javascript - 根据登录状态使用 React-Native-Router-Flux 显示不同的组件

Question

我的应用正在使用 react-native-router-flux根据用户是否是

• 登录，或等待应用连接到后端(显示<Loading />)
• 登录(显示<Home />)
• 未登录(显示<Welcome />)

实现该目标的推荐方法是什么？

这个例子很完美，只是它没有使用 react-native-router-flux .无论如何修改代码以使用react-native-router-flux ？

在我下面的尝试中，调用 Actions.loading()在 render 之前调用函数会出错，因为 Actions尚未定义。可以if在 render 之后调用语句功能？

此外，每次 Prop 更新时，都会导致重新渲染 App ，给出关于场景键如何已经存在的错误。

import React, { Component } from 'react';
import Meteor, { createContainer } from 'react-native-meteor';
import { Actions } from 'react-native-router-flux';

import Home from './components/home';
import Welcome from './components/welcome';
import Loading from './components/loading';
import settings from './config/settings';


Meteor.connect(settings.METEOR_URL);


const App = (props) => {

    const { status, user, loggingIn } = props;

    if (status.connected == false || loggingIn) {
        // Render <Loading />
        Actions.loading();
    } else if (user !== null) {
        // Render <Home />
        Actions.home();
    } else {
        // Render <Welcome />
        Actions.welcome();
    }

    return (
        <Router>
            <Scene key="root">
                <Scene key="home" component={Home} title="Home" hideNavBar={true} />
                <Scene key="welcome" component={Welcome} title="Welcome" hideNavBar={true} />
                <Scene key="loading" component={Loading} title="Loading" hideNavBar={true} />
            </Scene>
        </Router>
    )
}


export default createContainer(() => {
    return {
        status: Meteor.status(),
        user: Meteor.user(),
        loggingIn: Meteor.loggingIn()
    };
}, App)

---

使用 Dispatch 的问题组件

根据 abeikverdi 的建议，我创建了以下 Dispatch包含显示组件之一的逻辑的组件 <Loading /> , <Home />或 <Welcome /> .

问题:当this.props.status.connected是true (React Native 应用程序连接到 Meteor 后端)，this.props.user总是 null在 React Native 应用程序从 Meteor 后端接收此数据之前的一段时间。但是因为它最初被评估为null , Action.welcome()将执行。 this.props.user 时，此行为不正确最终变成不null一两秒后，用户应该被重定向到 Actions.home()相反。

有什么想法吗？

export class Dispatch extends Component {
    constructor(props) {
        super(props);
    }

    componentWillUpdate() {
        if(this.props.status.connected == false) {
            Actions.loading();
        } else {
            console.log('meteor.user(): ', Meteor.user())
            if (this.props.user !== null) {
                Actions.home();
            } else {
                Actions.welcome();
            }
        }
    }

    render() {
        return (
            <View></View>
        )
    }
}


export default createContainer(() => {
    return {
        status: Meteor.status(),
        user: Meteor.user(),
        loggingIn: Meteor.loggingIn()
    };
}, Dispatch);

---

日志中的错误/警告 react-native log-android

以下是 React Native 应用启动一段时间后，通过杀死 Meteor 服务器断开与 Meteor (DDP) 服务器的连接时的 Android 日志输出。

使用 console.log("<App /> render") ，似乎每当 render传递 new 后再次调用函数 props通过 meteor 的 createContainer , Key is already defined触发错误。

无论如何要摆脱这个错误/警告？

12-23 02:27:01.875 31197 19338 I ReactNativeJS: Running application "RNapp" with appParams: {"initialProps":{},"rootTag"
:1}. __DEV__ === true, development-level warning are ON, performance optimizations are OFF
12-23 02:27:01.891 31197 19338 I ReactNativeJS: render
12-23 02:27:01.995 31197 19338 I ReactNativeJS: Connected to DDP server.
12-23 02:27:01.999 31197 19338 I ReactNativeJS: Connected to DDP server.
12-23 02:27:02.012 31197 19338 I ReactNativeJS: render
12-23 02:27:02.013 31197 19338 I ReactNativeJS: Key home is already defined!
12-23 02:27:02.013 31197 19338 I ReactNativeJS: Key welcome is already defined!
12-23 02:27:02.013 31197 19338 I ReactNativeJS: Key loading is already defined!
12-23 02:27:02.013 31197 19338 I ReactNativeJS: Key root is already defined!
12-23 02:27:34.592 31197 19338 I ReactNativeJS: Disconnected from DDP server.
12-23 02:27:34.593 31197 19338 I ReactNativeJS: Disconnected from DDP server.
12-23 02:27:34.599 31197 19338 I ReactNativeJS: <App /> render
12-23 02:27:34.599 31197 19338 I ReactNativeJS: Key home is already defined!
12-23 02:27:34.599 31197 19338 I ReactNativeJS: Key welcome is already defined!
12-23 02:27:34.599 31197 19338 I ReactNativeJS: Key loading is already defined!
12-23 02:27:34.599 31197 19338 I ReactNativeJS: Key root is already defined!
12-23 02:27:34.609 31197 19338 I ReactNativeJS: <Loading /> render
12-23 02:27:35.603 31197 19338 I ReactNativeJS: Disconnected from DDP server.
12-23 02:27:35.613 31197 19338 I ReactNativeJS: <App /> render
12-23 02:27:35.613 31197 19338 I ReactNativeJS: Key home is already defined!
12-23 02:27:35.613 31197 19338 I ReactNativeJS: Key welcome is already defined!
12-23 02:27:35.613 31197 19338 I ReactNativeJS: Key loading is already defined!
12-23 02:27:35.613 31197 19338 I ReactNativeJS: Key root is already defined!
12-23 02:27:45.599 31197 19338 I ReactNativeJS: Disconnected from DDP server.
12-23 02:27:45.616 31197 19338 I ReactNativeJS: <App /> render
12-23 02:27:45.616 31197 19338 I ReactNativeJS: Key home is already defined!
12-23 02:27:45.616 31197 19338 I ReactNativeJS: Key welcome is already defined!
12-23 02:27:45.616 31197 19338 I ReactNativeJS: Key loading is already defined!
12-23 02:27:45.616 31197 19338 I ReactNativeJS: Key root is already defined!

App组件

export class App extends Component {

    constructor(props) {
        super(props);
    }

    componentWillReceiveProps(nextProps) {
        if (nextProps.status.connected == false) {
            Actions.loading();
        } else {
            if (nextProps.user !== null) {
                Actions.home();
            } else {
                Actions.welcome();
            }
        }
    }


    render() {
       console.log('<App /> render')
        return (
            <Router>
                <Scene key="root">
                    <Scene key="home" component={Home} title="Home" hideNavBar={true} />
                    <Scene key="welcome" component={Welcome} title="Welcome" hideNavBar={true} />
                    <Scene key="loading" component={Loading} title="Loading" hideNavBar={true} />
                    <Scene key="profile" component={Profile} title="Home" hideNavBar={true} />
                    <Scene key="history" component={History} title="Home" hideNavBar={true} />
                    <Scene key="search" component={Search} title="Home" hideNavBar={true} />
                </Scene>
            </Router>
        )       
    }

}


export default createContainer(() => {
  return {
    status: Meteor.status(),
    user: Meteor.user(),
    loggingIn: Meteor.loggingIn(),
  };
}, App);

Answer 1

您可以通过使用 initial prop 来实现这一点，您可以从存储中读取指示用户是否已登录的数据，例如使用 access_token 。

然后你使用 initial={access_token}//例如

但请记住，它会显示初始属性等于 true 的最后一个场景

// in componentDidMount
const currentUserAccessToken = store.getState().currentUserAccessToken;
        <Scene
            component={SignIn}
            hideNavBar
            initial={!currentUserAccessToken}
            key="signIn"
            title={I18n.t('sign_in')}
        />