How to set initialValues based on async source such as an ajax call with redux-form

Question

On the official pages and in the GitHub issues for redux-form there are more than one example of how to work with initialValues however I cannot find a single one that focuses on explaining how initialValues can be set in response to an asynchronous source.

The main case that I have in mind is something like a simple CRUD application where a user is going to edit some entity that already exists. When the view is first opened and the redux-form component is mounted but before the component is rendered the initialValues must be set. Lets say that in this example that the data is loaded on demand when the component is first mounted and rendered for the first time. The examples show setting initialValues based on hard coded values or the redux store state but none that I can find focus on how to set the initialValues based on something async like a call to XHR or fetch.

I'm sure I'm just missing something fundamental so please point me in the right direction.

References:

• Initializing Form State
• Handling form defaults
• What is the correct way to populate a dynamic form with initial data?

Answer 1

use this :

UpdateUserForm = reduxForm({
  enableReinitialize: true,
  destroyOnUnmount: false,
  form: 'update_user_form' // a unique identifier for this form
})(UpdateUserForm);

UpdateUserForm = connect(
  (state) => ({
    initialValues: state.userManagment.userSingle
  })
)(UpdateUserForm);
export default UpdateUserForm;

Answer 2

Here is minimal working example on how to set initialValues based on async source.
It uses initialize action creator.

All values from initialValues shouldn't be undefined, or you will get an infinite loop.

// import { Field, reduxForm, change, initialize } from 'redux-form';

async someAsyncMethod() {
  // fetch data from server
  await this.props.getProducts(),

  // this allows to get current values of props after promises and benefits code readability
  const { products } = this.props;

  const initialValues = { productsField: products };

  // set values as pristine to be able to detect changes
  this.props.dispatch(initialize(
    'myForm',
    initialValues,
  ));
}

Answer 3

EDIT: Updated Solution from ReduxForm docs

This is now documented in the latest version of ReduxForm, and is much simpler than my previous answer.

The key is to connect your form component after decorating it with ReduxForm. Then you will be able to access the initialValues prop just like any other prop on your component.

// Decorate with reduxForm(). It will read the initialValues prop provided by connect()
InitializeFromStateForm = reduxForm({
  form: 'initializeFromState'
})(InitializeFromStateForm)

// now set initialValues using data from your store state
InitializeFromStateForm = connect(
  state => ({
    initialValues: state.account.data 
  })
)(InitializeFromStateForm)

---

I accomplished this by using the redux-form reducer plugin method.

The following demos fetching async data and pre-populating a user form with response.

const RECEIVE_USER = 'RECEIVE_USER';

// once you've received data from api dispatch action
const receiveUser = (user) => {
    return {
       type: RECEIVE_USER,
       payload: { user }
    }
}

// here is your async request to retrieve user data
const fetchUser = (id) => dispatch => {
   return fetch('http://getuser.api')
            .then(response => response.json())
            .then(json => receiveUser(json));
}

Then in your root reducer where you include your redux-form reducer you would include your reducer plugin that overrides the forms values with the returned fetched data.

const formPluginReducer = {
   form: formReducer.plugin({
      // this would be the name of the form you're trying to populate
      user: (state, action) => {
         switch (action.type) {
             case RECEIVE_USER:
                return {
                  ...state,
                  values: {
                      ...state.values,
                      ...action.payload.user
                  }
               }
            default:
               return state;
         }
      }
   })
};

const rootReducer = combineReducers({
   ...formPluginReducer,
   ...yourOtherReducers
});

Finally you include you combine your new formReducer with the other reducers in your app.

Note The following assumes that the fetched user object's keys match the names of the fields in the user form. If this is not the case you will need to perform an additional step on the data to map fields.

Answer 4

While this method may not be the best solution, it works well enough for my needs:

• AJAX request to API on entry
• Initializes form with data when request has been fulfilled or displays a server error
• Resetting form will still reset to initial seed data
• Allows the form to be reused for other purposes (for example, a simple if statement could bypass setting initial values): Add Post and Edit Post or Add Comment and Edit Comment...etc.
• Data is removed from Redux form on exit (no reason to store new data in Redux since it's being re-rendered by a Blog component)

Form.jsx:

import React, { Component } from 'react';
import { Field, reduxForm } from 'redux-form';
import { connect } from 'react-redux';
import { browserHistory, Link } from 'react-router';

import { editPost, fetchPost } from '../../actions/BlogActions.jsx';
import NotFound from '../../components/presentational/notfound/NotFound.jsx';
import RenderAlert from '../../components/presentational/app/RenderAlert.jsx';   
import Spinner from '../../components/presentational/loaders/Spinner.jsx'; 

// form validation checks
const validate = (values) => {
  const errors = {}
  if (!values.title) {
    errors.title = 'Required';
  }

  if (!values.image) {
    errors.image = 'Required';
  }

  if (!values.description) {
    errors.description = 'Required';
  } else if  (values.description.length > 10000) {
    errors.description = 'Error! Must be 10,000 characters or less!';
  }

  return errors;
}

// renders input fields
const renderInputField = ({ input, label, type, meta: { touched, error } }) => (
  <div>
    <label>{label}</label>
    <div>
      <input {...input} className="form-details complete-expand" placeholder={label} type={type}/>
      {touched && error && <div className="error-handlers "><i className="fa fa-exclamation-triangle" aria-hidden="true"></i> {error}</div>}
    </div>
  </div>
)

// renders a text area field
const renderAreaField = ({ textarea, input, label, type, meta: { touched, error } }) => (
  <div>
    <label>{label}</label>
    <div>
      <textarea {...input} className="form-details complete-expand" placeholder={label} type={type}/>
      {touched && error && <div className="error-handlers"><i className="fa fa-exclamation-triangle" aria-hidden="true"></i> {error}</div>}
    </div>
  </div>
)

class BlogPostForm extends Component {   
  constructor() {
    super();

    this.state = {
      isLoaded: false,
      requestTimeout: false,
    };
  }

  componentDidMount() {
    if (this.props.location.query.postId) {
      // sets a 5 second server timeout
      this.timeout = setInterval(this.timer.bind(this), 5000);
      // AJAX request to API 
      fetchPost(this.props.location.query.postId).then((res) => {
        // if data returned, seed Redux form
        if (res.foundPost) this.initializeForm(res.foundPost);
        // if data present, set isLoaded to true, otherwise set a server error
        this.setState({
          isLoaded: (res.foundPost) ? true : false,
          serverError: (res.err) ? res.err : ''
        });
      });
    }
  }

  componentWillUnmount() {
    this.clearTimeout();
  }

  timer() {
    this.setState({ requestTimeout: true });
    this.clearTimeout();
  }

  clearTimeout() {
    clearInterval(this.timeout);
  }

  // initialize Redux form from API supplied data
  initializeForm(foundPost) {

    const initData = {
      id: foundPost._id,
      title: foundPost.title,
      image: foundPost.image,
      imgtitle: foundPost.imgtitle,
      description: foundPost.description
    }

    this.props.initialize(initData);
  }

  // onSubmit => take Redux form props and send back to server
  handleFormSubmit(formProps) {
    editPost(formProps).then((res) => {
      if (res.err) {
        this.setState({
          serverError: res.err
        });
      } else {
        browserHistory.push(/blog);
      }
    });
  }

  renderServerError() {
    const { serverError } = this.state;
    // if form submission returns a server error, display the error
    if (serverError) return <RenderAlert errorMessage={serverError} />
  }

  render() {
    const { handleSubmit, pristine, reset, submitting, fields: { title, image, imgtitle, description } } = this.props;
    const { isLoaded, requestTimeout, serverError } = this.state;

    // if data hasn't returned from AJAX request, then render a spinner 
    if (this.props.location.query.postId && !isLoaded) {
      // if AJAX request returns an error or request has timed out, show NotFound component
      if (serverError || requestTimeout) return <NotFound />

      return <Spinner />
     }

    // if above conditions are met, clear the timeout, otherwise it'll cause the component to re-render on timer's setState function
    this.clearTimeout();

    return (
      <div className="col-sm-12">
        <div className="form-container">
          <h1>Edit Form</h1>
          <hr />
          <form onSubmit={handleSubmit(this.handleFormSubmit.bind(this))}>
            <Field name="title" type="text" component={renderInputField} label="Post Title" />
            <Field name="image" type="text" component={renderInputField} label="Image URL" />
            <Field name="imgtitle" component={renderInputField} label="Image Description" />
            <Field name="description" component={renderAreaField} label="Description" />
            <div>
              <button type="submit" className="btn btn-primary partial-expand rounded" disabled={submitting}>Submit</button>
              <button type="button" className="btn btn-danger partial-expand rounded f-r" disabled={ pristine || submitting } onClick={ reset }>Clear Values</button>
            </div>
          </form>
         { this.renderServerError() }
        </div>
      </div>
    )
  }
}

BlogPostForm = reduxForm({
  form: 'BlogPostForm',
  validate,
  fields: ['name', 'image', 'imgtitle', 'description']
})(BlogPostForm);


export default BlogPostForm = connect(BlogPostForm);

BlogActions.jsx:

import * as app from 'axios';

const ROOT_URL = 'http://localhost:3001';

// submits Redux form data to server
export const editPost = ({ id, title, image, imgtitle, description, navTitle }) => {
 return app.put(`${ROOT_URL}/post/edit/${id}?userId=${config.user}`, { id, title, image, imgtitle, description, navTitle }, config)
 .then(response => {
   return { success: response.data.message }
  })
  .catch(({ response }) => {
    if(response.data.deniedAccess) {
      return { err: response.data.deniedAccess }
    } else {
      return { err: response.data.err }
    }
  });
}

// fetches a single post from the server for front-end editing     
export const fetchPost = (id) => {
  return app.get(`${ROOT_URL}/posts/${id}`)
  .then(response => {
     return { foundPost: response.data.post}
   })
   .catch(({ response }) => {
     return { err: response.data.err };
   });
}    

RenderAlert.jsx:

import React, { Component } from 'react';

const RenderAlert = (props) => {   
    const displayMessage = () => {
      const { errorMessage } = props;

      if (errorMessage) {
        return (
          <div className="callout-alert">
            <p>
              <i className="fa fa-exclamation-triangle" aria-hidden="true"/>
              <strong>Error! </strong> { errorMessage }
            </p>
          </div>
        );
      }
    }

    return (
      <div>
        { displayMessage() }
      </div>
    );
  }


export default RenderAlert;

Reducers.jsx

import { routerReducer as routing } from 'react-router-redux';
import { reducer as formReducer } from 'redux-form';
import { combineReducers } from 'redux';  

const rootReducer = combineReducers({
  form: formReducer,
  routing
});

export default rootReducer;

Answer 5

By default, you may only initialize a form component once via initialValues. There are two methods to reinitialize the form component with new "pristine" values:

Pass a enableReinitialize prop or reduxForm() config parameter set to true to allow the form the reinitialize with new "pristine" values every time the initialValues prop changes. To keep dirty form values when it reinitializes, you can set keepDirtyOnReinitialize to true. By default, reinitializing the form replaces all dirty values with "pristine" values.

Dispatch the INITIALIZE action (using the action creator provided by redux-form).

Referenced from : http://redux-form.com/6.1.1/examples/initializeFromState/

Answer 6

Could you fire the dispatch on componentWillMount(), and set the state to loading.

While it is loading, render a spinner for example and only when the request returns with the values, update the state, and then re-render the form with the values??