将 promise 的值返回给另一个函数 [英] Returning the value of a promise to another function

问题描述

我正在尝试在 renderSelect 中获取 PromiseValue.(在 tmp 中)

I'm trying to get the PromiseValue in the renderSelect. (in tmp)

问题是我得到了一个承诺，这是正常的行为.但我不明白如何获取 Promise 中的值以便我可以使用它们.

The thing is that I'm getting a promise, which is the normal behavior. But I don't understand how could I get the values inside the Promise so I can work with them.

我有一个 ApiService 类，如下

handleResponse(response) {
  if (response.status >= 200 && response.status < 300) {
    return response.json();
  }
  return response.json()
    .then((res) => {
      throw new Error(res.message);
    },
    () => {
      throw new Error();
    });
}


get(url) {
  return fetch(`${this.API_URL}${url}`, {
    method: 'GET',
    headers: this.headers,
  })
    .then(response => this.handleResponse(response));
}

还有我的 .jsx 像这样

const getOptions = (contractor_employee_id) => {
  const apiService = new ApiService()
  return apiService
    .get(`some_url`)
    .then(
      response => {
        return ["toto", "tata", "titi"]
    },
    err => (console.log("Failed"))
    );
};

const renderSelect = (field) => {
  const tmp = getOptions(field.id)
  console.log(tmp)

推荐答案

Promises 是异步的.如果您想以同步方式返回承诺结果，请使用 async/await.

Promises are asynchronous. And if you want to return promise result in synchronous way, use async / await.

const renderSelect = async (field) => {
    const tmp = await getOptions(field.id)
    console.log(tmp)
}

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