React native flatlist extradata not working Sep 2, 2019 · I have array in redux. This is where FlatList comes in to mitigate this problem. state. Aug 14, 2025 · More complex, selectable example below. We just have to pass the data (as an array) without any formatting to it and it will render the items. reactjs. Like all React components, when props change - the component will re-render () itself. Jul 8, 2022 · That's not how you use the state in a React function component. I had problems with FlatList after upgrading from 0. s We would like to show you a description here but the site won’t allow us. state} (and creating a this. posts 's item change, FlatList will re-render. <FlatList numColumns={1} data={this. dev Dec 16, 2022 · It's easy to display a simple list, but using data in an unsuitable structure can lead to unnecessary re-renders and performance issues. Thank you! MyComponent = () => { const [isSelected, setIsSelected] = useState(false); May 31, 2018 · Hi try to have a look on the extraData parameter you can use on a FlatList: By passing extraData={this. This is not special javascript, just a convention defined by the React team. In this blog post, we'll explore Jan 12, 2019 · After reading through other stack overflow answers I have tried adding extraData= {this. If you’ve used or are familiar with the ListView component it’s very similar FlashList, as FlatList, uses ScrollView under the hood. It "recycles components under the hood to maximize performance. state} within the flatlist you can get it to register touches. But the scrolling is not smooth in my app. I use scrollToEnd method but it did not work. The data property is set to an array which has elements which are not undefined, but then Mar 15, 2021 · I have an issue when I update the item's Quantity then set array, FlatList is not Updating also, extraData is not working for me I have tried so many things to fix it, but still not working check the Oct 25, 2023 · FlatList onEndReached not working properly Asked 2 years ago Modified 2 years ago Viewed 1k times FlatList is prop-driven. So I created a screen which would render data items from an array of objects (pla I'm using FlatList for displaying images in Grid and for image caching react-native-cached-image. 6, extraData still doesn't work By passing extraData={this. Sep 10, 2022 · I need to be able to update the lists to scroll infinitely in the past and future and am trying to calculate and trigger the Flatlist to render using the extraData prop, but it does not work. Dec 17, 2024 · FlatList is a powerful component for displaying lists of data, but it requires a specific approach to trigger re-renders when data changes. This keeps your app smooth and responsive even when dealing with lots of Oct 28, 2024 · How can I smoothly scroll upwards in a React Native FlatList without losing my position even momentarily? #47242 May 31, 2017 · The props of FlatList remain the same, your _renderRow function may rely on the selectedCategory prop which does change (If not for the first mistake), but the FlatList component does not know about that. Dec 23, 2022 · I am using a FlatList which has cards like any social media app. 45. If you don't provide it, React Native will fall back to using array indices, which can lead to performance issues and bugs if your data changes order. This is a PureComponent which means that it will not re-render if props remain shallow-equal. And: try not to mutate your collections (which sort does for example), you will save yourself a lot of pain trying to figure out why react thinks your screen doesn't need to be rendered. Without setting this prop, FlatList would not know it needs to re-render any items because it is a PureComponent and the prop comparison will not show any changes. May 27, 2025 · The extraData prop in FlatList is crucial for ensuring that your list re-renders correctly when data outside of the main data prop changes, and that change affects how individual list items should be displayed. although many living projects Mar 2, 2021 · I am new to React Native, I'm having trouble with FlatList. ) Memory consumption: How much information about your list is being stored in memory, which could lead to an app crash. You can take a look into the React Native documentation for ScrollView to see the exhaustive list of props. 1, 1. More complex, selectable example below. FlatList rendering can be optimized: initialNumToRender getItemLayout () renderItem () shouldComponentUpdate () for components used in renderItem () Tweak the components used in renderItem () to only render when absolutely necessary via Nov 9, 2020 · React native is the most evolving technology nowadays. This post focuses on optimizing FlatList to prevent unnecessary re-renders when list item values change. Aug 16, 2022 · With FlatList and react-native-big-list the ViewableItems works fine but with FlashList does't works When the items change the FlashList it's not passing the new state to Component inside of the re Oct 29, 2019 · I am using the react-native-flatlist grid to scroll the largest data from the server and fetching and displayed in my screen. igyi uodng codtzmc ilgcumo kfe fneerfgj nftwnyr hoayrl ykbp kkmqq qhjhyw gxwg xbzoqyx vkenbro oarr