Javascript Articles - Page 140 of 607

Loading indicator is used when we want to tell the user the request they made on the UI will take time. In case the user has clicked on the submit button after filling the form, or has clicked on the search button to get some data.ReactNative offers an ActivityIndicator component that has different ways to show loading indicators on the UI.The basic ActivityIndicator component is as follows −To work with ActivityIndicator you need to import it as follows −import { ActivityIndicator} from 'react-native';Here are some of the important properties available with ActivityIndicator.Sr.NoProps & Description1animatingFor animating the loading indicator.It takes boolean ... Read More

Once ReactNative is installed on your system, you should get a default code in App.js as follows −import React from 'react'; import { StyleSheet, Text, View } from 'react-native'; export default class App extends React.Component {    render() {       return (                       Open up App.js to start working on your app!                Changes you make will automatically reload.                   Shake your phone to open the developer menu.             ... Read More

To load data from the server you can make use of the fetch API that is similar to XMLHttpRequest or any other networking api’s.It is very easy to make a request to the server using fetch. Take a look at the following code −fetch('https://jsonplaceholder.typicode.com/posts/1')    .then((response) => response.json())    .then((responseJson) => console.log(responseJson));In above code we are fetching the JSON file https://jsonplaceholder.typicode.com/posts/1 and printing the data to the console. The simplest call to fetch() API takes in one argument i.e the path you want to fetch and it returns a promise with response.The fetch api returns a promise with http response, ... Read More

The Alert component helps to show a dialog box i.e., a pop up to the user with a title, message, buttons to know the confirmation from the user based on the message displayed.The basic component of Alert is as follows −Alert.alert('yourtile', 'yourmessage', [yourbuttons], ‘options’)To work with Alert component you need to import it as follows −import { Alert } from 'react-native';To get the pop-up you just have to call the Alert.alert() function. There are four params the alert() takes and it is title, message, buttons and options. The title is mandatory param and rest are optional.Here is a simple example ... Read More

The increase in the popularity of IOs and Android apps nowadays there are lots of companies building apps and want them to develop in a faster way. A fully native app is getting very expensive as it requires separate teams to work on iOS and Android. ReactNative is a good solution to this as the app developed in react native can be run on ios and android.React Native is an open source mobile development framework that app developers prefer, to build an app that is cost effective and also saves time.React Native was a Facebook's hackathon project that was meant ... Read More

An interface that helps to render the lists in sections. Some of the important features of SectionList are −Header/Footer support to the ListHeader/Footer support to the sectionScroll LoadingPull to refreshFully cross-platformThe basic SectionList component looks as follows −To work with SectionList import the component as shown below −import { SectionList } from "react-native";Here is a list of important properties available on a SectionList −PropsDescriptionrenderItemIs the default function that renders the item in the section. It returns a react element.The render function will be passed to sectionlist like an object with following keys −'item'(object) - the item object'index' (number) - Index ... Read More

FlatList is a container that can be used to load the list items. It offers header and footer support, multiple column support, comes with vertical/horizontal scrolling, lazy loading etc.Here are some important features of FlatList −Comes with scroll loadingAble to adjust the scroll by using ScrolltoIndex supportComes with header and footer supportMultiple column supportCross platformConfigurable viewability callbacksThe Basic structure of FlatList is as follows − item.id} />FlatList is implemented from the VirtualizedList component that takes care of displaying a limited number of items that will fit in the current view port of your mobile screen. The rest of the data ... Read More

Styling your app can be done as follows −Using Stylesheet componentUsing Inline stylesUsing Stylesheet componentReact native Stylesheet component comes very handy and neat when you want to apply styling to your app. To work with Stylesheet component first import it as shown below −import { StyleSheet } from 'react-native';You can create the style using Stylesheet component as follows −const styles = StyleSheet.create({    container: {       flex: 1,       marginTop: StatusBar.currentHeight || 0,    },    item: {       margin: 10,       padding: 20,       marginVertical: 8,       ... Read More

Props are properties that help to modify the react component. The component created can be used with different parameters using props concept. With props you can pass the information from one component to another and at the same time re-use the component as per your requirement.You will be familiar with props if you are well versed with ReactJS, the same concepts follow in React Native.Let us take a look at an example that explains what props are.Example 1: Props inside React Native Built-in ComponentsConsider the Image component −The style and source are properties i.e props for the image component. The ... Read More

The most important core components in react native are as follows −React Native componentAndroid Native ViewIOS Native ViewWeb BrowserDescriptionView - When the app is seen in Android device the component will be changed to when the app is seen in IOS device the component will be changed to When seen in a web browser the component will be changed to tagIt is the core container that supports flexbox layout. It also manages touch handling.Text - When the app is seen in Android device the component will be changed to when the app is seen in ... Read More