在componentDidMount内部处理多个axios获取请求

Question

I have a React component like this:

class Example extends Component {
   constructor(props) {
     super(props);

     this.state = {
       name: '',
       address: '',
       phone: ''
     }
   }

   componentDidMount() {
     //APIcall1 to get name and set the state
     //i.e., axios.get().then(this.setState())
     //APIcall2 to get address and set the state
     //APIcall3 to get phone and set the state
    }
 }`

As you can see I am making three API get requests to get the details and setting the state three times after getting the data. Due to this, I am getting this error:

Warning: Cannot update during an existing state transition (such as within render or another component's constructor). Render methods should be a pure function of props and state; constructor side-effects are an anti-pattern, but can be moved to componentWillMount .

By the way, I am not causing a state change in the render method. Anyway to solve this issue?

Answer 1

As axios.get returns a promise, you can link them together before calling setState. For example using Promise.all :

componentDidMount() {
  Promise.all([
    APIcall1, // i.e. axios.get(something)
    APIcall2,
    APIcall3
  ]).then(([result1, result2, result3]) => {
    // call setState here
  })
}

Just beware that if any of the api calls fail, Promise.all will catch, and setState won't be called.

Answer 2

In axios you have the method axios.all :

function getUserAccount() {
  return axios.get('/user/12345');
}

function getUserPermissions() {
  return axios.get('/user/12345/permissions');
}

axios.all([getUserAccount(), getUserPermissions()])
  .then(axios.spread(function (acct, perms) {
    // Both requests are now complete
  }));

Or you can use the standard Promise.all :

function getUserAccount() {
  return axios.get('/user/12345');
}

function getUserPermissions() {
  return axios.get('/user/12345/permissions');
}

Promise.all([getUserAccount(), getUserPermissions()])
  .then(data => {
    // Both requests are now complete
  });