Amazon Alexa: Anatomy of a Skill

beSharp
beSharp
Jun 14 · 8 min read

What is Alexa?

Alexa Skills

The anatomy of a skill

A trivial skill

{
"interactionModel": {
"languageModel": {
"invocationName": "saluti",
"intents": [
{
"name": "AMAZON.CancelIntent",
"samples": [
"no",
"niente",
"non fa niente",
"lascia perdere",
"annulla"
]
},
{
"name": "AMAZON.HelpIntent",
"samples": []
},
{
"name": "AMAZON.StopIntent",
"samples": [
"abbandona",
"esci",
"fine",
"stop"
]
},
{
"name": "Salutare",
"slots": [],
"samples": [
"salutarmi",
"salutami",
"saluti",
"ciao"
]
}
],
"types": []
}
}
}
let speechOutput;
let reprompt;
let welcomeOutput = "Benvenuto in 'Ciao' in italiano. Puoi salutarmi per essere salutato a tua volta";
let welcomeReprompt = "puoi solo dire 'ciao' per essere salutato";
"use strict";
const Alexa = require('alexa-sdk');
const APP_ID = undefined;
speechOutput = '';
const handlers = {
'LaunchRequest': function() {
this.emit(':ask', welcomeOutput, welcomeReprompt);
},
'AMAZON.HelpIntent': function() {
speechOutput = 'Placeholder response for AMAZON.HelpIntent.';
reprompt = '';
this.emit(':ask', speechOutput, reprompt);
},
'AMAZON.CancelIntent': function() {
speechOutput = 'Ok, annullato’;
this.emit(':tell', speechOutput);
},
'AMAZON.StopIntent': function() {
speechOutput = 'Arrivederci';
this.emit(':tell', speechOutput);
},
'SessionEndedRequest': function() {
speechOutput = '';
this.emit(':tell', speechOutput);
},
'Salutare': function() {
speechOutput = '';
speechOutput = "Ciao! Questo è tutto quello che puoi fare per ora”;
this.emit(":tell", speechOutput, speechOutput);
},

'Unhandled': function() {
speechOutput = "Non ho capito. Riprova";
this.emit(':ask', speechOutput, speechOutput);
}
};
exports.handler = (event, context) => {
const alexa = Alexa.handler(event, context);
alexa.appId = APP_ID;
// To enable string internationalization (i18n) features, set a resources object.
//alexa.resources = languageStrings;
alexa.registerHandlers(handlers);
//alexa.dynamoDBTableName = 'DYNAMODB_TABLE_NAME'; //uncomment this line to save attributes to DB
alexa.execute();
};
// END of Intent Handlers {} ========================================================================================
// 3. Helper Function =================================================================================================
function resolveCanonical(slot) {
//this function looks at the entity resolution part of request and returns the slot value if a synonyms is provided
let canonical;
try {
canonical = slot.resolutions.resolutionsPerAuthority[0].values[0].value.name;
}
catch (err) {
console.log(err.message);
canonical = slot.value;
};
return canonical;
};
function delegateSlotCollection() {
console.log("in delegateSlotCollection");
console.log("current dialogState: " + this.event.request.dialogState);
if (this.event.request.dialogState === "STARTED") {
console.log("in Beginning");
let updatedIntent = null;
// updatedIntent=this.event.request.intent;
//optionally pre-fill slots: update the intent object with slot values for which
//you have defaults, then return Dialog.Delegate with this updated intent
// in the updatedIntent property
//this.emit(":delegate", updatedIntent); //uncomment this is using ASK SDK 1.0.9 or newer
//this code is necessary if using ASK SDK versions prior to 1.0.9
if (this.isOverridden()) {
return;
}
this.handler.response = buildSpeechletResponse({
sessionAttributes: this.attributes,
directives: getDialogDirectives('Dialog.Delegate', updatedIntent, null),
shouldEndSession: false
});
this.emit(':responseReady', updatedIntent);
}
else if (this.event.request.dialogState !== "COMPLETED") {
console.log("in not completed");
// return a Dialog.Delegate directive with no updatedIntent property.
//this.emit(":delegate"); //uncomment this is using ASK SDK 1.0.9 or newer
//this code necessary is using ASK SDK versions prior to 1.0.9
if (this.isOverridden()) {
return;
}
this.handler.response = buildSpeechletResponse({
sessionAttributes: this.attributes,
directives: getDialogDirectives('Dialog.Delegate', null, null),
shouldEndSession: false
});
this.emit(':responseReady');
}
else {
console.log("in completed");
console.log("returning: " + JSON.stringify(this.event.request.intent));
// Dialog is now complete and all required slots should be filled,
// so call your normal intent handler.
return this.event.request.intent;
}
}
function randomPhrase(array) {
// the argument is an array [] of words or phrases
let i = 0;
i = Math.floor(Math.random() * array.length);
return (array[i]);
}
function isSlotValid(request, slotName) {
let slot = request.intent.slots[slotName];
//console.log("request = "+JSON.stringify(request)); //uncomment if you want to see the request
let slotValue;
//if we have a slot, get the text and store it into speechOutput
if (slot && slot.value) {
//we have a value in the slot
slotValue = slot.value.toLowerCase();
return slotValue;
}
else {
//we didn't get a value in the slot.
return false;
}
}
//These functions are here to allow dialog directives to work with SDK versions prior to 1.0.9
//will be removed once Lambda templates are updated with the latest SDK
function createSpeechObject(optionsParam) {
if (optionsParam && optionsParam.type === 'SSML') {
return {
type: optionsParam.type,
ssml: optionsParam['speech']
};
}
else {
return {
type: optionsParam.type || 'PlainText',
text: optionsParam['speech'] || optionsParam
};
}
}
function buildSpeechletResponse(options) {
let alexaResponse = {
shouldEndSession: options.shouldEndSession
};
if (options.output) {
alexaResponse.outputSpeech = createSpeechObject(options.output);
}
if (options.reprompt) {
alexaResponse.reprompt = {
outputSpeech: createSpeechObject(options.reprompt)
};
}
if (options.directives) {
alexaResponse.directives = options.directives;
}
if (options.cardTitle && options.cardContent) {
alexaResponse.card = {
type: 'Simple',
title: options.cardTitle,
content: options.cardContent
};
if (options.cardImage && (options.cardImage.smallImageUrl || options.cardImage.largeImageUrl)) {
alexaResponse.card.type = 'Standard';
alexaResponse.card['image'] = {};
delete alexaResponse.card.content;
alexaResponse.card.text = options.cardContent;
if (options.cardImage.smallImageUrl) {
alexaResponse.card.image['smallImageUrl'] = options.cardImage.smallImageUrl;
}
if (options.cardImage.largeImageUrl) {
alexaResponse.card.image['largeImageUrl'] = options.cardImage.largeImageUrl;
}
}
}
else if (options.cardType === 'LinkAccount') {
alexaResponse.card = {
type: 'LinkAccount'
};
}
else if (options.cardType === 'AskForPermissionsConsent') {
alexaResponse.card = {
type: 'AskForPermissionsConsent',
permissions: options.permissions
};
}
let returnResult = {
version: '1.0',
response: alexaResponse
};
if (options.sessionAttributes) {
returnResult.sessionAttributes = options.sessionAttributes;
}
return returnResult;
}
function getDialogDirectives(dialogType, updatedIntent, slotName) {
let directive = {
type: dialogType
};
if (dialogType === 'Dialog.ElicitSlot') {
directive.slotToElicit = slotName;
}
else if (dialogType === 'Dialog.ConfirmSlot') {
directive.slotToConfirm = slotName;
}
if (updatedIntent) {
directive.updatedIntent = updatedIntent;
}
return [directive];
}

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