Anche se questo metodo non può essere la soluzione migliore, funziona abbastanza bene per le mie esigenze:
- richiesta AJAX API in entrata
- Inizializza form con i dati quando richiesta è stata soddisfatta o viene visualizzato un errore del server
- Il ripristino del modulo verrà comunque reimpostato sui dati iniziali iniziali
- Consente al modulo di essere reu sed per altri scopi (ad esempio, un'istruzione if semplice potrebbe ignorare l'impostazione dei valori iniziali): Aggiungi post e modifica post o aggiungi commento e modifica commento ... ecc.
- dati vengono rimossi dal modulo Redux in uscita (nessuna ragione per memorizzare i nuovi dati in Redux dal momento che è in fase di ri-reso da un componente Blog)
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;
Questo ha funzionato per me, anche se sembra come un sacco di testo standard per un funzionamento di base. Si noti che la forma dello stato restituito dal riduttore del plugin (contenente un oggetto 'values') è importante. – ChidG
@ChidG Ho aggiornato la mia risposta con una soluzione aggiornata che ho trovato recentemente negli ultimi documenti redux-form. Molto meno piastra di caldaia, e waaaay più dritto in avanti. – ryandrewjohnson
Grazie - Ho provato quel metodo documentato, ma non ho potuto farlo funzionare. Per ora rimarrò con la soluzione 'formReducer.plugin'. – ChidG