@react-native-community/netinfo / Expo / Github / Npm / Alter Native / Connection / Speed / Internet Connection / NativeModule RNCNetInfo is null

@react-native-community/netinfo / Expo / Github / Npm / Alter Native / Connection / Speed / Internet Connection / NativeModule RNCNetInfo is null :

Install the library using either Yarn:

yarn add @react-native-community/netinfo

or npm:

npm install --save @react-native-community/netinfo

Using React Native >= 0.60

Linking the package manually is not required anymore with Autolinking.

  • iOS Platform:$ npx pod-install # CocoaPods on iOS needs this extra step
  • Android Platform with AndroidX:Modify your android/build.gradle configuration:buildscript { ext { buildToolsVersion = "xx.yy.zz" minSdkVersion = xyz compileSdkVersion = xyz targetSdkVersion = xyz androidXCore = "1.7.0" // <-- Add this. Check versions here: https://developer.android.com/jetpack/androidx/releases/core }
  • macOS Platform:Autolinking is not yet available on macOS. See the Manual linking steps for macOS below.

Manually link the library on macOS

  • Windows Platform:Autolinking automatically works on RNW >= 0.63.

Minimum supported versions for windows

  • react-native-windows 0.63 or newer
  • MSVC build tools v142 (included in Visual Studio 2019) or newer
  • x86, x64, or arm64 are supported, arm (32-bit) is not supported

React Native Compatibility

To use this library you need to ensure you are using the correct version of React Native. We support react-native 0.60+ with auto-linking.

If you are using a version of React Native that is lower than 0.60 check older versions of this README for details, but no support will be provided.

Browser Compatilibity

The web implementation heavily depends on the Network Information API which is still an is an experimental technology and thus it’s not supported in every browser. If this API is not available the library will safely fallback to the old onLine property and return basic connection information.

Migrating from the core react-native module

This module was created when the NetInfo was split out from the core of React Native. To migrate to this module you need to follow the installation instructions above and then change you imports from:

import { NetInfo } from "react-native";

to:

import NetInfo from "@react-native-community/netinfo";

Note that the API was updated after it was extracted from NetInfo to support some new features, however, the previous API is still available and works with no updates to your code.

Usage

Import the library:

import NetInfo from "@react-native-community/netinfo";

Subscribe to network state updates:

// Subscribe
const unsubscribe = NetInfo.addEventListener(state => {
  console.log("Connection type", state.type);
  console.log("Is connected?", state.isConnected);
});

// Unsubscribe
unsubscribe();

Get the network state once:

NetInfo.fetch().then(state => {
  console.log("Connection type", state.type);
  console.log("Is connected?", state.isConnected);
});

API

Methods

configure()

Configures the library with the given configuration. You only need to supply the properties which you want to change from the default values.

Note that calling this will stop all previously added listeners from being called again. It is best to call this right when your application is started to avoid issues.

Example:

NetInfo.configure({
  reachabilityUrl: 'https://clients3.google.com/generate_204',
  reachabilityTest: async (response) => response.status === 204,
  reachabilityLongTimeout: 60 * 1000, // 60s
  reachabilityShortTimeout: 5 * 1000, // 5s
  reachabilityRequestTimeout: 15 * 1000, // 15s
  reachabilityShouldRun: () => true,
  shouldFetchWiFiSSID: true, // met iOS requirements to get SSID. Will leak memory if set to true without meeting requirements.
  useNativeReachability: false
});

addEventListener()

Subscribe to connection information. The callback is called with a parameter of type NetInfoState whenever the connection state changes. Your listener will be called with the latest information soon after you subscribe and then with any subsequent changes afterwards. You should not assume that the listener is called in the same way across devices or platforms.

ParameterTypeDescription
listener(state: NetInfoState) => voidThe listener which will be called whenever the connection state changes

Example:

// Subscribe
const unsubscribe = NetInfo.addEventListener(state => {
  console.log("Connection type", state.type);
  console.log("Is connected?", state.isConnected);
});

// Unsubscribe
unsubscribe();

useNetInfo()

React Hook which can be used to get access to the latest state. It returns a hook with the NetInfoState type.

Example:

import {useNetInfo} from "@react-native-community/netinfo";

const YourComponent = () => {
  const netInfo = useNetInfo();

  return (
    <View>
      <Text>Type: {netInfo.type}</Text>
      <Text>Is Connected? {netInfo.isConnected?.toString()}</Text>
    </View>
  );
};

You can optionally send configuration when setting up the hook. Note that configuration is global for the library, so you shouldn’t send different configuration for different hooks. It is instead recommended that you called NetInfo.configure() once when your project starts. The hook option is only provided as a convinience.

const YourComponent = () => {
  const netInfo = useNetInfo({
    reachabilityUrl: 'https://clients3.google.com/generate_204',
    reachabilityTest: async (response) => response.status === 204,
    reachabilityLongTimeout: 60 * 1000, // 60s
    reachabilityShortTimeout: 5 * 1000, // 5s
    reachabilityRequestTimeout: 15 * 1000, // 15s
    reachabilityShouldRun: () => true,
    shouldFetchWiFiSSID: true, // met iOS requirements to get SSID
    useNativeReachability: false
  });

  // ...
};

fetch()

Returns a Promise that resolves to a NetInfoState object.

Example:

NetInfo.fetch().then(state => {
  console.log("Connection type", state.type);
  console.log("Is connected?", state.isConnected);
});

You can optionally send an interface string so the Promise resolves to a NetInfoState from the NetInfoStateType indicated in interface argument.

NetInfo.fetch("wifi").then(state => {
  console.log("SSID", state.details.ssid);
  console.log("BSSID", state.details.bssid);
  console.log("Is connected?", state.isConnected);
});

refresh()

Updates NetInfo’s internal state, then returns a Promise that resolves to a NetInfoState object. This is similar to fetch(), but really only useful on platforms that do not supply internet reachability natively. For example, you can use it to immediately re-run an internet reachability test if a network request fails unexpectedly.

Example:

NetInfo.refresh().then(state => {
    console.log("Connection type", state.type);
    console.log("Is connected?", state.isConnected);
});

This will also update subscribers using addEventListener and/or useNetInfo.

Troubleshooting

Errors when building on Android

Errors while running Jest tests

If you do not have a Jest Setup file configured, you should add the following to your Jest settings and create the jest.setup.js file in project root:

setupFiles: ['<rootDir>/jest.setup.js']

You should then add the following to your Jest setup file to mock the NetInfo Native Module:

import mockRNCNetInfo from '@react-native-community/netinfo/jest/netinfo-mock.js';

jest.mock('@react-native-community/netinfo', () => mockRNCNetInfo);

Issues with the iOS simulator

There is a known issue with the iOS Simulator which causes it to not receive network change notifications correctly when the host machine disconnects and then connects to Wifi. If you are having issues with iOS then please test on an actual device before reporting any bugs.

Switching between different Wi-Fi does not send events in iOS

The SCNetworkReachability API used in iOS does not send events to the app in the background, so switching from one Wi-Fi network to another when your App was in background will not send an event and your network state will be out of sync with device state. To be sure you have up to date status when your app is in foreground again, you should re-fetch state each time when App comes to foreground, something like this:

  useEffect(() => {
    const subAppState = AppState.addEventListener("change", async (nextAppState) => {
      if (IS_IOS_DEVICE && nextAppState=='active') {
        let newNetInfo = await NativeModules.RNCNetInfo.getCurrentState('wifi');
        //your code here 
      }
    });
    const unsubNetState = NetInfo.addEventListener(state => {
        //your code here
    });
    return () => {
        if (subAppState) {
            subAppState.remove();
        }
        unsubNetState();
    };
  },[]);

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