javascript - 如何管理对异步服务的可变调用次数

Question

给定:

[1,2,3,4,5] variable array of numbers

我想为数组中的每个数字调用一个异步方法。有哪些方法可以解决这个问题？异步方法的返回类型为 JSON。

我期待的是一个包含调用结果的新 JSON 数组

[{id:1,name:"name1"},
{id:2,name:"name2"},
{id:3,name:"name3"},
{id:4,name:"name4"},
{id:5,name:"name5"}]

最新结果

app.js

( () => {
    const result =  adapterContext.get([1, 2, 3]);
    console.log(result);
})();

service.js

exports.get = list => {
    Promise.all(list.map(promise-method-call))
        .then(function (response) {
            console.log("response", response);
            return response;
        }).catch(function (error) {
            console.log("oops ", error);
        });
};

结果

Why is the console.log(result) undefined?

undefined  
response [ '{"hello":1}', '{"hello":2}', '{"hello":3}' ]  

Answer 1

你快到了。首先，您需要从您的服务返回 Promise.all 调用:

exports.get = list => {
  // Make sure to return the promise!
  return Promise.all(list.map(promise-method-call))
    .then(function (response) {
      console.log("response", response);
      return response;
    }).catch(function (error) {
      console.log("oops ", error);
    });
};

---

然后，在您的应用程序内部需要等待 get 方法完成。有两种方法可以做到这一点:

老派 .then 链接:

(() => {
  const result =  adapterContext.get([1, 2, 3]).then(result => {
    console.log(result);
  });
})();

酷 child 异步/等待

(async () => {
  const result = await adapterContext.get([1, 2, 3]);
  console.log(result);
})();