React - 异步api调用，Promise.all等待调用完成

Question

An api call I have returns this (general list of schedules):

const schedules = {
  data: [
    {
      id: "2147483610",
      selfUri: "/schedules/2147483610",
      type: "Schedule",
      status: "Pending"
    },
    {
      id: "2147650434",
      selfUri: "/schedules/2147650434",
      type: "Schedule",
      status: "Pending"
    }
  ],

These schedules won't initiate on the server until each schedule.data.selfUri is individually requested. So is there a way to pull each of the selfUri's and request each of them in a different api call?

Using Promise.all is this the correct approach?

Promise.all(this.state.scheduleUri.map((uri) => { return axios.get(uri, ...); }));

Normally with axios I'd do something like this:

axios({
  method: "get",
  url: `/get/data`
})
.then(response => {
    console.log(response);
    this.setState(
      {
        someState: response.data
      });
  })
  .catch(error => console.log(error.response));
};

Answer 1

Yes, a combination between a single Promise and a Promise.all will do the trick.

Here's how I would approach this:

// Step 1: get your schedules list.
axios.get('/get/schedules')
  .then(response => {
    const schedules = response.data;

    // Step 2: get each of your schedules selfUri data.
    // This line gets called after the schedule list is received
    // However, Promise.all executes all calls asynchroniously, at once.
    return Promise.all(schedules.map(schedule => axios.get(schedule.selfUri)));
  }
  .then(responseArray => {
    // Step 3: Finally, here you have available
    // the responses from the Promise.all call in Step 2.
    // Or in other words, responseArray holds the response
    // for each of the selfUri calls.

    this.setState({
      // do whatever you want with the data ;-)
    })
  })
  .catch(error => console.log(error.response));

Sounds like a plan to me.

Answer 2

You don't need to wait for all requests to finish but handle them one by one as soon as they return:

 axios.get('/get/schedules') .then(response => { const schedules = response.data; schedules.forEach(schedule => axios.get(schedule.selfUri) .then(responseArray => { this.setState({ .... }) }); ) })