I've thoroughly read the documentation on passing params between screens with React Navigation: https://reactnavigation.org/docs/params/
However, all of those examples only work if you are calling navigation.navigate manually and passing the params. For example:
<Button
title="Done"
onPress={() => {
// Pass and merge params back to home screen
navigation.navigate({
name: 'Home',
params: { post: postText },
merge: true,
});
}}
/>
I have a screen with a back button, where I can call navigation.navigate and pass params on button press, like in the example above. However, the user can also swipe from the left to go back to the first screen on Android (and I'm assuming iOS as well).
So, my question:
Is there a way for me to pass the same data to the previous screen when the user swipes to go back (instead of pressing the back button)?
There might be a better way that I am unaware of. However, we can achieve this manually by preventing the default back action and handling this ourselves.
Suppose that you have a screen B and you want to swipe back to go to a screen Home and pass params to Home from B on that swipe action. Then, you can achieve this as follows.
function B({navigation}) {
React.useEffect(() => navigation.addListener('beforeRemove', (e) => {
// the navigation.navigate will fire beforeRemove which causes an infinite loop. we guard this here
if (e.data.action.type === "NAVIGATE") {
return
}
// Prevent default behavior of leaving the screen
e.preventDefault();
// navigate manually
navigation.navigate({
name: 'Home',
params: { post: postText },
merge: true,
});
}), [navigation]);
return ( ... )
}
Edit: The navigation.navigate fires the beforeRemove event again, obviously, which causes an infinite loop. We can guard this as shown above.
Related
The context is a simple React Native app with React Navigation.
There are 3 screens.
The first simply displays a button to go to second screen using navigation.navigate("SecondScreen").
The Second contains a hook (see code below) that adds a listener to listen the mouse position. This hook adds the listener in a useEffect hook and removes the listener in the useEffect cleanup function. I just added a console.log in the listener function to see when the function is triggered.
This screen contains also a button to navigate to the Third screen, that only shows a text.
If I go from first screen to second screen: listener in hook start running. Good.
If I go back to the first screen using default react navigation 's back button in header. the listener stops. Good.
If I go again to second screen, then listener runs again. Good.
But if I now go from second screen to third screen, the listener is still running. Not Good.
How can I unmount the hook when going to third screen, and mount it again when going back to second screen?
Please read the following before answering :
I know that:
this is due to the fact that react navigation kills second screen when we go back to first screen, and then trigger the cleanup function returned by the useEffect in the hook. And that it doesn't kill second screen when we navigate to third screen, and then doesn't trigger the cleanup function.
the react navigation's hook useFocusEffect could be used to resolve this kind of problem. But it can't be used here because it will involve to replace the useEffect in the hook by the useFocusEffect. And I want my hook to be usable in every context, even if react navigation is not installed. More, I'm using here a custom hook for explanation, but it's the same problem for any hook (for example, the native useWindowDimensions).
Then does anyone know how I could manage this case to avoid to have the listener running on third screen ?
This is the code of the hook sample, that I take from https://github.com/rehooks/window-mouse-position/blob/master/index.js, but any hook could be used.
"use strict";
let { useState, useEffect } = require("react");
function useWindowMousePosition() {
let [WindowMousePosition, setWindowMousePosition] = useState({
x: null,
y: null
});
function handleMouseMove(e) {
console.log("handleMouseMove");
setWindowMousePosition({
x: e.pageX,
y: e.pageY
});
}
useEffect(() => {
window.addEventListener("mousemove", handleMouseMove);
return () => {
window.removeEventListener("mousemove", handleMouseMove);
};
}, []);
return WindowMousePosition;
}
module.exports = useWindowMousePosition;
the react navigation's hook useFocusEffect could be used to resolve this kind of problem. But it can't be used here because it will involve to replace the useEffect in the hook by the useFocusEffect. And I want my hook to be usable in every context, even if react navigation is not installed
So your hook somehow needs to know about the navigation state. If you can't use useFocusEffect, you'll need to pass the information about whether the screen is focused or not (e.g. with an enabled prop).
function useWindowMousePosition({ enabled = true } = {}) {
let [WindowMousePosition, setWindowMousePosition] = useState({
x: null,
y: null
});
useEffect(() => {
if (!enabled) {
return;
}
function handleMouseMove(e) {
console.log("handleMouseMove");
setWindowMousePosition({
x: e.pageX,
y: e.pageY
});
}
window.addEventListener("mousemove", handleMouseMove);
return () => {
window.removeEventListener("mousemove", handleMouseMove);
};
}, [enabled]);
return WindowMousePosition;
}
And then pass enabled based on screen focus:
const isFocused = useIsFocused();
const windowMousePosition = useWindowMousePosition({ enabled: isFocused });
Note that this approach will need the screen to re-render when it's blurred/focused unlike useFocusEffect.
I'm trying to make a function execute when a view is in foreground, but just once not on each update of the component. If the user navigates to another view and goes back to the first view it should execute that function again, but just once. Is there a solution to this?
if using useEffect without second parameter it executes on each update, if I add [] as second parameter it only executes the first time the view is rendered but not when navigating back to it.
Any help appreciated!
if you are using react-navigation you can do this by listen on screen focus see here
React.useEffect(() => {
const unsubscribe = navigation.addListener('focus', () => {
// The screen is focused
// Call any action
});
// Return the function to unsubscribe from the event so it gets removed on unmount
return unsubscribe;
}, [navigation]);
I am using a switchNavigator to display either a show view or a view where the user can add more content. I want to send back a boolean variable just as a flag, I think I have that part just right but I don't know how to make it so that my code receives it and changes view.
This is in my routes.js
let hasItems = true;
const ItemsScreens = createSwitchNavigator(
{
Items: {
screen: Items,
},
ItemsExist: {
screen: ExistingItems,
},
},
{
mode: 'card',
initialRouteName: hasItems ? 'ItemsExist' : 'Items',
navigationOptions: {
drawerIcon: getDrawerItemIcon('account-balance-wallet'),
title: `Items`,
},
},
);
inside my ExistingItems.js I have a button that does:
<Button
onPress={() => this.props.navigation.navigate('Items', {hasItems: false})}
label={'Add Items'}
/>
My idea is to call the view again but send the false value in the variable to enter the actual adding items state but I have no idea how to make it actually receive the value. I tried doing an if like:
if(this.props.navigation.state.params.hasItems)
but that is undefined and crashes.
As suggested in react navigation Authentication flows example, create one another screen AuthLoadingScreen, which checks the condition and according to condition navigate to your another screen. However, I also know that extra screen will not good for user UI but it will work around.
Which property is seen as undefined?
Aren't you also controlling the wrong variable? the param you are passing is hasBanks but you are controlling hasItems
Perhaps someone can help me with a React Native issue I’m having with react-navigation (2.0.4). I have a page (Page C - RouteShowScreen) that I want to conditionally reload, depending on whether or it was navigated to from Page A (RoutePrepareScreen) or Page X (Any other page navigating to Page C), and I just can’t seem to get the lifecyle methods correct. To be clear, I want the page to reload if it is navigated to from Page A (RoutePrepareScreen), but not if it is navigated to from any other screen. I tried using the willFocus listener, but then Page C reloads regardless of whether it was navigated to from Page A or Page B.
RoutePrepareScreen
...
this.props.navigation.navigate("RouteShow", {
currentLat: latitude,
currentLng: longitude,
destinationAddress: this.state.destinationAddress,
currentAddress: this.formatCurrentAddress(),
destinationLat,
destinationLng,
speed,
hoursUntilBreak,
estimatedShiftLength});
}
...
RouteShowScreen
/** This caused the page to reload, regardless of how it was navigated to **/
willFocus = this.props.navigation.addListener(
'willFocus',
() => {
this.handleRouteLoad();
}
);
/** I also tried using componentWillReceiveProps and adding an additional "reload" navigation parameter, but this threw the
app into an infinite loop **/
componentWillReceiveProps(nextProps) {
if (nextProps.navigation.state.params.reload) {
this.handleRouteLoad();
}
}
In my particular case, I was able to get this to work by resetting the navigation stack when navigating from within RoutePrepareScreen - like this:
const resetAction = StackActions.reset({
index: 0,
actions: [
NavigationActions.navigate({
routeName: "RouteShow",
params: {
currentLat: latitude,
currentLng: longitude,
destinationAddress: this.state.destinationAddress,
currentAddress: this.formatCurrentAddress(),
destinationLat,
destinationLng,
speed,
hoursUntilBreak,
estimatedShiftLength,
}
})
],
});
this.props.navigation.dispatch(resetAction);
However, this feels a little dirty to me (and might be untenable if the use case cannot handle a full reset of the navigation stack). I'd be curious to see another solution!
I am using reactnavigation component from https://reactnavigation.org and using the code below i am going one screen back
<Button
onPress={() => goBack()}
title="Go back from this HomeScreen"
/>
how can i go 2 screen back on single press action
I am using this code to initialize the navigator
const RouteConfigs = {
Login: {screen:Login},
Home: {screen:Home},
Chat: {screen:Chat},
Facebook: {screen:Facebook},
Facebookgallery: {screen:Facebookgallery}
}
const StackNavigatorConfig = {
headerMode: 'none',
}
export default StackNavigator(RouteConfigs, StackNavigatorConfig)
I navigate from home to Facebook with this code :
() => this.props.navigation.navigate('Facebook', {user:this.state.user})
and from Facebook to Facebookgallery with this code :
onPress={ () => this.props.navigation.navigate('Facebookgallery', {user:this.state.user}) }
now i want to go back from Facebookgallery to Home directly with some parameters
I know it's an older question but what I use is:
navigation.pop(n);
Takes you to the previous screen in the stack. If you provide a number, n, it will specify how many screens to take you back within the stack.
https://reactnavigation.org/docs/en/navigation-prop.html
you can use navigation.pop(screenCount)
with screenCount as integer
navigation.pop(2)
here is for refference
https://reactnavigation.org/docs/stack-actions#pop
React Navigation is updated not to use pop function directly, use dispatch function with StackActions.
navigation.dispatch(StackActions.pop(2));
navigation.navigate({ routeName: SCREEN, key: SCREEN_KEY_A });
navigation.navigate({ routeName: SCREEN, key: SCREEN_KEY_B });
navigation.navigate({ routeName: SCREEN, key: SCREEN_KEY_C });
navigation.navigate({ routeName: SCREEN, key: SCREEN_KEY_D });
Now you are on-screen D and want to go back to screen A (popping D, C, and B). Then you need to supply a key to goBack FROM:
navigation.goBack(SCREEN_KEY_B)
https://reactnavigation.org/docs/en/navigation-prop.html#going-back-from-a-specific-screen-with-goback
The "proper" solution right now is:
Get the key for the screen after the screen you want to go to. In
your case, you'll need to get the key for the Facebook screen.
Call NavigationAction.back(key: 'key-of-previous-screen'), and it
will pop your navigation stack as if you were on the screen with that key
Code example where I go back multiple screens in a thunk (relevant if you use redux):
export const postItemAndReturnToMap = item => (dispatch, getState) => {
const {nav} = getState();
// Get the key for the screen after/above the root view and use that as reference
// to return to the root view. This is hardcoded for my stack setup, as you can see
// there are quite a few nested StackNavigators in my setup
const {key} = nav.routes[0].routes[0].routes[0].routes[1];
// Dispatch whatever action you want
dispatch(postItem(item));
// This will now go back multiple screens, in my case to the
// bottom of the top stackNavigator
return dispatch(NavigationActions.back({key}));
};
This isn't pretty. Let's hope react-navigation implements something like .back(2) to make things easier in the future.
If you are using push then you can go to root screen with this
this.props.navigation.popToTop();
and to Push
this.props.navigation.navigate('SummaryScreen', {
otherParam: 'anything you want here',
});
You could define an additional navigation action type, e.g. POP_TWO_ROUTES and overwrite StackRouter.getStateForAction(passedAction, state) like that (only exemplary):
...
const defaultGetStateForAction = AppNavigator.router.getStateForAction;
AppNavigator.router.getStateForAction = (passedAction, state) => {
if(state && state.routes && state.routes.length > 2
&& passedAction.type === 'POP_TWO_ROUTES') {
let routes = state.routes.slice();
routes.pop();
routes.pop();
return {
index: routes.length - 1,
routes: routes
};
}
// default behaviour for none custom types
return defaultGetStateForAction(passedAction, state);
}
...
Then in your screen component you can do something like that:
...
onPress={() => this.props.navigation.dispatch({
type: 'POP_TWO_ROUTES'
})}
...
See also https://reactnavigation.org/docs/routers/#Custom-Navigation-Actions.
It sounds like you're looking for something along the lines of #reset (https://reactnavigation.org/docs/navigators/navigation-actions#Reset).
I haven't used this library, but you likely are trying to go back to the navigation stack's root screen. Other libraries I've used for nav have some sort of popToRoot or something similar.
Try this
onPress={() => {
props.rootNavigation.dispatch(
NavigationActions.reset({
index: 0,
key:null,
actions: [NavigationActions.navigate({ routeName: 'Home' })]
})
)
}}
This should work:
this.props.navigation.pop(2)
For React Native V6 2022
Simple Go Back "goBack"
navigation.goBack()
Go Back tow screen or 3 on specific the name "navigate"
props.navigation.navigate("RouteName")
Navigate to the top screen "popToTop"
navigation.popToTop()