how to async/await redux-thunk actions?

Question

action.js

export function getLoginStatus() {
  return async(dispatch) => {
    let token = await getOAuthToken();
    let success = await verifyToken(token);
    if (success == true) {
      dispatch(loginStatus(success));
    } else {
      console.log("Success: False");
      console.log("Token mismatch");
    }
    return success;
  }
}

component.js

  componentDidMount() {
    this.props.dispatch(splashAction.getLoginStatus())
      .then((success) => {
        if (success == true) {
          Actions.counter()
        } else {
          console.log("Login not successfull");
        }
     });
   }

However, when I write component.js code with async/await like below I get this error:

Possible Unhandled Promise Rejection (id: 0): undefined is not a function (evaluating 'this.props.dispatch(splashAction.getLoginStatus())')

component.js

  async componentDidMount() {
     let success = await this.props.dispatch(splashAction.getLoginStatus());
     if (success == true) {
       Actions.counter()
     } else {
       console.log("Login not successfull");
     }
   }

How do I await a getLoginStatus() and then execute the rest of the statements? Everything works quite well when using .then(). I doubt something is missing in my async/await implementation. trying to figure that out.

did you ever get this pattern worked out? if so could you post the answer here? — ajonno, Jul 22 '17 at 01:39
Why are you waiting for a promise in a redux connected react component? This is breaking the data uni direction pattern — Aaron, Sep 03 '17 at 10:27

score 72 · Answer 1 · edited Oct 22 '20 at 03:11

The Promise approach

export default function createUser(params) {
  const request = axios.post('http://www...', params);

  return (dispatch) => {
    function onSuccess(success) {
      dispatch({ type: CREATE_USER, payload: success });
      return success;
    }
    function onError(error) {
      dispatch({ type: ERROR_GENERATED, error });
      return error;
    }
    request.then(success => onSuccess, error => onError);
  };
}

The async/await approach

export default function createUser(params) {  
  return async dispatch => {
    function onSuccess(success) {
      dispatch({ type: CREATE_USER, payload: success });
      return success;
    }
    function onError(error) {
      dispatch({ type: ERROR_GENERATED, error });
      return error;
    }
    try {
      const success = await axios.post('http://www...', params);
      return onSuccess(success);
    } catch (error) {
      return onError(error);
    }
  }
}

Referenced from the Medium post explaining Redux with async/await: https://medium.com/@kkomaz/react-to-async-await-553c43f243e2

Why `return success` or `return error`? Redux doesn't seem to use these? — corysimmons, Feb 19 '18 at 04:46
I'm not sure if the behavior in both examples are the same. In the Promise approach, an exception inside the `onSuccess` call would not be caught. In async/await approach, an exception inside the `onSuccess` call would be caught. This `onSuccess` call wraps all the redux state-change and the react re-render, any error resulted in this code would be swallowed. They talked about this here: https://github.com/facebook/react/issues/6895 — lmcarreiro, Jul 31 '18 at 16:18

score 11 · Answer 2 · answered Feb 19 '18 at 05:20

Remixing Aspen's answer.

import axios from 'axios'

import * as types from './types'

export function fetchUsers () {
  return async dispatch => {
    try {
      const users = await axios
        .get(`https://jsonplaceholder.typicode.com/users`)
        .then(res => res.data)

      dispatch({
        type: types.FETCH_USERS,
        payload: users,
      })
    } catch (err) {
      dispatch({
        type: types.UPDATE_ERRORS,
        payload: [
          {
            code: 735,
            message: err.message,
          },
        ],
      })
    }
  }
}

import * as types from '../actions/types'

const initialErrorsState = []

export default (state = initialErrorsState, { type, payload }) => {
  switch (type) {
    case types.UPDATE_ERRORS:
      return payload.map(error => {
        return {
          code: error.code,
          message: error.message,
        }
      })

    default:
      return state
  }
}

This will allow you to specify an array of errors unique to an action.

score 5 · Answer 3 · answered Apr 15 '19 at 06:15

Another remix for async await redux/thunk. I just find this a bit more maintainable and readable when coding a Thunk (a function that wraps an expression to delay its evaluation ~ redux-thunk )

actions.js

import axios from 'axios'
export const FETCHING_DATA = 'FETCHING_DATA'
export const SET_SOME_DATA = 'SET_SOME_DATA'

export const myAction = url => {
  return dispatch => {
    dispatch({
      type: FETCHING_DATA,
      fetching: true
    })
    getSomeAsyncData(dispatch, url)
  }
}

async function getSomeAsyncData(dispatch, url) {
  try {
    const data = await axios.get(url).then(res => res.data)
    dispatch({
      type: SET_SOME_DATA,
      data: data
    })
  } catch (err) {
    dispatch({
      type: SET_SOME_DATA,
      data: null
    })
  }
  dispatch({
    type: FETCHING_DATA,
    fetching: false
  })
}

reducers.js

import { FETCHING_DATA, SET_SOME_DATA } from './actions'

export const fetching = (state = null, action) => {
  switch (action.type) {
    case FETCHING_DATA:
      return action.fetching
    default:
      return state
  }
}

export const data = (state = null, action) => {
  switch (action.type) {
    case SET_SOME_DATA:
      return action.data
    default:
      return state
  }
}

score -1 · Answer 4 · answered Aug 04 '17 at 21:55

Possible Unhandled Promise Rejection

Seems like you're missing the .catch(error => {}); on your promise. Try this:

componentDidMount() {
    this.props.dispatch(splashAction.getLoginStatus())
        .then((success) => {
            if (success == true) {
                Actions.counter()
            } else {
                console.log("Login not successfull");
            }
        })
        .catch(err => {
            console.error(err.getMessage());
        }) ;
}

score -1 · Answer 5 · answered Feb 07 '22 at 08:35

-1

use dispatch(this.props.splashAction.getLoginStatus()) instead this.props.dispatch(splashAction.getLoginStatus())

answered Feb 07 '22 at 08:35

Roman

1

It is helpful to explain the changes you suggest in answers, please expand your answer, don't make it just "do this" or "try this" – YakovL Feb 07 '22 at 15:50

how to async/await redux-thunk actions?

5 Answers5

actions.js

reducers.js

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