I am trying to navigate to a certain screen on my bottom-tab-navigator when a user opens the app by clicking a notification.
Looking into the official docs Navigating without the navigation prop, my setup of my main navigator is as follows:
import {navigationRef, isReadyRef} from './root';
const MainNav = _ => {
if (isLoading) {
return isFirstTime ? (<OnBoarding />) : (<SplashScreen />);
}
return (
<NavigationContainer
ref={navigationRef}
onReady={() => {isReadyRef.current = true}}>
{!token ? <AuthNav /> : <AppNav />}
</NavigationContainer>
);
}
My root.js is as follows:
import * as React from 'react';
export const isReadyRef = React.createRef();
export const navigationRef = React.createRef();
export function navigate(name, params) {
if (isReadyRef.current && navigationRef.current) {
// Perform navigation if the app has mounted
navigationRef.current.navigate(name, params);
} else {
// You can decide what to do if the app hasn't mounted
// You can ignore this, or add these actions to a queue you can call later
console.log('Not mounted yet.')
}
}
And I had added the OneSignal event listener in my root index.js as following:
const App = _ => {
useEffect(() => {
OneSignal.addEventListener('opened', onOpened);
return () => OneSignal.removeEventListener('opened', onOpened);
}, []);
return {
<StoreProvider store={store}>
<MainNav />
</StoreProvider>
}
}
And my onOpened function is as follows:
import {navigate} from '../nav/root';
const onOpened = ({notification}) => {
if(notification.type == 'New Request'){
navigate('Notifications');
}
}
But when I test it as expected Not mounted yet. is printed to console. So I want to
add these actions to a queue you can call later
as stated by the official react navigation docs but I am not sure how to do this. I found react-native-queue but it is no longer being maintained and using a setTimeout just seems like an ugly hack cause the load time varies. So is there a better approach or solution that I can use to navigate only after the loading is done (I am thinking of using redux for this) and my navigators have been mounted (not sure how to do this)?
Related
I have an Expo app that will open some web page with a redirect to expo itself. On that case, this is to perform 3DS callbacks. Here is a very simplified version:
import React, {
FC, useEffect, useState,
} from 'react';
import * as Linking from 'expo-linking';
import * as WebBrowser from 'expo-web-browser';
import {
Button,
} from '#private/apps-components';
import {
ButtonProps,
View,
} from 'react-native';
export const MyComponent: FC = () => {
const [loading, setLoading] = useState<boolean>(false);
const urlEventHandler = async (event): Promise<void> => {
console.log('url-event', event);
setLoading(false);
// Stuff...
};
useEffect(() => {
Linking.addEventListener('url', urlEventHandler);
return () => Linking.removeEventListener('url', urlEventHandler);
}, []);
const handlePress: ButtonProps['onPress'] = () => {
setLoading(false);
WebBrowser.openBrowserAsync(aRandomUrlThatWillRedirectToTheApp, {
showInRecents: true,
})
}
return (
<View>
<Button
title="Test"
onPress={handlePress}
loading={loading}
/>
</View>
);
};
export default null;
This is working. However, if the customer close the navigator before the web redirect is being processed, the app is stuck on the loading state.
The question is: How to detect if a user has closed the opened WebBrowser?
Solved this using AppState:
https://reactnative.dev/docs/appstate
if (appState === "active") { // do things after closing the browser }
I haven't actually tested this - could follow up - but you could probably use react-navigation to detect whether the component is in focus or not. IE when you open the web browser, the component is not in focus, but when you close the web browser, the component is back in focus.
For react navigation version 4 you would wrap the component in withNavigationFocus in order to achieve this: https://reactnavigation.org/docs/4.x/function-after-focusing-screen#triggering-an-action-with-the-withnavigationfocus-higher-order-component. For 5, and 5+, you can use the useIsFocused hook: https://reactnavigation.org/docs/5.x/function-after-focusing-screen/#re-rendering-screen-with-the-useisfocused-hook
I'm new to React Native, and my understanding is that functional components and hooks are the way to go. What I'm trying to do I've boiled down to the simplest case I can think of, to use as an example. (I am, by the way, writing in TypeScript.)
I have two Independent components. There is no parent-child relationship between the two. Take a look:
The two components are a login button on the navigation bar and a switch in the enclosed screen. How can I make the login button be enabled when the switch is ON and disabled when the switch is OFF?
The login button looks like this:
const LoginButton = (): JSX.Element => {
const navigation = useNavigation();
const handleClick = () => {
navigation.navigate('Away');
};
// I want the 'disabled' value to update based on the state of the switch.
return (
<Button title="Login"
color="white"
disabled={false}
onPress={handleClick} />
);
};
As you can see, right now I've simply hard-coded the disabled setting for the button. I'm thinking that will no doubt change to something dynamic.
The screen containing the switch looks like this:
const HomeScreen = () => {
const [isEnabled, setEnabled] = useState(false);
const toggleSwitch = () => setEnabled(value => !value);
return (
<SafeAreaView>
<Switch
style={styles.switch}
ios_backgroundColor="#3e3e3e"
onValueChange={toggleSwitch}
value={isEnabled}
/>
</SafeAreaView>
);
};
What's throwing me for a loop is that the HomeScreen and LoginButton are setup like this in the navigator stack. I can think of no way to have the one "know" about the other:
<MainStack.Screen name="Home"
component={HomeScreen}
options={{title: "Home", headerRight: LoginButton}} />
I need to get the login button component to re-render when the state of the switch changes, but I cannot seem to trigger that. I've tried to apply several different things, all involving hooks of some kind. I have to confess, I think I'm missing at least the big picture and probably some finer details too.
I'm open to any suggestion, but really I'm wondering what the simplest, best-practice (or thereabouts) solution is. Can this be done purely with functional components? Do I have to introduce a class somewhere? Is there a "notification" of sorts (I come from native iOS development). I'd appreciate some help. Thank you.
I figured out another way of tracking state, for this simple example, that doesn't involve using a reducer, which I'm including here for documentation purposes in hopes that it may help someone. It tracks very close to the accepted answer.
First, we create both a custom hook for the context, and a context provider:
// FILE: switch-context.tsx
import React, { SetStateAction } from 'react';
type SwitchStateTuple = [boolean, React.Dispatch<SetStateAction<boolean>>];
const SwitchContext = React.createContext<SwitchStateTuple>(null!);
const useSwitchContext = (): SwitchStateTuple => {
const context = React.useContext(SwitchContext);
if (!context) {
throw new Error(`useSwitch must be used within a SwitchProvider.`);
}
return context;
};
const SwitchContextProvider = (props: object) => {
const [isOn, setOn] = React.useState(false);
const [value, setValue] = React.useMemo(() => [isOn, setOn], [isOn]);
return (<SwitchContext.Provider value={[value, setValue]} {...props} />);
};
export { SwitchContextProvider, useSwitchContext };
Then, in the main file, after importing the SwitchContextProvider and useSwitchContext hook, wrap the app's content in the context provider:
const App = () => {
return (
<SwitchContextProvider>
<NavigationContainer>
{MainStackScreen()}
</NavigationContainer>
</SwitchContextProvider>
);
};
Use the custom hook in the Home screen:
const HomeScreen = () => {
const [isOn, setOn] = useSwitchContext();
return (
<SafeAreaView>
<Switch
style={styles.switch}
ios_backgroundColor="#3e3e3e"
onValueChange={setOn}
value={isOn}
/>
</SafeAreaView>
);
};
And in the Login button component:
const LoginButton = (): JSX.Element => {
const navigation = useNavigation();
const [isOn] = useSwitchContext();
const handleClick = () => {
navigation.navigate('Away');
};
return (
<Button title="Login"
color="white"
disabled={!isOn}
onPress={handleClick} />
);
};
I created the above by adapting an example I found here:
https://kentcdodds.com/blog/application-state-management-with-react
The whole project is now up on GitHub, as a reference:
https://github.com/software-mariodiana/hellonavigate
If you want to choose the context method, you need to create a component first that creates our context:
import React, { createContext, useReducer, Dispatch } from 'react';
type ActionType = {type: 'TOGGLE_STATE'};
// Your initial switch state
const initialState = false;
// We are creating a reducer to handle our actions
const SwitchStateReducer = (state = initialState, action: ActionType) => {
switch(action.type){
// In this case we only have one action to toggle state, but you can add more
case 'TOGGLE_STATE':
return !state;
// Return the current state if the action type is not correct
default:
return state;
}
}
// We are creating a context using React's Context API
// This should be exported because we are going to import this context in order to access the state
export const SwitchStateContext = createContext<[boolean, Dispatch<ActionType>]>(null as any);
// And now we are creating a Provider component to pass our reducer to the context
const SwitchStateProvider: React.FC = ({children}) => {
// We are initializing our reducer with useReducer hook
const reducer = useReducer(SwitchStateReducer, initialState);
return (
<SwitchStateContext.Provider value={reducer}>
{children}
</SwitchStateContext.Provider>
)
}
export default SwitchStateProvider;
Then you need to wrap your header, your home screen and all other components/pages in this component. Basically you need to wrap your whole app content with this component.
<SwitchStateProvider>
<AppContent />
</SwitchStateProvider>
Then you need to use this context in your home screen component:
const HomeScreen = () => {
// useContext returns an array with two elements if used with useReducer.
// These elements are: first element is your current state, second element is a function to dispatch actions
const [switchState, dispatchSwitch] = useContext(SwitchStateContext);
const toggleSwitch = () => {
// Here, TOGGLE_STATE is the action name we have set in our reducer
dispatchSwitch({type: 'TOGGLE_STATE'})
}
return (
<SafeAreaView>
<Switch
style={styles.switch}
ios_backgroundColor="#3e3e3e"
onValueChange={toggleSwitch}
value={switchState}
/>
</SafeAreaView>
);
};
And finally you need to use this context in your button component:
// We are going to use only the state, so i'm not including the dispatch action here.
const [switchState] = useContext(SwitchStateContext);
<Button title="Login"
color="white"
disabled={!switchState}
onPress={handleClick} />
Crete a reducer.js :
import {CLEAR_VALUE_ACTION, SET_VALUE_ACTION} from '../action'
const initialAppState = {
value: '',
};
export const reducer = (state = initialAppState, action) => {
if (action.type === SET_VALUE_ACTION) {
state.value = action.data
}else if(action.type===CLEAR_VALUE_ACTION){
state.value = ''
}
return {...state};
};
Then action.js:
export const SET_VALUE_ACTION = 'SET_VALUE_ACTION';
export const CLEAR_VALUE_ACTION = 'CLEAR_VALUE_ACTION';
export function setValueAction(data) {
return {type: SET_VALUE_ACTION, data};
}
export function clearValueAction() {
return {type: CLEAR_VALUE_ACTION}
}
In your components :
...
import {connect} from 'react-redux';
...
function ComponentA({cartItems, dispatch}) {
}
const mapStateToProps = (state) => {
return {
value: state.someState,
};
};
export default connect(mapStateToProps)(ComponentA);
You can create more components and communicate between them, independently.
Perhaps what I think can solve my issue is not the right one. Happy to hearing ideas. I am getting:
Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and async task in a useEffect cleanup function
and tracked it down to one component that is in my headerRight portion of the status bar. I was under the impression it mounts only once. Regardless, the component talks to a syncing process that happens and updates the state. For each status of the sycing, a different icon is displayed.
dataOperations is a NativeModules class that talks to some JAVA that does the background syncing and sends the status to RN.
import React, {useState, useEffect} from 'react';
import {DeviceEventEmitter } from 'react-native';
import DataOperations from "../../../../lib/databaseOperations"
const CommStatus: () => React$Node = () => {
let [status, updateStatus] = useState('');
const db = new DataOperations();
const onCommStatus = (event) => {
status = event['status'];
updateStatus(status);
};
const startSyncing = () => {
db.startSyncing();
};
const listner = DeviceEventEmitter.addListener(
'syncStatusChanged',
onCommStatus,
);
//NOT SURE THIS AS AN EFFECT
const removeListner = () =>{
DeviceEventEmitter.removeListener(listner)
}
//REMOVING THIS useEffect hides the error
useEffect(() => {
startSyncing();
return ()=>removeListner(); // just added this to try
}, []);
//TODO: find icons for stopped and idle. And perhaps animate BUSY?
const renderIcon = (status) => {
//STOPPED and IDLE are same here.
if (status == 'BUSY') {
return (
<Icon
name="trending-down"
/>
);
} else if (status == 'IS_CONNECTING') {
...another icon
}
};
renderIcon();
return <>{renderIcon(status)}</>;
};
export default CommStatus;
The component is loaded as part of the stack navigation as follows:
headerRight: () => (
<>
<CommStatus/>
</>
),
you can use App.js for that.
<Provider store={store}>
<ParentView>
<View style={{ flex: 1 }}>
<AppNavigator />
<AppToast />
</View>
</ParentView>
</Provider>
so in this case will mount only once.
I want to pass navigation props to a firebase notificationListener in App.js but this.props.navigation is undefined which I can understand as App.js is the root where navigation is initiated.
If there is any workaround it would be great.
Thanks!
class App extends Component {
componentDidMount() {
notificationListener.initNotificationListener(this.props.navigation);
}
render() {
return (
<Provider store={store}>
<PersistGate persistor={persistor} loading={null}>
<Navigation />
</PersistGate>
</Provider>
);
}
}
export default App
One way you can workaround not having access to props.navigation in app.js when opening a notification is by setting up a value in your async storage when the app has been opened from a notification
//IN APP.JS
const notificationOpen = await
firebase.notifications().getInitialNotification();
if (notificationOpen) {
this._accessFromNotification();
}
_accessFromNotification = async () => {
console.log("Setting Access from Notification")
await AsyncStorage.setItem('accessFromNot', true);}
After that you can call this variable from your async storage inside the componentDidMount of the first component from your navigation Stack and from there navigate to another component if the variable's value==true.
//IN THE FIRST COMPONENT THAT HAS ACCESS TO PROPS NAVIGATION
componentDidMount() {
this._verifyOpenFromNot()
}
_verifyOpenFromNot = async()=>{
const acc= await AsyncStorage.getItem('accessFromNot');
if (acc){
this.props.navigation.navigate('NotificationViewer');
this._setAccessFalse();
}
}
Finally you should update the async storage setting up the accessFromNot variable to false, to avoid automatic navigation the next time you open the app.
_setEntroDesdeNotFalse = async () => {
await AsyncStorage.setItem('accessFromNot', 'false');}
I have a couple of buttons that acts as routes. Everytime the route is changed, I want to make sure the button that is active changes.
Is there a way to listen to route changes in react router v4?
I use withRouter to get the location prop. When the component is updated because of a new route, I check if the value changed:
#withRouter
class App extends React.Component {
static propTypes = {
location: React.PropTypes.object.isRequired
}
// ...
componentDidUpdate(prevProps) {
if (this.props.location !== prevProps.location) {
this.onRouteChanged();
}
}
onRouteChanged() {
console.log("ROUTE CHANGED");
}
// ...
render(){
return <Switch>
<Route path="/" exact component={HomePage} />
<Route path="/checkout" component={CheckoutPage} />
<Route path="/success" component={SuccessPage} />
// ...
<Route component={NotFound} />
</Switch>
}
}
To expand on the above, you will need to get at the history object. If you are using BrowserRouter, you can import withRouter and wrap your component with a higher-order component (HoC) in order to have access via props to the history object's properties and functions.
import { withRouter } from 'react-router-dom';
const myComponent = ({ history }) => {
history.listen((location, action) => {
// location is an object like window.location
console.log(action, location.pathname, location.state)
});
return <div>...</div>;
};
export default withRouter(myComponent);
The only thing to be aware of is that withRouter and most other ways to access the history seem to pollute the props as they de-structure the object into it.
As others have said, this has been superseded by the hooks exposed by react router and it has a memory leak. If you are registering listeners in a functional component you should be doing so via useEffect and unregistering them in the return of that function.
v5.1 introduces the useful hook useLocation
https://reacttraining.com/blog/react-router-v5-1/#uselocation
import { Switch, useLocation } from 'react-router-dom'
function usePageViews() {
let location = useLocation()
useEffect(
() => {
ga.send(['pageview', location.pathname])
},
[location]
)
}
function App() {
usePageViews()
return <Switch>{/* your routes here */}</Switch>
}
You should to use history v4 lib.
Example from there
history.listen((location, action) => {
console.log(`The current URL is ${location.pathname}${location.search}${location.hash}`)
console.log(`The last navigation action was ${action}`)
})
withRouter, history.listen, and useEffect (React Hooks) works quite nicely together:
import React, { useEffect } from 'react'
import { withRouter } from 'react-router-dom'
const Component = ({ history }) => {
useEffect(() => history.listen(() => {
// do something on route change
// for my example, close a drawer
}), [])
//...
}
export default withRouter(Component)
The listener callback will fire any time a route is changed, and the return for history.listen is a shutdown handler that plays nicely with useEffect.
import React, { useEffect } from 'react';
import { useLocation } from 'react-router';
function MyApp() {
const location = useLocation();
useEffect(() => {
console.log('route has been changed');
...your code
},[location.pathname]);
}
with hooks
With hooks:
import { useEffect } from 'react'
import { withRouter } from 'react-router-dom'
import { history as historyShape } from 'react-router-prop-types'
const DebugHistory = ({ history }) => {
useEffect(() => {
console.log('> Router', history.action, history.location)
}, [history.location.key])
return null
}
DebugHistory.propTypes = { history: historyShape }
export default withRouter(DebugHistory)
Import and render as <DebugHistory> component
import { useHistory } from 'react-router-dom';
const Scroll = () => {
const history = useHistory();
useEffect(() => {
window.scrollTo(0, 0);
}, [history.location.pathname]);
return null;
}
With react Hooks, I am using useEffect
import React from 'react'
const history = useHistory()
const queryString = require('query-string')
const parsed = queryString.parse(location.search)
const [search, setSearch] = useState(parsed.search ? parsed.search : '')
useEffect(() => {
const parsedSearch = parsed.search ? parsed.search : ''
if (parsedSearch !== search) {
// do some action! The route Changed!
}
}, [location.search])
in this example, Im scrolling up when the route change:
import React from 'react'
import { useLocation } from 'react-router-dom'
const ScrollToTop = () => {
const location = useLocation()
React.useEffect(() => {
window.scrollTo(0, 0)
}, [location.key])
return null
}
export default ScrollToTop
In some cases you might use render attribute instead of component, in this way:
class App extends React.Component {
constructor (props) {
super(props);
}
onRouteChange (pageId) {
console.log(pageId);
}
render () {
return <Switch>
<Route path="/" exact render={(props) => {
this.onRouteChange('home');
return <HomePage {...props} />;
}} />
<Route path="/checkout" exact render={(props) => {
this.onRouteChange('checkout');
return <CheckoutPage {...props} />;
}} />
</Switch>
}
}
Notice that if you change state in onRouteChange method, this could cause 'Maximum update depth exceeded' error.
For functional components try useEffect with props.location.
import React, {useEffect} from 'react';
const SampleComponent = (props) => {
useEffect(() => {
console.log(props.location);
}, [props.location]);
}
export default SampleComponent;
For React Router v6 & React Hooks,
You need to use useLocation instead of useHistory as it is deprecated
import { useLocation } from 'react-router-dom'
import { useEffect } from 'react'
export default function Component() {
const history = useLocation();
useEffect(() => {
console.log('> Router', history.pathname)
}, [history.pathname]);
}
With the useEffect hook it's possible to detect route changes without adding a listener.
import React, { useEffect } from 'react';
import { Switch, Route, withRouter } from 'react-router-dom';
import Main from './Main';
import Blog from './Blog';
const App = ({history}) => {
useEffect( () => {
// When route changes, history.location.pathname changes as well
// And the code will execute after this line
}, [history.location.pathname]);
return (<Switch>
<Route exact path = '/' component = {Main}/>
<Route exact path = '/blog' component = {Blog}/>
</Switch>);
}
export default withRouter(App);
I just dealt with this problem, so I'll add my solution as a supplement on other answers given.
The problem here is that useEffect doesn't really work as you would want it to, since the call only gets triggered after the first render so there is an unwanted delay.
If you use some state manager like redux, chances are that you will get a flicker on the screen because of lingering state in the store.
What you really want is to use useLayoutEffect since this gets triggered immediately.
So I wrote a small utility function that I put in the same directory as my router:
export const callApis = (fn, path) => {
useLayoutEffect(() => {
fn();
}, [path]);
};
Which I call from within the component HOC like this:
callApis(() => getTopicById({topicId}), path);
path is the prop that gets passed in the match object when using withRouter.
I'm not really in favour of listening / unlistening manually on history.
That's just imo.