Listener for Internet Connectivity

I'm currently working on an application that scans 2D barcodes to retrieve data from the URLs provided by these codes. When a user loses internet connection, the application stores the URLs using AsyncStorage. However, I am facing an issue where I need to implement a listener that triggers a specific method once the internet connection is regained. Can someone suggest the best approach for implementing such a connection listener?

Edit:
I attempted to use a NetInfo EventListener, but it seems like I might be using it incorrectly because the function gets called every time, even when there's no change in internet status.

_connectionHandler = (e) => {
    this.setState({ cameraActive: false })
    NetInfo.getConnectionInfo().then((connectionInfo) => {

        if (connectionInfo.type === "none"){
            console.log("No internet")
            dataArray.push(e.data)
            let barcodeData_delta = {
                data: dataArray
            }

            AsyncStorage.mergeItem(STORAGE_KEY, JSON.stringify(barcodeData_delta));

            NetInfo.isConnected.addEventListener(
                'connectionChange',
                this._handleConnectionChange(e.data)
            );
            this.setState({ cameraActive: true })
        } else {
            console.log("Internet available -> Going to read barcode now")
            this._handleBarCodeRead(e.data);
        }
    })
}

Answer №1

For those using React Native, the NetInfo documentation provides a helpful guide on how to add a listener for connection changes and take action accordingly.

Simply add a handler to the isConnected property:

NetInfo.isConnected.addEventListener(
  'connectionChange',
  _connectionHandler
);

The _connectionHandler function is responsible for handling the change in connection status. Make sure to update your setState with care when implementing this function.

_connectionHandler = (isConnected) => {
    this.setState({ cameraActive: false })
        if (!isConnected){
            console.log("No internet")
            dataArray.push(e.data)
            let barcodeData_delta = {
                data: dataArray
            }
            AsyncStorage.mergeItem(STORAGE_KEY, JSON.stringify(barcodeData_delta));                   
            this.setState({ cameraActive: true })
        } else {
            console.log("Internet available -> Going to read barcode now")
            this._handleBarCodeRead(e.data);
        }
    })
}

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