React/redux application uses async/await

async/await

Async/await is a new feature of the ES7 standard that has not yet been officially announced. In short, you'll want to write asynchronous code in a synchronized way. For the front-end, the writing of asynchronous task code has gone through the callback to the current Promise and will eventually evolve into async/await. Although this feature has not yet been officially released, the use of Babel Polyfill we can already use it in the application.

Http://www.tuicool.com/articles/B77zAbe

Now assuming a simple react/redux application, I'll introduce async/await to its code. Actions

In this example, there is an Action to create a new article, the traditional method is to use Promise combined with redux-thunk middleware implementation.

Import Axios from ' Axios '

export default function createpost (params) {  
    Const success = (Result) => {
        Dispa TCH ({
            type: ' create_post_success ',
            payload:result
        }) return result
    }

    Const FAIL = (ERR) = > {
        dispatch ({
            type: ' Create_post_fail ',
            err
        }) return
        err
    } return

    dispatch = > {return
        axios.post (' http://xxxxx ', params)
        . Then (success)
        . catch (fail)
    }
}

Now rewrite it as a async/await implementation:

Import Axios from ' Axios '

export default function createpost (params) {  
    Const success = (Result) => {
        Dispa TCH ({
            type: ' create_post_success ',
            payload:result
        }) return result
    }

    Const FAIL = (ERR) = > {
        dispatch ({
            type: ' Create_post_fail ',
            err
        }) return
        err
    } return

    Async Dispatch => {
        try {
            const result = await axios.post (' http://xxxxx ', params) return
            success (result) c19/>} catch (Err) {return
            fail (ERR)}}}

Async and await are used in pairs, and are characterized by making the code look like the synchronized code. Components

Also, in the react component, compare the similarities and differences between the Promise and Async/await methods.

Traditionally used Promise:

import React, { Component } from 'react'  
import { connect } from 'react-redux'  
import { createPost } from '../actions/post'

class PostEditForm extends Component {  
    constructor(props) {
        super(props)
    }

    contributePost = e => {
        e.preventDefault()

        // .... get form values as params

        this.props.createPost(params)
        .then(response => {
            // show success message
        })
        .catch(err => {
            // show error tips
        })
    }

    render () {
        return (
            <form onSubmit={this.contributePost}>
                <input name="title"/>
                <textarea name="content"/>
                <button>Create</button>
            </form>
        )
    }
}

export default connect(null, dispatch => {  
    return {
        createPost: params => dispatch(createPost(params))
    }
})(PostEditForm)

If you use async/await

import React, { Component } from 'react'  
import { connect } from 'react-redux'  
import { createPost } from '../actions/post'

class PostEditForm extends Component {  
    constructor(props) {
        super(props)
    }

    async contributePost = e => {
        e.preventDefault()

        // .... get form values as params

        try {
            const result = await this.props.createPost(params)
            // show success message
        } catch (err) {
            // show error tips
        }
    }

    render () {
        return (
            <form onSubmit={this.contributePost}>
                <input name="title"/>
                <textarea name="content"/>
                <button>Create</button>
            </form>
        )
    }
}

export default connect(null, dispatch => {  
    return {
        createPost: params => dispatch(createPost(params))
    }
})(PostEditForm)

The

can be seen, the two patterns, async\await  more intuitive and concise, is the future trend. But at present, it is also necessary to use the Babel  transform-async-to-module-method  plug-in to convert its browser-supported syntax, although there is no performance improvement, but for code authoring experience is better.