Question

建立需要持久性的Alexa技能。

我正在调用数据库以在管理流程之前获取用户详细信息，而我正努力让Node等待DynamoDB的响应（使用Dynasty.js处理数据库连接）。

我尝试了很多不同的Promise / Callback / Node“阻止” /异步方法，而我能做的最好的就是在用户退出技能时出现响应（在CloudWatch日志中）。我真的希望用户配置在过程的开始而不是结束时进行！

var credentials = {
    accessKeyId: process.env.MY_ACCESS_KEY_ID,
    secretAccessKey: process.env.MY_SECRET_ACCESS_KEY
};

var dynasty = require('dynasty')(credentials);
var tableName = dynasty.table('dynamoTable');

const promiseFunc = new Promise((resolve,reject)=>{
  var myUser = tableName.find(userId);
  setTimeout(_=>{resolve(myUser)}, 2000);
});

var checkUser = async function(){
	if (true) {
		console.log('check, check, 1, 2, 3');
		await promiseFunc.then(function(myUser) {
			if (myUser) {
				console.log("USER FOUND");
				console.log(myUser);
			} else {
				console.log("no user! sigh deeply and start again");
			}
		})
	}
	console.log("do more stuff now");
}

exports.handler = function(event, context) {	
	
  userId = event.session.user.userId;
	const alexa = Alexa.handler(event, context);
	
  // only check the first time, and only once the userId is properly constructed
	if (!(userId.startsWith('amzn1.ask.account.testUser')) && (checkedUser != 1)) {
		checkedUser = 1;
		checkUser();
	}
	
	alexa.resources = languageString;
	alexa.registerHandlers(newSessionHandlers, startStateHandlers, triviaStateHandlers, helpStateHandlers, stopStateHandlers);
	alexa.execute();
};

在其余脚本运行之前，如何让节点等待dynamoDB的响应...

Answer 1

这是一个古老的链接，但是according to it可以通过.promise()方法从DynamoDB获得承诺。考虑到这一点...

function findUser(userId) {
    // initialize tableName somehow
    return tableName.find(userId)
}

async function checkUser() {
    // initialize userId somehow
   let myUser = await findUser(userId);
   console.log(`found user ${myUser}`);
   return myUser;
}

最后，请记住等待对checkUser（）的调用...

if (/* long condition */) {
    checkedUser = 1;
    let myUser = await checkUser();
}

在Alexa输出之前从DynamoDB返回Promise

1 个答案: