[英]Updating Redux store from external API
我目前正在使用 Redux 作为数据管理系统在 React 中构建一个应用程序。 我遇到了一个问题,我需要在从 web 套接字发送事件时更新应用程序(网页)中的组件。 流程如下:
API Server push change -> Redux action is called -> Component that is effected by this update, is rebuild/re rendered.
但是流程的中间和最后部分是我迷失的地方。 调用操作时不会重新创建/重新呈现仪表板。
我对 React 和 Redux 完全陌生。
商店.js
import { applyMiddleware, createStore } from 'redux';
import {createLogger} from "redux-logger";
import thunk from 'redux-thunk'
import promise from 'redux-promise-middleware'
import reducers from './reducers';
const middleware = applyMiddleware(promise(), thunk, createLogger());
export default createStore(reducers, middleware);
DashboardReducer.js
const initState = {
dashboard: [],
fetching: false,
fetched: false,
error: null
}
export default function reducer(state = initState, action) {
switch (action.type) {
case "FETCH_DASHBOARD":
{
return {
...state,
fetching: true
}
}
case 'FETCH_DASHBOARD_REJECTED':
{
return {
...state,
fetching: false,
error: action.payload
}
}
case 'FETCH_DASHBOARD_FULFILLED':
{
return {fetching: false, fetched: true, dashboard:action.payload.dashboard}
}
case 'UPDATEING_SYSTEM':
{
return Object.assign({}, state, {dashboard: action.payload.dashboard});
}
default:
break;
}
return state;
}
DashboardActions.js
import io from 'socket.io-client'
import UniversalCookie from 'universal-cookie';
const cookies = new UniversalCookie();
//CHANGE URL FOR PRODUCTION
//-----------------------------------------
const socket = io.connect('http://localhost:8080');
//-----------------------------------------
export function fetchDashboard() {
return function(dispatch) {
socket.emit("get dashboard", {cookie:cookies.get("**********")});
socket.on("return dashboard", function(jDashboard) {
dispatch({
type: 'FETCH_DASHBOARD_FULFILLED',
payload: {
dashboard: jDashboard.dashboard
}
});
});
socket.on("errored", function(data) {
console.log(data);
dispatch({type: 'FETCH_DASHBOARD_REJECTED', payload: data});
});
socket.on("updating systems", function(data) {
console.log("updating...", data);
dispatch({
type: 'UPDATEING_SYSTEMS',
payload: {
dashboard: data.updatedSystems
}
});
});
}
}
仪表板组件
import React, {Component} from 'react';
import './Dashboard.css';
import CollectionContainer from '../CollectionContainer/CollectionContainer';
import {fetchDashboard} from '../../actions/dashboardAction';
import {connect} from "react-redux";
@connect((store) => {
return {dashboard: store.dashboardReducer.dashboard};
})
export default class Dashboard extends Component {
componentWillMount() {
this.props.dispatch(fetchDashboard());
}
render() {
return (
<div className="App">
<div className="Head">HEADER</div>
<div className="CollectionContainer">
<CollectionContainer dashboard={this.props.dashboard}/>
</div>
</div>
);
}
}
我认为问题出在减速器上,但我不确定。
最佳方案是仅更新受影响状态的子对象。 截至目前,状态的整个仪表板道具都发生了变化。
更新
我现在对代码进行了一些修改,并更改了后端服务器以提供更多数据,以便更容易找到我需要更改的“系统”。 现在是实际改变状态的问题..这就是我现在所拥有的
DashboardReducer.js
const initState = {
dashboard: [],
fetching: false,
fetched: false,
error: null
}
export default function reducer(state = initState, action) {
switch (action.type) {
case "FETCH_DASHBOARD":
return {
...state,
fetching: true
}
case 'FETCH_DASHBOARD_REJECTED':
return {
...state,
fetching: false,
error: action.payload
}
case 'FETCH_DASHBOARD_FULFILLED':
return {fetching: false, fetched: true, dashboard: action.payload.dashboard}
case 'UPDATEING_SYSTEM':
let shelveNr = action.payload.dashboard[0].shelve;
let collectionNr = action.payload.dashboard[0].collection;
let systemNr = action.payload.dashboard[0].system;
let status = action.payload.dashboard[0].status;
console.log(" Status: ", state.dashboard[shelveNr]);
let newState = Object.assign({}, state, {
...state.dashboard[shelveNr].Collections[collectionNr].systems[systemNr].status,
status: status
});
return newState;
default:
return state;
}
}
但是,您的操作类型为'UPDATEING_SYSTEMS'
,在您的减速器中,您有'UPDATEING_SYSTEM'
。 此外,您不需要大括号。
更新你的减速器,这样的case
是
case 'UPDATEING_SYSTEMS':
return Object.assign({}, state, {dashboard: action.payload.dashboard});
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