[英]React-Redux: How do I populate a component's prop on load with data from an async call?
我有這個自動完成組件,它需要一個術語數組作為dataSource屬性。 我要輸入的數據駐留在公共API中,我已經按照此處的教程操作,以獲取以下代碼。 但是本教程(以及其他許多教程)介紹了如何將這些動作綁定到事件,而我想用頁面加載數據填充此道具。 我將如何去做?
actions.js
import fetch from 'isomorphic-fetch';
export function loadSchools(termId) {
return {
type: 'LOAD_SCHOOLS',
termId
};
}
export function receiveSchools(termId, json) {
return {
type: 'RECEIVE_SCHOOLS',
termId,
schools: json.data.children.map(child => child.data), // ???
receivedAt: Date.now()
};
}
export function getSchools(termId) {
return function (dispatch) {
dispatch(loadSchools(termId));
return fetch('http://www.northwestern.edu/class-descriptions/4650/index-v2.json')
.then(response => {
if (response.status >= 400) {
throw new Error('Bad response from server');
}
return response.json();
})
.then(data => dispatch(receiveSchools(termId, data)));
};
}
reducers.js
const initialState = {
schoolsData: {
isFetching: false,
lastUpdated: 0,
schools: []
}
};
function schools(state = initialState, action) {
switch (action.type) {
case 'LOAD_SCHOOLS':
return {
...state,
isFetching: true
};
case 'RECEIVE_SCHOOLS':
return {
...state,
isFetching: false,
schools: action.schools,
lastUpdated: receivedAt
}
default:
return state;
}
}
export default schools;
Search.jsx
import React from 'react';
import AutoComplete from 'material-ui/AutoComplete';
export default class Search extends React.Component {
render() {
return (
<AutoComplete
hintText="Search for something."
dataSource={this.props.searchdata}
maxSearchResults={15}
filter={AutoComplete.caseInsensitiveFilter}
onNewRequest={}
/>
);
}
}
Search.propTypes = {
searchdata: React.PropTypes.array.isRequired,
onSelect: React.PropTypes.func
};
index.jsx
import 'babel-polyfill';
import React from 'react';
import ReactDOM from 'react-dom';
import getMuiTheme from 'material-ui/styles/getMuiTheme';
import MuiThemeProvider from 'material-ui/styles/MuiThemeProvider';
import { grey500, white, fullBlack } from 'material-ui/styles/colors';
import { fade } from 'material-ui/utils/colorManipulator';
import { Provider } from 'react-redux';
import { createStore, applyMiddleware } from 'redux';
import thunkMiddleware from 'redux-thunk';
import schools from './reducers/reducers';
import colors from './colors';
import NavBar from './components/NavBar.jsx';
import Serif from './components/Serif.jsx';
const store = createStore(schools, applyMiddleware(thunkMiddleware));
const muiTheme = getMuiTheme({
palette: {
primary1Color: colors.northwesternPurple,
primary2Color: colors.northwesternPurple120,
primary3Color: grey500,
accent1Color: colors.northwesternPurple30,
accent2Color: colors.richBlack10,
accent3Color: colors.richBlack50,
textColor: colors.richBlack80,
alternateTextColor: white,
canvasColor: white,
borderColor: colors.richBlack20,
disabledColor: fade(colors.richBlack80, 0.3),
pickerHeaderColor: colors.northwesternPurple,
clockCircleColor: fade(colors.richBlack80, 0.07),
shadowColor: fullBlack
}
});
class App extends React.Component {
render() {
return (
<Provider store={store}>
<MuiThemeProvider muiTheme={muiTheme}>
<div> {/* MuiThemeProvider requires stricly one child element */}
<NavBar />
<Serif /> {/* This component contains SearchContainer, which in turn contains Search */}
</div>
</MuiThemeProvider>
</Provider>
);
}
}
ReactDOM.render(<App />, document.getElementById('app'));
您可以從另一個組件渲染Search組件,我們稱其為SearchContainer 。 SearchContainer由react-redux的connect函數裝飾,該函數僅具有分派動作以獲取學校的作用。 在獲取學校之前, SearchContainer不會呈現搜索組件。
這是代碼示例的示例。 在這里,我假設您不使用react-redux 。
首先,您在reducers.js的初始狀態中有一個小問題。 它應該是:
const initialState = {
isFetching: false,
lastUpdated: 0,
schools: []
};
function schools(state = initialState, action) {
switch (action.type) {
case 'LOAD_SCHOOLS':
return {
...state,
isFetching: true
};
case 'RECEIVE_SCHOOLS':
return {
...state,
isFetching: false,
schools: action.schools,
lastUpdated: receivedAt
}
default:
return state;
}
}
SearchContainer.js
// ./containers/SearchContainer.js
import React, { Component } from 'react';
import { connect } from 'react-redux';
import { loadSchools } from '../actions/actions'
import Search from '../components/Search';
class SearchContainer extends Component {
componentDidMount() {
this.props.loadSchools(this.props.termId);
},
render() {
const {
schools,
isFetching
} = this.props;
if (isFetching) {
return null;
}
return <Search schools={schools} />;
}
}
const mapStateToProps = (state) => ({
isFetching: state.isFetching,
schools: state.schools
});
const mapActionsToProps = (dispatch) => ({
loadSchools: (termId) => dispatch(loadSchools(termId)),
});
export default connect(mapStateToProps, mapActionsToProps)(SearchContainer);
這樣,在第一次渲染時,不會渲染您的Search組件。 僅在加載學校之后才渲染它。
您可以從componentDidMount生命周期方法(可能在您的Serif組件中,但我看不到該代碼)中調度LOAD_SCHOOLS操作。
從文檔:
掛載組件后立即調用componentDidMount() 。 需要DOM節點的初始化應在此處進行。 如果您需要從遠程端點加載數據,那么這是實例化網絡請求的好地方 。 在此方法中設置狀態將觸發重新渲染。
https://facebook.github.io/react/docs/react-component.html#componentdidmount
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.