ERROR - VirtualizedLists should never be nested inside plain ScrollViews with the same orientation - react-native

I'm working on a react-native app and I have to put a list of object in a Scrollview, so I use the FlatList component to do it. This is the piece of code that generates the error:
<ScrollView contentContainerStyle={style}>
Other components
<FlatList
style={style}
data={data}
scrollEnabled={false}
keyExtractor={(item, index) => index.toString()}
renderItem={({ item, index}) => (somethings)}
/>
Other components
</ScrollView>
The complete error is: VirtualizedLists should never be nested inside plain ScrollViews with the same orientation because it can break windowing and other functionality - use another VirtualizedList-backed container instead.

Avoid using FlatList with the same orientation. Instead, restructure your code like this --
<ScrollView contentContainerStyle={style}>
Other components
{
data.map((item)=> <Somthing item={item}/>)
}
Other components
</ScrollView>

Flatlist has its own ScrollView you can scroll through the list using that so there is no need to put a flatlist into a ScrollView that is why its giving a warning, the both scrollview will clash and one of them (mostly the parent one) works.

The error is self explanatory and it should be in a developers best interest to avoid these kind of things even when it's just a false alarm.
Your particular situation could use the following solution:
<FlatList
data={data}
keyExtractor={(item, index) => `key-${index}`}
ListHeaderComponent={() => (
<SomeComponents>
...Some components those need to be on top of the list
</SomeComponents>
)}
ListFooterComponent={() => (
<SomeComponents>
...Some components those need to be below the list
</SomeComponents>
)}
renderItem={({ item, index}) => (somethings)}
/>
Another note, if you need more complex list that needs header and footer for the list itself, you can try SectionList.

Your component FlatList and ScrollView have the same orientation(vertical), so you need put your component inside a ScrollView with horizontal orientation like this:
<View>
<ScrollView nestedScrollEnabled={true} style={{ width: "100%" }} >
<View>
<ScrollView horizontal={true} style={{ width: "100%" }}>
<FlatList />
</ScrollView>
</View>
</ScrollView>
</View>

Solution 1: Use FlatList props ListHeaderComponent and create all of your page top section in that. Something like this:
This will not show any warning or error.
Solution 2:
Because only parent view will scroll (ScrollView) and not the child FlatList, so to get rid of the warning you can pass a prop scrollEnabled={false} to the FlatList.
If it doesn't go then import LogBox from react-native and write this in your component
useEffect(() => {
LogBox.ignoreLogs(["VirtualizedLists should never be nested"])
}, [])
hopefully, the warning will be removed.

Anyone want to solve this issue can use a custom VirtualizedScrollView like this:
import React from 'react';
import { FlatList } from 'react-native';
const VirtualizedScrollView = props => {
return (
<FlatList
{...props}
data={[]}
keyExtractor={(e, i) => 'dom' + i.toString()}
ListEmptyComponent={null}
renderItem={null}
ListHeaderComponent={() => (
<>{props.children}</>
)}
/>
);
};
export default VirtualizedScrollView;
Then if you use FlatList inside VirtualizedScrollView, it won't get the warning/error.
<VirtualizedScrollView>
<FlatList
/*--- your props ---*/
/>
</VirtualizedScrollView>
There is a npm package where I get this code, you can also use this package

Solution:
I have also encountered same problem with FlatList. Then the package below solved my problem.
'react-native-virtualized-view'
import { ScrollView } from 'react-native-virtualized-view'

if ScrollView is Vertical change Flatlist Horizontal
<ScrollView >
<FlatList
horizontal
data={lenders}
keyExtractor={(_, index) => index}
renderItem={(item) => {
return <Text>item</Text>
}}
/>

You can solve the 2 vertical ones(I'm assuming their side by side, separated with a segemented control?) by using the same flat list and switching out the data when it's switched. If they're just two vertical flat list's one after another use the SectionList.
For the horizontal one you can try putting the Horizontal FlatList in the ListHeaderComponent of the vertical FlatList and see what happens. It can be janky if you use a vertical FlatList in a vertical scroll view but maybe with two different axis it might be ok. The other option is two only show a few items in the horizontal scrollview and have a "Show More".
The last option is too re design/rethink the page so it's not doing so much. On mobile less is more and developers/designers like to get in the mindset of porting desktop thinking onto mobile. Might be worth a shot.

I used the SectionList approach to solve this & wanted to post a code example because I found the Section data required by React Native to be clear but also quite prescriptive.
renderList = ({empty, posts}: {empty: boolean, posts: Array<Object>}) => (
<SectionList
sections={[
{type: 'MAP', data: [{}]}, // Static sections.
{type: 'PROFILE', data: [{}]},
{type: 'POSTS', data: posts} // Dynamic section data replaces the FlatList.
]}
keyExtractor={(item, index) => index}
renderItem={({item, section}) => {
switch (section.type) {
// Different components for each section type.
case 'MAP':
return <MapView />;
case 'PROFILE':
return <Profile />;
case 'POSTS':
return <Post item={item} />;
default:
return null;
}
}}
ItemSeparatorComponent={() => <Separator />}
ListFooterComponent={() => <>{empty && <EmptyList />}</>}
/>
);
What's nice is that the content feels logically quite separate, so you can add sections easily or have different dynamic data sources.
(If you're building a form & want better keyboard handling, you could also try a KeyboardAwareSectionList from react-native-keyboard-aware-scroll-view.)

Flatlist has an integrated scrollview itself, so you can resolve this error by removing ScrollView Component, And let just the Fatlist component

Error ? you are trying to render a FlatList component inside a scrollview component, this is what is throwing the warning.
solution Render the components using Flatlist's ListHeaderComponent={} prop, i.e in your flatlist add the prop as follows
const FlatList_Header = () => {
return (
<View style={{
height: 45,
width: "100%",
backgroundColor: "#00B8D4",
justifyContent: 'center',
alignItems: 'center'
}}
>
<Text style={{ fontSize: 24, color: 'white' }}> Sample FlatList Header </Text>
</View>
);
}
<FlatList
data={BirdsName}
renderItem={({ item }) => <ItemRender name={item.name} />}
keyExtractor={item => item.id}
ItemSeparatorComponent={ItemDivider}
**ListHeaderComponent={FlatList_Header}**
ListHeaderComponentStyle={{ borderBottomColor: 'red', borderBottomWidth: 2 }}
/>
Note the use of the ListHeaderComponent in the code above, that should supress the warning.

Use flatList like this ListHeaderComponent and ListFooterComponent:
<FlatList ListHeaderComponent={
<ScrollView
style={styles.yourstyle}
showsVerticalScrollIndicator={false}
>
<View style={styles.yourstyle}>
</View>
</ScrollView>
}
data={this.state.images}
renderItem={({ item, index }) => {
return (
<View
style={styles.yourstyle}
>
<Image
source={{
uri: item,
}}
style={styles.yourstyle}
resizeMode={"contain"}
/>
<Text
numberOfLines={2}
ellipsizeMode="tail"
style={styles.yourstyle}
>
{item.name}
</Text>
</View>
);
}}
keyExtractor={({ name }, index) => index.toString()}
ListFooterComponent={
<View style={styles.yourstyle}></View>
}
/>

In my case it was happening due to nesting of ScrollView.
Try replacing some of the ScrollView from children components with React.Fragment.

The solution is very simple, please do not put the Flatlist component in the ScrollView.
They both have the same functionality but Flatlist has advantages and is more stable to use.

Related

React Native FlatList performance improvements

I'm reading barcodes and every barcode I read I add to an array and show in flatlist. but after 30 barcodes adding to the array getting slow. is there any solution I can do?
renderItem:
const renderItem = useCallback(
({item, index}) => (
<View style={styles.ListItemContainer}>
<Text>
-{item} index: {index}
</Text>
<TouchableOpacity
onPress={() => {
setRemovedItem(index);
setShowAlert(true);
}}>
<Text style={{fontSize: 20, fontWeight: 'bold'}}>X</Text>
</TouchableOpacity>
</View>
),
[],
);
FlatList component:
<FlatList
renderItem={renderItem}
data={barcodeArray}
style={styles.ListContainer}
keyboardShouldPersistTaps="handled"
initialNumToRender={12}
removeClippedSubviews
windowSize={12}
maxToRenderPerBatch={12}
/>
adding barcode:
const readBarcode = barcode => {
setbarcodeArray([barcode, ...barcodeArray]);
setbarcodeValue('');
setkey(key + 1);
};
for this solution you can use VirtualizedList instead Flatlist . In general, this should only really be used if you need more flexibility than FlatList .
for more info see this
Did you try using this: https://github.com/Flipkart/recyclerlistview library. It renders far fewer items than FlatList and then recycles them. Should be must faster and more performant than the native flatlist. If this does not work then try to use getItemLayout in flatlist if you have a fixed height of the content.

React native List footer component not rendering(funtion component)

I am trying to achieve pagination for infinite scrolling in react native. When loading, I want to render the loading spinner at the bottom of the Flat list component. (Note: I'm using Expo for this app)
const renderFooter = () => {
if (!category.loading) return null;
return (
<View style={spinnerStyles.container}>
<ActivityIndicator animating size="large" color="#0000ff" />
</View>
);
};
return (
<View style={styles.container}>
<FlatList
columnWrapperStyle={{ justifyContent: "space-between" }}
numColumns={2}
data={category.data}
renderItem={categoryItem}
keyExtractor={(item) => item._id + item.sub_category}
onEndReachedThreshold={0}
listFooterComponent={renderFooter}
onEndReached={() => loadMore()}
/>
</View>
);
The loading spinner not correctly working with the flat list footer.
Has anyone run into this issue before, or does anyone have a solution?
Sorry, it's my simple syntax error. It's actually ListFooterComponent not listFooterComponent. Now it's working fine, Thank you.
Instead of calling the refrence, call the function. It should look something like this.
ListFooterComponent={renderFooter()}

VirtualizedLists should never be nested inside plain ScrollViews with the same orientation

I'm building a mobile application with React Native, and I have a ScrollView inside one of the pages.
The problem is that I have in this page a FlatList so when I go to that page, I get this error:
VirtualizedLists should never be nested inside plain ScrollViews with the same orientation... The thing is, I set the ScrollView nestedScrollEnabled to true and I also set the FlatList's scrollEnabled to false because I don't really need the scroll there (I'm using it to render items from an enum) so I thought that should fix the error, but the error still persist.
It looks like this:
<ScrollView showsVerticalScrollIndicator={false} nestedScrollEnabled={true}>
<MyComponent />
</ScrollView>
And MyComponent has this FlatList:
<FlatList
scrollEnabled={false}
style={{padding: 8,marginBottom: 8,}}
data={categories}
numColumns={numOfColumns}
keyExtractor={category => category}
renderItem={item => renderItem(item.item)}
/>
It essentially looks like this:
<SafeAreaView>
<ScrollView>
<FlatList />
<OTHER COMPONENTS />
</ScrollView>
</SafeAreaView>
Your component FlatList and ScrollView have the same orientation(vertical), so you need put your component inside a ScrollView with horizontal orientation like this:
<View>
<ScrollView nestedScrollEnabled={true} style={{ width: "100%" }} >
<View>
<ScrollView horizontal={true} style={{ width: "100%" }}>
<MyComponent />
</ScrollView>
</View>
</ScrollView>
</View>
The error is because you are using a FlatList inside a ScrollView.
The FlatList is already a scrollable component,
FlatList are accepting props like ListHeaderComponent for rendering header content and ListFooterComponent for rendering footer content. Here you can remove the ScrollView and instead of that you can only render FlatList for making whole page scrollable
You need to change your code as shown below:
const _renderHeader = () => <Text>Your Header</Text>
const _renderFooter = () => <Text>Your Footer</Text>
const _renderFooter = () => <Text>FlatList items</Text>
<SafeAreaView>
<FlatList
data={data}
keyExtractor={(item, index) => String(index)}
renderItem={_renderItem}
ListHeaderComponent={_renderHeader}
ListFooterComponent={_renderFooter}
ListFooterComponentStyle={styles.footerStyle} //If you need to give specific styles for footer component
ListHeaderComponentStyle={styles.headerStyle} //for header comp style
/>
</SafeAreaView>
You don't want to use a ScrollView when you are using a FlatList
You can check the official docs for more clarification

How to make Horizontal SectionList RIGHT to LEFT Scroll react-native

I want to make an online shop, I need a Horizontal section List in react native, contains my products. here is my code. please help me to make it right to left scrolling.clothes is an array of objects contains my product's details.
export default class MySectionList extends Component{
render(){
return(
<SectionList
sections={Clothes}
horizontal={true}
showsHorizontalScrollIndicator={false}
renderItem={({item})=>(
<View>
<Image source={{uri:"item.image",width:'65%',height:200}}/>
<Text>{item.name}</Text>
<Text>{item.price}</Text>
</View>
)}
renderSectionHeader={({section})=>(
<Text>{section.title}</Text>)}
/>
)
}
}
this sectionList scrolls from left to right and I need another one scrolling from left to right.
I solve this by adding some styles. Unfortunately, I18NManager could not solve my problem so I used transform style and for all section list I applied transform: [{ scaleX: -1 }] and because of items inside sectionlist will be reversed, I applied this style again for item wrapper. something like this:
render(){
return(
<SectionList
sections={Clothes}
horizontal={true}
style={{ transform: [{ scaleX: -1 }] }}
showsHorizontalScrollIndicator={false}
renderItem={({item})=>(
<View style={{ transform: [{ scaleX: -1 }] }}>
<Image source={{uri:"item.image",width:'65%',height:200}}/>
<Text>{item.name}</Text>
<Text>{item.price}</Text>
</View>
)}
renderSectionHeader={({section})=>(
<Text>{section.title}</Text>)}
/>
)
}
}
This is a hacky way but I did not find another solution for my problem.
I hope this can help you
If your app language is right to left please set app support to use rtl with
I18NManager.allowRTL(true)
I18NManager.forceRTL(true)
to make section list or flat list scroll from right to left, Otherwise this cannot happen. There are another ways to solve this issue but it's not systematic! Like use inverted prop or direction style.
I had a similar demand for the right-to-left functionality. I used horizontal FlatList (in 2022) with an inverted property.
<FlatList
horizontal
data={diaryWeeksAll}
inverted
getItemLayout={(_data, index) => ({ length: width, offset: width * index, index })}
...
See documentation: https://reactnative.dev/docs/flatlist#inverted

React Native FlatList not scrolling to end

I've got (what I thought was) a simple FlatList which renders a list of Cards (code below)
Problem: the list renders, but won't scroll to fully display the last element in the list, OR to the content below the FlatList
What I've tried: basically everything in related SO questions:
Removing ALL styling
Wrapping the FlatList in a View or a ScrollView or both
Adding style={{flex: 1}} to the FlatList or wrappers (this causes **ALL* content to disappear)
Any ideas?
<FlatList
data={props.filteredProducts}
renderItem={({item}) => (
<TouchableOpacity onPress={() => props.addItemToCart(item)}>
<Card
featuredTitle={item.key}
image={require('../assets/icon.png')}
/>
</TouchableOpacity>
)}
keyExtractor={item => item.key}
ListHeaderComponent={
<SearchBar />
}
/>
...
<Other Stuff>
Add style={{flex: 1}} for each View element who is a parent for FlatList.
I had the same issue and just found the solution. Add the prop ListFooterComponentby giving it a React element/component. I just passed a view with the preferable height and it worked for me perfectly.
Here is the code snippet:
<FlatList
data={DATA}
renderItem={({ item }) => (<ListItem itemData={item} />) }
keyExtractor={item => item.id}
ListFooterComponent={<View style={{height: 20}}/>}
/>
This works 100%!
The ultimate solution is ✔
Any view/subview that holds a flatlist must have a flex of 1 - Regardless of how deep.
So if you apply this and it's not working, check your styling and make sure there's no mistake somewhere.
I'm not sure if your scenario is exactly the same as one I encountered on a project a few months ago, but I noticed that I had to add a margin/padding (depends on what you prefer) to lift the bottom of the scrollable container. This was usually because a parent container seemed to interfere with the styling of the scrollable element.
Have you tried adding flexGrow: 1 to your styling in place of flex?
My case is a little different, in that I used FlatList inside bottom sheet provided by reanimated-bottom-sheet package. But the problem was the same: scrolling didn't show the last item properly.
The way I did was I calculated and set the height of the view that included the FlatList. To make it look better when there is bottom inset, I gave more bottom margin to the last item of the FlatList by doing like this:
<FlatList
data={results}
keyExtractor={(item) => item.name}
scrollEnabled={bottomSheetIndex == 1 ? true : false}
renderItem={({ item }) =>
<LocationInfo
bottom={results[results.length - 1].id == item.id ? insets.bottom : 0}
result={item}
wait={waitState[item.id]}
bsIndex={bottomSheetIndex}
/>
}
/>
const LocationInfo = ({ bottom, result, wait, bsIndex }) => {
return (
<View style={[styles.container, { paddingBottom: bottom }]}>
...
for insets, see react-native-safe-area-context.
Remove flex:1 from the FlatList and leave only the parent View.
Add flex: 1 to child into renderItem
<View style={{ height: `93%` }}>
<FlatList
contentContainerStyle={{ minHeight: `100%` }}
scrollEnabled={true}
...props
renderItem={({item}) => (
<View style={{ flex: 1 }}>
...
</View>
)}
I had the same problem. What I did was to provide a marginBottom to the parent view of the FlatList with size that is equivalent (or a little larger) than the size of the rendered item .
<View style={{marginBottom: HEIGHT_OF_CELL + 60, flexGrow:1}}>
<FlatList
keyExtractor={(item, index) => index.toString()}
data={posts}
renderItem={renderItem}
/>
</View>
I method I used to resolve this is by setting the parent view to the FlatList's background color to a visible color(e.g red). Then adjust the margin bottom for that view so that it is large enough for all the contents in the FlatList to be viewed.
In my case the parent view was wrapped in another view which I could not give the flex: 1 style to.
use dimensions for parent view and set height as given:
const screenHeight = Dimensions.get('window').height - 100
<View style={{...styles.container,height:screenHeight}}>
....All child components
</View>
adding flex:1 to my render item worked for me
<FlatList
data={data}
renderItem={({ item }) => (
<ListItem
onPress={() => console.log('ok')}
bottomDivider
rightTitle={
<Divider style={{ marginBottom: 4, backgroundColor: item.status, width: '50%', height: '11%', borderRadius: 10 }} />
}
titleProps={{ numberOfLines: 1 }}
rightSubtitle={item.date}
rightTitleStyle={{ fontFamily: 'poppins' }}
rightSubtitleStyle={{ fontFamily: 'poppins' }}
titleStyle={{ fontFamily: 'poppins' }}
subtitleStyle={{ fontFamily: 'poppins' }}
title={item.device}
subtitle={item.type}
leftAvatar={{ source: item.icon, rounded: false }}
**style={{ flex: 1 }}**
/>
)}
keyExtractor={item => item._id}
ListHeaderComponent={renderHeader}
ListFooterComponent={renderFooter}
onEndReached={handleLoadMore}
onEndReachedThreshold={0.2}
/>