Conditional React Navigation header button - react-native

I am trying to make a button appear in headerRight of the header bar in a React Navigation screen, but I cant seem to get it to work.
I want the start button (what is in headerRight) to show when props.players.length > 1.
Can anyone point me in the right direction?

You can use the same mechanics describe here for title: https://reactnavigation.org/docs/en/headers.html#setting-the-header-title
Set a navigation params and use it on your navigationOptions.
In your case:
state = { players: 0 };
static navigationOptions = ({ navigation }) => {
return {
headerRight: navigation.getParam('players', 0) > 1 ? <YourHeaderButtonComponent /> : null ,
};
};
addPlayer = () => {
this.setState(({players}) => {
this.props.navigation.setParams({players: players + 1})
return {players: players + 1 }
});
}
render {
...
<Button onPress={this.addPlayer}
...
}

If you have a nested navigation for example a child bottomTabNavigator inside a parent stackNavigator please look att applying parent screen options based on child navigator's state see documentation here
For me the second option with Using navigation.setOptions worked with a child bottom tab navigator so I could change stackNavigator header options based on bottomTabNavigator page.

Related

"Undefined" error when passing params to another screen in React Navigation

I have 2 screens, EditProfile and Profile. I'm trying to pass the edited name and date from EditProfile to Profile. They are both stacked in a ProfileNavigator, Profile is the first screen that appears and from there, user can tap on a edit profile button and navigate to Edit Profile Screen. How can i pass updated Edit Screen name and date params to main profile? Following code does not work and return Cannot read property "date" of undefined:
const EditProfileScreen = () => {
const navigation = useNavigation();
}
return (
..
<TouchableOpacity style={styles.commandButton} onPress= {() => {navigation.navigate("Profile", {params: {date: date, name: name }})} }
activeOpacity={0.5}>
<Text style={styles.panelButtonTitle}>Submit</Text>
</TouchableOpacity>
);
While this is the code for the Profile Screen:
const ProfileScreen = ({route, navigation}) => {
const { date } = route.params;
const { name } = route.params;
return (
..
<Text>{JSON.stringify(date)}</Text>
<Text>{JSON.stringify(name)}</Text>
)
There is nothing wrong with your approach, but you are missing null handling for the initial render of the profile screen.
Think like this, the first time you navigate to the profile screen there wont be a route.params as you are not passing any parameters which ends up in an error.
But when you move to the edit screen and come back with parameters you will have the route.params which you can access without any issues.
So change your code like this
<Text>{JSON.stringify(route.params?.date)}</Text>
<Text>{JSON.stringify(route.params?.name)}</Text>
Or if you have the profile object in the state of the profile screen, update it using a useEffect hook based on the change of route.params.

Why Navigation.goBack() not working properly?

I am using following way to create navigation system
StackNavigator -> DrawerNavigator -> (Screen A, Screen B, Screen C)
Screen A is initial Route
Screen A to Screen B Using
this.props.navigation.navigate("Screen B") //Working Fine
Screen B to Screen C Using
this.props.navigation.navigate("Screen C") //Working Fine
In Screen C
this.props.navigation.goBack() //Not Working
But
this.props.navigation.goBack(null) //It's going to Screen A instead of Screen B
What's wrong here.
Please help me Thank you.
As you didn't show the navigation structure of the drawer, I don't know how the 3 screens are put inside of it. I'm assuming they are 3 different drawerScreens
This happens because you are using a DrawerNavigation, that doesn't create a history of screens when you navigate around it.
To solve this you have to change the navigation structure to something like:
DrawerNavigation => StackNavigator => Screen A, B, C
You can specify backBehavior="history" inside Drawer.Navigator and it shouldn't move you to the initial root on goBack anymore :)
Example:
<Drawer.Navigator
backBehavior="history"
>
...
As the answer above is, the drawer navigators are not in the stack, so you can't tell the path of your journey.
the key property for goBack() is a dynamically created string, created by react-navigation whenever navigate to a new route.
These stack keys are stored in this.props.navigation.state
NOTE: Use .goBack(null) if your goal is to return to any place
without specifying a closing target.
Like this example, you can add to the stack.
Example
const Drawers = createDrawerNavigator(
{
A: {
screen: HomeScreen
},
...
},
{
initialRouteName: "A"
}
);
const RootStack = createStackNavigator(
{
Drawers: {
screen: Drawers
},
otherStack: {
screen: otherStack
},
....

Pass variables via `this.props.navigation` multiple times

So, for begging, in react-native-navigation there's a possibility to pass some data via this.props.navigation.navigate().
Here's how you should pass the data :
this.props.navigation.navigate('RouteName', {/*Data to pass*/})
And so, moving to the problem
The case where this problem was encountered :
I have a list of items which I click on and I navigate to the next screen, the data of the pressed item being sent during the navigation process, and when I get to the next screen, the passed data is assigned to state, and I further operate with it. Here are the commands which I use for passing data:
Pass data
this.props.navigation.navigate('Screen2',{param1: value1, param2: value2})
Receive data
ComponentWillMount = () => {
const param1 = this.props.navigation.getParam('param1');
const param2 = this.props.navigation.getParam('param2');
this.setState({param1, param2)}
}
The Problem itself
My Problem is that if I go back to the first screen, and press on another item, then it's data isn't passed via this.props.navigation.navigate(), the data on the second screen remains unmodified from the first navigation process. How this problem can be resolved?
I think i figured it out,
I was able to replicate the issue using drawerNavigator and tabbed navigator in the react-navigation 3.0.5.
Basically they save the components even when you run navigation.goBack.
The screen isn't being mounted again so it doesnt call componentWillMount() and it doesn't check for data there.
there are 2 (edit 3) ways to fix this.
one is to turn off this performance enhancement
const MyApp = createDrawerNavigator(
{
Screen1: Screen1,
Screen2: Screen2
},
{
unmountInactiveRoutes: true
}
);
The second option and the more elegant one is to subscribe to navigation events
componentWillMount() {
console.log("mounting");
const willFocusSubscription = this.props.navigation.addListener(
"willFocus",
() => {
console.debug("willFocus");
const thing = this.props.navigation.getParam("thing");
const thing2 = this.props.navigation.getParam("thing2");
this.setState({thing, thing2});
}
);
}
Just dont forget to unsubscribe in componentWillUnmount
componentWillUnmount() {
willFocusSubscription.remove();
}
The third way is basically the same as the second but subscribing declaratively. This means no componentWillMount or WillUnmount.
First a callback to set the state appropriately
willFocus = ({action}) => {
console.debug("willFocus", action);
const thing = action.params["thing"];
const thing2 = action.params["thing2"];
this.setState({thing, thing2});
};
now in render add the component
render() {
console.log("data is:", this.state.thing);
return (
<View style={styles.container}>
<NavigationEvents
onWillFocus={this.willFocus}
/>
.... rest of render body
</View>
);
}
This doesn't display anything but it takes care of subscribing and unsubscribing.

React Native StackNavigator Title Change Causes Recursion

I've split out the navigationOptions to the top of each screen to make things easy to understand, rather than keeping it in the TabNavigator. Here's an example of one screen:
static navigationOptions = ({navigation}) => {
const {params = {}} = navigation.state;
return {
title: params.title != undefined ? `${params.title}` : "Step 1: Select a Letter",
tabBarOnPress: ({...props, scene})=>{
params.onFocus();
},
titleStyle: {
textAlign: 'center'
}
}
};
Once a user selects a letter on this screen, I switch the view to show a different component (a list of items that start with that letter, for example).
I'd like to change the title of the TabNavigator Header to now show something like "Step 2: Select an item from the list". I saw on a thread that you can call a method from the method that rebuilds the view like this:
_letterSelectedHandler = (letter) => {
this._changeTitle("Step 2: Select an item...");
...
}
With the method:
_changeTitle = (title) => {
this.props.navigation.setParams({title});
}
Unfortunately, it seems to create an infinite loop. Is there a better way of simply changing the TabNavigator Header Title?
I should mention that I'm not using Redux or anything too complex, since I'm new to React Native. Please let me know if I can provide any more information to help illustrate the issue I'm having.

go two screen back with single press event using react-navigation in react native app

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()