagen wie „Wie geht das Rezept für eine %s“ oder du kannst „Beenden“ sagen ... Wie kann ich dir helfen?',
      STOP_MESSAGE: 'Auf Wiedersehen!',
      RECIPE_REPEAT_MESSAGE: 'Sage einfach „Wiederholen“.',
      RECIPE_NOT_FOUND_WITH_ITEM_NAME:
        'Tut mir leid, ich kenne derzeit das Rezept für %s nicht. ',
      RECIPE_NOT_FOUND_WITHOUT_ITEM_NAME:
        'Tut mir leid, ich kenne derzeit dieses Rezept nicht. ',
      RECIPE_NOT_FOUND_REPROMPT: 'Womit kann ich dir sonst helfen?',
    },
  },
};

recipes.js

/* eslint-disable  func-names */
/* eslint-disable max-len */
/* eslint quote-props: ['error', 'consistent'] */
// TODO: Replace this data with your own.
module.exports = {
  RECIPE_EN_GB: {
    'snow golem':
      'A snow golem can be created by placing a pumpkin on top of  two snow blocks on the ground.',
    'pillar quartz block':
      'A pillar of quartz can be obtained by placing a block of quartz on top of a block of quartz in mine craft.',
    // ...omittd
  },
};

Example package.json

{
  "name": "how-to",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "ask-sdk-core": "^2.0.0",
    "ask-sdk-model": "^1.0.0",
    "i18next": "^10.5.0",
    "i18next-sprintf-postprocessor": "^0.2.2"
  }
}

Repository

https://github.com/okeeffed/developer-notes-nextjs/content/alexa/nodejs-skill

Sections

Resources
tl;dr
Notes
Example code
Example package.json

Related

Alexa
nodejs-skill