Here is an Example of React Native NetInfo. React Native NetInfo exposes information about online/offline status. NetInfo notifies continuously about the network state whether it is online or offline.
Information about the net connection is very helpful when you are making an application which only works in online mode. The best example that you have seen is the YouTub app which will run smoothly and if you unexpectedly goes offline it generates a bottom snack alert to notify about the offline state.
Note: While getting internet connection information using NetInfo we attach a call back function with it. NetInfo provides the network information in this callback function but we can’t say it will call the function once or twice so there is no pattern that can define the number of calls from the NetInfo. Yeah, it is very sure it will call the function immediately after network state changes but still can say it will inform just once so you have to make your own logic with React Native state to handle the situation.
In this example, we will print the state of internet connection on console.
Under the Lean Core Project NetInfo has been moved to its new home @react-native-community/react-native-netinfo after the launch of React Native 0.59. If you are using React Native >= 0.59 then please follow the instruction for React Native >= 0.59.
To Import NetInfo in Code
For React Native < 0.59
1 | import { NetInfo } from 'react-native' |
After React Native >= 0.59
1 | import { NetInfo } from '@react-native-community/react-native-netinfo' |
Get NetInfo Using
1 2 3 4 5 6 7 | NetInfo.getConnectionInfo().then((connectionInfo) => { console.log( 'Initial, type: ' + connectionInfo.type + ', effectiveType: ' + connectionInfo.effectiveType); }); |
Listener for the change of NetInfo
1 2 3 4 | NetInfo.addEventListener( 'connectionChange', this.handleFirstConnectivityChange ); |
To Make a React Native App
Getting started with React Native will help you to know more about the way you can make a React Native project. We are going to use react-native init to make our React Native App. Assuming that you have node installed, you can use npm to install thereact-native-cli command line utility.
Open the terminal and go to the workspace and runnpm install -g react-native-clireact-native init ProjectNameAdditional Step for React Native >= 0.59
as we are using @react-native-community/react-native-netinfo in React Native >= 0.59 then we have to install and link the dependency.
Installation of Dependency
To use NetInfo we need to install @react-native-community/react-native-netinfo dependency.
To install this open the terminal and jump into your project using
1 | cd ProjectName |
Run the following command to install
1 | npm install @react-native-community/react-native-netinfo --save |
This command will copy all the dependency into your node_module directory.
–save is optional, it is just to update the @react-native-community/react-native-netinfo dependancy in your package.json file.
Linking of Dependency
After installing the dependency you need to link it with your project using
1 | react-native link @react-native-community/react-native-netinfo |
After linking the dependency if you face Could not Compile Settings File project/android/settings.gradle error while building and installing the project then you can find the solution here.
Open App.js in any code editor and replace the code with the following code.
App.js
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 | //This is an example code for Net Info// import React, { Component } from 'react'; //import react in our code. //For React Native >= 0.59 import { NetInfo } from '@react-native-community/react-native-netinfo' import { AppState, Text } from 'react-native'; //For React Native < 0.59 //import { AppState, Text, NetInfo } from 'react-native'; export default class App extends Component { state = { appState: AppState.currentState, }; componentDidMount() { NetInfo.getConnectionInfo().then((connectionInfo) => { console.log( 'Initial, type: ' + connectionInfo.type + ', effectiveType: ' + connectionInfo.effectiveType); }); NetInfo.addEventListener( 'connectionChange', this.handleFirstConnectivityChange ); } handleFirstConnectivityChange(connectionInfo) { console.log('First change, type: ' + connectionInfo.type + ', effectiveType: ' + connectionInfo.effectiveType); } render() { return ( <Text style={{ marginTop: 30, padding: 20 }}> NetInfo Example. Please open debugger to see the log </Text> ); } } |
Permission to Access Network State and other configurations for Android
We are accessing the network state so we need to add some permission in AndroidManifest.xml file (For Android) after ejecting the project from expo environment. On devices before SDK version API 23, the permissions are automatically granted if they appear in the manifest but after SDK version 23 android applies new permissions model. For more about the permission, you can see React Native Android Permission.
So we are adding going to add the following permission in the AndroidMnifest.xml
1 | <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> |
By adding permission in AndroidManifest.xml you are able to access ACCESS_NETWORK_STATE of your devices.
To Run the React Native App
Open the terminal again and jump into your project using.cd ProjectNamereact-native run-androidreact-native run-ios (macOS only).
That was the React Native NetInfo. If you have any doubt or you want to share something about the topic you can comment below or contact us here. The remaining components will be covered in the next article. Stay tuned!
Hope you liked it. 🙂
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