React Native FlatList: Everything You Need to Know about using it

You might have come across apps with lists, which could be anything from users to contacts, news, and activities. A list is an essential component of an app, as it helps customers in decision-making in various aspects of their lives. Therefore, you are building an app for your business, do not forget to implement this list.

While it is easy to implement, displaying such a long list may seem unfeasible. But if you are using React Native, there is good news. React Native comes with different ways of displaying data. ScrollView is the most common option in React Native to display a scrolling data list.

It also has other options to represent a list of data, including FlatList and SelectionList. In this post, we will explain everything you need to know about React Native FlatList. So, before you hire a React Native developer for your project, you should know how React Native FlatList works.

• What is React Native FlatList?

When it comes to the FlatList component, it is the easiest way to create a scrolling list of large quantities of data. It uses the ScrollView component in the process. In addition to this, it comes with a simple API. If you know how the ListView works, you will not have difficulties using FlatList because they are very similar. Moreover, you can skip formatting the data and render it right away. Are you wondering how? Well, thanks to its props, we will explain later.

• How does React Native FlatList work?

The best thing about the FlatList component is it works well with large quantities of data likely to change with time. Your potential React Native mobile app development company must know its two primary props, like data and renderItem. The former prop is a series of data that helps create the list, whereas the latter is a callback function. It is used for accepting a list from the data prop and rendering it.

If you want to display your data using a particular style, follow this method that helps you create styling through the renderItem prop. For example: renderItem={this.RenderStyling})

Apart from this, numerous prop options are available to help you in the development process. Some of them are listed below.

• KeyExtractor
  • ItemSeparatorComponent
  • ListFooterComponent
  • ListHeaderComponent
  • OnRefresh and refreshing
  • intialNumToRender
  • onEndReached and onEndReachedThreshold

Now, the question arises of what makes FlatList the most preferred option for creating a list of data. Let us dig deep to find out about it.

• What are the benefits of using React Native FlatList?

• Instead of a lot of code, FlatList requires two props to start. Hence, it saves you time.
  • It is a high-performing component, especially if you want to render a large quantity of data or several items in one list.
  • The function works similarly for mobile platforms as well.

• Using React Native FlatList: A complete guide

1. React and React-native methods – To begin the process, we need React and some of React-native methods.

import React from ‘react’;

import { StyleSheet, Text, View, SafeAreaView, FlatList, Platform, SafeAreaProvider} from “react-native”;

• Import FlatList – The next step involves importing FlatList from the React Native module to display your data. For this, you need to use props – data and renderItemComponent.

For example, you have a data array with a list of countries. Now, pass this through the data prop and render it using renderItem.

import { FlatList, Text, View } from “react-native”;

// …

const App = () => {

    constructor(props) {

        super(props);

        this.state = {

            countries: data

        }

    }

    render() {

        return (

            <View style={{ flex: 1 }}>

• Use KeyExtractor – There are unique keys that help the FlatList component to track the items. They play an essential role in improving the performance and efficiency.

render() {

 return (

  <SafeAreaView>

    <FlatList

     data={this.state.data}

     renderItem={item => this.renderItemComponent(item)}

       keyExtractor={item => item.id.toString()}

     />

  </SafeAreaView>)

• Implement ItemSeparatorComponent – Use the ItemSeparatorComponent prop to add a line to separate a list of items. Additionally, you add a new prop in the FlatList component “itemSeparatorComponent.”

• Incorporate header – The header is a component at the top of the list. The steps to add a header is similar to the separator. A function renderHeader is used to render the interface of the header. After this, the function passes to the React Native FlatList component for rendering it as a Header.

• Add footer – If you want to add footer, you should follow the same steps as the header. However, we have to write two more classes for the footer in the stylesheet. You can also use an alternative listFooterComponent to add the footer.

• Implement Pull to refresh – You need two props for adding pull to refresh, including refreshing and onRefresh. The first helps in tracking whether the view needs an update or not. On the other hand, onRefresh is a function that ensures loading new data and updating items in FlatList.

That is everything about the React Native FlatList component, from how it works to benefits and implementation. Well, this is how React Native app development companies in India fetch data from API and display a list of items on your React Native app.

If you are searching for the best React Native mobile app development company, get in touch with SoftProdigy. Hire our dedicated React Native developers to ensure high-quality services.