I am fetching an array of two objects. there are "title" and "iqtiboslar" array inside objects. and show it in SectionList but it is giving an error: "can not read properties of undefined(reading 'length')". Here is my code. Any ideas will be highly appreciated
const Item = ({iqtiboslar}) => (
<View>
<Text>{iqtiboslar}</Text>
</View>
);
const HomeScreen = ({navigation}) => { const [quote, setQuote] = useState();
useEffect(() => {
fetchQuotes();
return () => {
setQuote();
};
}, []);
const fetchQuotes = async () => {
try {
const quoteCollection = await firestore().collection('iqtiboslar').get(); // get(:field) to get specific doc
quoteCollection._docs.map(doc => setQuote(doc.data().items));
// quoteCollection._docs.map(doc => console.log(doc));
} catch (error) {
console.log(error);
}
};
return (
<View style={styles.container}>
{quote ? (
<SectionList
sections={quote}
keyExtractor={(item, index) => item + index}
renderItem={({item}) => <Item title={item.title} />}
renderSectionHeader={({section}) => <Text>{section.title}</Text>}
/>
) : (
<ActivityIndicator />
)} </View>
);
};
export default HomeScreen;
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
},
text: {
color: 'red',
},
});
Try this code
<SectionList
sections={quote}
keyExtractor={(item, index) => item + index}
renderItem={({item}) => <Text>{item}</Text>}
renderSectionHeader={({section: {title}}) => (
<Text style={styles.text}>{title}</Text>
)}
Related
I am trying to display some fetched products in a FlatList, also to display more products when I reach the end of this FlatList, but I am getting this error: Invariant Violation: ScrollView child layout (["alignItems"]) must be applied through the contentContainerStyle prop.
When I change alignItems from style to contentContainerStyle the app closes without showing an error or alert.
If I remove the alignItems from container the app closes too
export default function NewProducts() {
const [products, setProducts] = useState([]);
const [isLoading, setisLoading] = useState(false);
const [startLimit, setStartLimit] = useState({ start: 0, limit: 10 });
const navigation = useNavigation();
useEffect(() => {
setisLoading(true);
getProducts();
}, [startLimit]);
const gotoProduct = (id) => {
navigation.push("product", { idProduct: id });
};
const getProducts = async () => {
const response = await getLastProductsApi(
startLimit.start,
startLimit.limit
);
console.log(response);
setProducts(response);
};
const renderItem = ({product}) => {
return (
<TouchableWithoutFeedback
key={product.id}
onPress={() => gotoProduct(product.id)}
>
<View style={styles.containerProduct}>
<View style={styles.product}>
<Image
style={styles.image}
source={{
uri: `${product.attributes.images.data[0].attributes.formats.small.url}`,
}}
/>
<Text style={styles.name} numberOfLines={1} ellipsizeMode="tail">
{product.attributes.title}
</Text>
</View>
</View>
</TouchableWithoutFeedback>
);
};
const renderFooter = () => {
return isLoading && <Loading text="Loading more products" size="medium" />;
};
const handleLoadMore = () => {
setStartLimit({
start: startLimit.start + 10,
limit: startLimit.limit + 10,
});
setisLoading(true);
};
return (
<FlatList
style={styles.container}
numColumns={2}
data={products}
renderItem={renderItem}
keyExtractor={(item, index) => index.toString()}
ListFooterComponent={renderFooter}
onEndReached={handleLoadMore}
onEndReachedThreshold={0}
/>
);
}
const styles = StyleSheet.create({
container: {
alignItems: "flex-start",
marginTop: 1,
},
containerProduct: {
padding: 3,
},
product: {
padding: 10,
backgroundColor: "#f0f0f0",
borderRadius: 20,
},
image: {
height: 150,
resizeMode: "contain",
borderRadius: 20,
},
name: {
marginTop: 15,
fontSize: 15,
},
});
Here is where I call this component
export default function Home() {
return (
<>
<StatusBarCustom
backgroundColor={colors.primary}
barStyle="light-content"
/>
<Search />
<View>
<Banner />
<NewProducts />
</View>
</>
);
}
When you use renderItem from FlatList you have to use item and not product: https://reactnative.dev/docs/flatlist#required-renderitem
You can replace
const renderItem = ({product}) => {
By
const renderItem = ({item}) => {
Hello I'm facing with render error in my movie app during printing results for movie searching. Im working in React-Native 0.70.5. Here is some code for this activity
`
import React,{useState,useEffect} from 'react';
import axios from 'axios';
import { View, StyleSheet, Text, TextInput,ScrollView } from "react-native";
const Search = () => {
const apiurl="https://api.themoviedb.org/3/search/movie?api_key=XXX"
const [state,setState] = useState({
s: "Enter a movie",
results:[]
});
const search = () => {
axios(apiurl + "&query="+ state.s).then(({ data }) => {
let results = data.search;
console.log(data);
setState(prevState => {
return{...prevState, results: results }
})
})
}
return (
<View>
<TextInput
onChangeText={text => setState(prevState => {
return {...prevState, s:text}
})}
onSubmitEditing={search}
value={state.s}
/>
<ScrollView>
{state.results.map(result =>(
<View key={result.id}>
<Text>{result.title}</Text>
</View>
))}
</ScrollView>
</View>
);
}
const styles = StyleSheet.create({
center: {
flex: 1,
justifyContent: "center",
alignItems: "center",
textAlign: "center",
},
});
export default Search;
`
How to change the construction of this function to print movie titles corectly ?
This is just an example and not the best way to do it.
You need a success flag, something like this:
const [success,setSuccess] = useState(false);
const search = () => {
axios(apiurl + "&query="+ state.s).then(({ data }) => {
let results = data.results;
console.log(data);
setState(prevState => {
return{...prevState, results: results }
})
setSuccess(true);
})
}
<ScrollView>
{success && state.results.map(result =>(
<View key={result.id}>
<Text>{result.title}</Text>
</View>
))}
</ScrollView>
I am not sure but you can try this below ScrollView code...
<ScrollView>
{state.results.length>0 && (state.results.map((result) =>(
<View key={result.id}>
<Text>{result.title}</Text>
</View>
)))}
</ScrollView>
use optional chaining. Might be sometimes you don't get result.
<ScrollView>
{state?.results?.map(result =>(
<View key={result?.id}>
<Text>{result?.title}</Text>
</View>
))}
</ScrollView>
Let me know is it helpful or not
I have two components the first where user can add a place to the favorites and the second is favorites component where user may see all his favorite places. When the user for the first time opens the favorites component everything works as expected: all the favorite places that user has already added to the favorites rendered. But if user go to the first component and add one more place and then go to the second component new place will not appear because component has already rendered and the state didn't changed because useEffect not triggered. Help me please what should I use in my FavouritePlaces component instead of useEffect to rerender this component every time when user open FavouritePlaces?
Component where user can add to favorites:
const ModalWindow = ({navigateToPlace, sendDataToParent, visible, marker}: HomeNavigationProps<"ModalWindow">) => {
const regex = /(<([^>]+)>)|( )|(&nbps)/ig;
const result = marker.description.replace(regex, '');
const [favKeys, setFavKeys] = useState([]);
const onDismiss = () => {
sendDataToParent(false)
}
const onNavigationTap = () => {
onDismiss();
navigateToPlace(true, marker.coordinates);
}
const getFavourites = async () => {
let keys = []
keys = await AsyncStorage.getAllKeys()
setFavKeys(keys);
}
const onHeartPress = async () => {
const jsonValue = JSON.stringify(marker)
try {
if (favKeys.includes(marker.id.toString())){
await AsyncStorage.removeItem(marker.id.toString())
await getFavourites();
} else {
await AsyncStorage.setItem(marker.id.toString(), jsonValue)
await getFavourites();
}
} catch (e) {
console.log('error in onHeartPress', e)
}
console.log('Done.')
//remove after test
try {
await AsyncStorage.removeItem('__react_native_storage_test')
} catch(e) {
// remove error
}
console.log('Done.')
}
return (
<Modal visible={visible} onDismiss={onDismiss} contentContainerStyle={styles.container}>
<IconButton
style={
styles.iconButton
}
icon="close"
color={Colors.black}
size={30}
onPress={() => onDismiss()}
/>
<Text
style={{fontStyle: "italic", fontSize: 20, alignSelf: "center", maxWidth: '75%'}}>{marker.title}
</Text>
<CustomCarousel {...{marker}} />
<ScrollView showsVerticalScrollIndicator={false} style={{marginTop: '3%', marginLeft: '3%', marginRight: '3%'}}>
<Text>{result}</Text>
</ScrollView>
<View style={{flexDirection: "row", justifyContent: "space-around", marginLeft: "3%", marginRight: "3%", marginBottom: "15%"}}>
<TouchableOpacity onPress={() => onNavigationTap()}>
<View style={{flexDirection: "row", alignItems: "center"}}>
<Ionicons size={height/20} name={'navigate-circle-outline'} />
</View>
</TouchableOpacity>
<TouchableOpacity onPress={() => onHeartPress()}>
{marker.id ?
<View style={{flexDirection: "row", alignItems: "center"}}>
{favKeys.includes(marker.id.toString()) ? <Ionicons size={height/20} name={'heart-dislike'} /> : <Ionicons size={height/20} name={'heart'} />}
</View> : undefined}
</TouchableOpacity>
</View>
</Modal>
);
}
export default ModalWindow;
My Favorite Places component:
const FavouritePlaces = ({navigation}: HomeNavigationProps<"FavouritePlaces">) => {
const [markers, setMarkers] = useState([]);
useEffect(() => {
const getFavourites = async () => {
let keys = []
try {
keys = await AsyncStorage.getAllKeys()
} catch (e) {
// read key error
}
let values
try {
let forDeletion = ['__react_native_storage_test', 'NAVIGATION_STATE_KEY-40.0.0'];
keys = keys.filter(item => !forDeletion.includes(item))
values = await AsyncStorage.multiGet(keys)
setMarkers(values)
} catch (e) {
// read error
}
}
getFavourites();
}, [])
const transition = (
<Transition.Together>
<Transition.Out type='fade'/>
<Transition.In type='fade'/>
</Transition.Together>
);
const list = useRef<TransitioningView>(null);
const theme = useTheme()
const width = (wWidth - theme.spacing.m * 3) / 2;
const [footerHeight, setFooterHeight] = useState(0);
return (
<Box flex={1} backgroundColor="background">
<StatusBar style="black" />
<Header
title="Избранные места"
left={{icon: 'menu', onPress: () => navigation.openDrawer()}}
right={{icon: 'shopping-bag', onPress: () => true}}
/>
<Box flex={1}>
<ScrollView showsVerticalScrollIndicator={false} contentContainerStyle={{
paddingBottom: footerHeight,
}}>
<Transitioning.View ref={list} transition={transition} style={{}}>
{markers ?
<Box flexDirection='row' style={{justifyContent: "space-around"}}>
<Box>
{markers
.filter((_, i) => i % 2 === 0).map((currentMarker) => <Picture
key={currentMarker}
place={currentMarker}
width={width}
height={height}
/>)}
</Box>
<Box>
{markers
.filter((_, i) => i % 2 !== 0).map((currentMarker) => <Picture
key={currentMarker}
place={currentMarker}
width={width}
height={height}/>)}
</Box>
</Box> : undefined}
</Transitioning.View>
</ScrollView>
{/*<TopCurve footerHeight={footerHeight}/>*/}
<Box position='absolute' bottom={0} left={0} right={0} onLayout={({
nativeEvent: {
layout: {height},
}
}) => setFooterHeight(height)}>
</Box>
</Box>
</Box>
)
}
export default FavouritePlaces
Try this
useEffect(() => {
// ... Your code goes here
}, [navigation]);
this will render whenever update in navigate
I've found the solution. React navigation has hook useIsFocused, so what can we do is:
import { useIsFocused } from "#react-navigation/native";
const isFocused = useIsFocused();
useEffect(() => {
// ... Your code goes here
}, [isFocused]);
You can use React Context API to share the state across the screens.
Check out this Expo Snack I created.
import {
CompositeNavigationProp,
NavigationContainer,
NavigatorScreenParams,
} from '#react-navigation/native';
import {
createStackNavigator,
StackNavigationProp,
} from '#react-navigation/stack';
import * as React from 'react';
import {
Button,
FlatList,
ListRenderItem,
Text,
TextInput,
View,
} from 'react-native';
type MainStackParamsList = {
FavoritePlacesScreen: undefined;
};
type ModalStackParamsList = {
MainStack: NavigatorScreenParams<MainStackParamsList>;
AddFavoritePlacesModal: undefined;
};
type FavoritePlace = {
id: number;
name: string;
};
type FavoritePlacesContextValue = {
favoritePlaces: FavoritePlace[];
addNewFavoritePlace: (favoritePlace: FavoritePlace) => void;
removeFavoritePlace: (id: number) => void;
};
const FavoritePlacesContext = React.createContext<FavoritePlacesContextValue>({
favoritePlaces: [],
addNewFavoritePlace: () => {},
removeFavoritePlace: () => {},
});
const MainStack = createStackNavigator<MainStackParamsList>();
type FavoritePlacesScreenProps = {
navigation: CompositeNavigationProp<
StackNavigationProp<MainStackParamsList, 'FavoritePlacesScreen'>,
StackNavigationProp<ModalStackParamsList>
>;
};
const FavoritePlacesScreen = ({navigation}: FavoritePlacesScreenProps) => {
const {favoritePlaces, removeFavoritePlace} = React.useContext(
FavoritePlacesContext,
);
const renderItem = React.useCallback<ListRenderItem<FavoritePlace>>(
({item}) => {
return (
<View style={{height: 50, padding: 10, flexDirection: 'row'}}>
<Text style={{fontSize: 16}}>{item.name}</Text>
<Button onPress={() => removeFavoritePlace(item.id)} title="Remove" />
</View>
);
},
[removeFavoritePlace],
);
return (
<View style={{flex: 1}}>
<FlatList
data={favoritePlaces}
keyExtractor={(item) => String(item.id)}
renderItem={renderItem}
/>
<Button
onPress={() => {
navigation.navigate('AddFavoritePlacesModal');
}}
title="Add new favorite"
/>
</View>
);
};
const MainStackNavigator = () => {
return (
<MainStack.Navigator>
<MainStack.Screen
component={FavoritePlacesScreen}
name="FavoritePlacesScreen"
/>
</MainStack.Navigator>
);
};
type AddFavoritePlacesModalProps = {
navigation: StackNavigationProp<
ModalStackParamsList,
'AddFavoritePlacesModal'
>;
};
const AddFavoritePlacesModal = ({navigation}: AddFavoritePlacesModalProps) => {
const {addNewFavoritePlace} = React.useContext(FavoritePlacesContext);
const [favoritePlaceName, setFavoritePlaceName] = React.useState('');
const handleOnSave = React.useCallback(() => {
addNewFavoritePlace({
id: Date.now(),
name: favoritePlaceName,
});
navigation.goBack();
}, [addNewFavoritePlace, favoritePlaceName, navigation]);
return (
<View style={{flex: 1, justifyContent: 'center', alignItems: 'center'}}>
<View style={{borderRadius: 6, borderWidth: 1, borderColor: '#333'}}>
<TextInput
onChangeText={setFavoritePlaceName}
placeholder="Name your favorite place"
/>
</View>
<Button onPress={handleOnSave} title="Save" />
</View>
);
};
// Put the favorite places list screen and the add favorite place modal here.
// Then use FavoritePlacesContext.Provider to wrap ModalStack.Navigator in order
// for the context to be available on MainStack
const ModalStack = createStackNavigator<ModalStackParamsList>();
const ModalNavigator = () => {
const [favoritePlaces, setFavoritePlaces] = React.useState<FavoritePlace[]>(
[],
);
const addNewFavoritePlace = React.useCallback(
(favoritePlace: FavoritePlace) => {
setFavoritePlaces((prev) => [...prev, favoritePlace]);
},
[],
);
const removeFavoritePlace = React.useCallback((id: number) => {
setFavoritePlaces((prev) =>
prev.filter((favoritePlace) => favoritePlace.id !== id),
);
}, []);
return (
<FavoritePlacesContext.Provider
value={{
favoritePlaces,
addNewFavoritePlace,
removeFavoritePlace,
}}
>
<ModalStack.Navigator headerMode="none">
<ModalStack.Screen component={MainStackNavigator} name="MainStack" />
<ModalStack.Screen
component={AddFavoritePlacesModal}
name="AddFavoritePlacesModal"
options={{headerShown: false}}
/>
</ModalStack.Navigator>
</FavoritePlacesContext.Provider>
);
};
const App = () => {
return (
<NavigationContainer>
<ModalNavigator />
</NavigationContainer>
);
};
export default App;
I'm just trying to render my Flalist with my state (ListOfProducts), which is an array of arrays of FirestoreDocumentSnapshot that looks like this:
But nothing is rendering. That's my code:
return (
<View>
<TouchableOpacity onPress={() => console.log(listOfProducts)}>
<Text>Log ListOfProducts</Text>
</TouchableOpacity>
<View style={{flex: 1}}>
<FlatList
style={{flex: 1, width: 200, height: 200}}
data={listOfProducts}
keyExtractor={(item, index) => {
item[index].id;
}}
renderItem={({item}) => (
<View style={{flex: 1}}>
<Text style={{height: 100, width: 100, backgroundColor: 'red'}}>
MON CHIBROS
</Text>
</View>
)}
/>
</View>
</View>
);
Getting my data from Firestore like this:
useEffect(() => {
const unsubscribe = getUserLocation()
.then((location) => getProducts(location.coords))
.catch((e) => {
throw new Error(e.message);
});
const getProducts = async (coords) => {
console.log('getProducts');
let nearbyGeocollections = await geocollection
.limit(10)
.near({
center: new firestore.GeoPoint(coords.latitude, coords.longitude),
radius: 50,
})
.get();
let nearbyUsers = [];
await nearbyGeocollections.forEach((geo) => {
if (geo.id !== user.uid) {
firestore()
.collection('PRODUCTS')
.doc(geo.id)
.collection('USER_PRODUCTS')
.onSnapshot((product) => {
nearbyUsers.push(product.docs);
});
}
});
setLoading(false);
setListOfProducts(nearbyUsers);
};
return () => {
unsubscribe;
setListOfProducts([]);
};
}, []);
If someone can point me out what are my mistakes, I would greatly appreciate.
you are not using the proper way to get data. Try this way
firestore()
.collection('PRODUCTS')
.doc(geo.id)
.collection('USER_PRODUCTS')
.onSnapshot((onResult, onError));
function onResult(QuerySnapshot) {
var nearbyUsers = [];
QuerySnapshot.forEach(function (doc) {
nearbyUsers.push(doc.data());
});
}
function onError(error) {
console.error(error);
}
in query snapshot there may be multiple docs then when you execute doc.data() on each of the doc to get the data from them
I had to rebuild an array of objects to make it works.
unsubscribe = await nearbyGeocollections.forEach((geo) => {
if (geo.id !== user.uid) {
firestore()
.collection("PRODUCTS")
.doc(geo.id)
.collection("USER_PRODUCTS")
.onSnapshot((product) => {
nearbyUsers.push({
id: product.docs[0].id.toString(),
products: product.docs,
});
});
}
});
My Flatlist:
return (
<>
<Animated.FlatList
pagingEnabled={true}
legacyImplementation={false}
data={listOfProducts}
onScroll={onScroll}
contentContainerStyle={{ paddingTop: containerPaddingTop }}
scrollIndicatorInsets={{ top: scrollIndicatorInsetTop }}
initialNumToRender={5}
renderItem={(products) => (
<UserProductsList
user={user}
products={products}
navigation={navigation}
/>
)}
keyExtractor={(item) => item.id}
/>
</>
);
I'm a newbie in React Native and trying to pass props to ListHeaderComponent in FlatList
Here's the code:
const FirstRoute = (props) => {
const _renderHeader = () => {
return(
<View>
{props.isFollowed &&
<TouchableOpacity onPress={props.onSubmit}>
<Text>You have followed this person</Text>
</TouchableOpacity> }
</View>
)
}
return(
<View style={[styles.scene, { backgroundColor: '#ff4081' }]}>
<FlatList
data={data}
keyExtractor={item => item.id}
renderItem={itemData => ( <Image source={itemData.item.id} style={{height: WIDTH/3, width: WIDTH/3}} />)}
ListHeaderComponent={_renderHeader}
/>
</View>
)
};
const SecondRoute = () => (
<View style={[styles.scene, { backgroundColor: '#673ab7' }]} />
);
const initialLayout = { width: Dimensions.get('window').width };
export default function Parent() {
const [index, setIndex] = React.useState(0);
const [routes] = useState([
{ key: 'first', title: 'First' },
{ key: 'second', title: 'Second' },
]);
const [_isFollowed, setIsFollowed] = useState(false);
const _onSubmit = () => {
...
setIsfollowed(true)
}
const renderScene = ({route}) => {
switch(route.key){
case 'first': return <FirstRoute {...props} onSubmit={_onSubmit} isFollowed={_isFollowed} />
case 'second': return <SecondRoute {...props} />
}
};
return (
<TabView
navigationState={{ index, routes }}
renderScene={renderScene}
onIndexChange={setIndex}
initialLayout={initialLayout}
/>
);
}
But when I save it, the screen logs the error: Can't find the value of isFollowed
I think the problem is at the way I pass the props. I'm still learning it. Since when I delete the ListHeaderComponent, the FlatList still generates the list of images well. And I don't know if it has something to do with renderScene
I really don't understand why
Please help me. Thank you very much
Let me get this straight. You need to render _renderHeader dinamically based on _isFollowed state. So, you passed to the first route as props your _onSubmit function and _isFollowed state in order to get to access them at _renderHeader. Right?
As I see you actually doesn't need to do it once your _renderHeader has direct access to both _isFollowed state and _onSubmit function. Try it out as bellow:
export default function Parent() {
const [index, setIndex] = React.useState(0);
const [routes] = useState([
{ key: 'first', title: 'First' },
{ key: 'second', title: 'Second' },
]);
const [_isFollowed, setIsFollowed] = useState(false);
const initialLayout = { width: Dimensions.get('window').width };
function _onSubmit() {
setIsFollowed(true);
}
function _renderHeader() {
return (
<View>
{_isFollowed &&
<TouchableOpacity onPress={_onSubmit}>
<Text>You have followed this person</Text>
</TouchableOpacity> }
</View>
);
}
const FirstRoute = () => {
return(
<View style={[styles.scene, { backgroundColor: '#ff4081' }]}>
<FlatList
data={data}
keyExtractor={item => item.id}
renderItem={itemData => ( <Image source={itemData.item.id} style={{height: WIDTH/3, width: WIDTH/3}} />)}
ListHeaderComponent={_renderHeader}
/>
</View>
)
};
const SecondRoute = () => (
<View style={[styles.scene, { backgroundColor: '#673ab7' }]} />
);
const renderScene = ({route}) => {
switch(route.key){
case 'first': return <FirstRoute />
case 'second': return <SecondRoute />
}
};
return (
<TabView
navigationState={{ index, routes }}
renderScene={renderScene}
onIndexChange={setIndex}
initialLayout={initialLayout}
/>
);
}
Other point I don't understand in your code and couldn't check cause I didn't try to run it was the function bellow:
function _renderHeader() {
return (
<View>
{_isFollowed &&
<TouchableOpacity onPress={_onSubmit}>
<Text>You have followed this person</Text>
</TouchableOpacity> }
</View>
);
}
If you want to render TouchableOpacity just in case _isFollowed is true you should do it using ternary operator like so:
function _renderHeader() {
return (
<View>
{_isFollowed ?
<TouchableOpacity onPress={_onSubmit}>
<Text>You have followed this person</Text>
</TouchableOpacity> }
: <></>
}
</View>
);
}