CODEWITHSUNDEEP
javascriptandroidandroid-camerazxingzxing-js
techietalk
techietalk

Reputation: 119

ZXing force rear camera on android device?

I am building a project that uses the ZXing library to scan barcodes. Currently the code I have is working for iOS device opening up the rear camera but when testing using android device it opens up the front camera. Is there a way I can always force the rear camera to be used on any device? Please see working code below:

    <script type="text/javascript">
        window.addEventListener('load', function () {
            let selectedDeviceId;
            const codeReader = new ZXing.BrowserMultiFormatReader();
            console.log('ZXing code reader initialized');
            codeReader.getVideoInputDevices()
                .then((videoInputDevices) => {
                    if (videoInputDevices.length < 1) {
                        console.log('No video devices found');
                        return;
                    }

                    selectedDeviceId = videoInputDevices[0].deviceId;

                    codeReader.decodeFromVideoDevice(selectedDeviceId, 'video', (result, err) => {
                        if (result) {
                            console.log(result);
                            var barcode = result;
                            //this.window.alert(barcode);
                            if (String(barcode).charAt(0) == 'L') {
                                document.getElementById('result').textContent = result.text;
                                document.getElementById('result').style.color = "green";
                                var previousurl = document.referrer;
                                window.location.href = previousurl + "&BarCode=" + result.text;
                            }
                            else {

                                document.getElementById('result').textContent = result.text;
                                document.getElementById('result').style.color = "red";
                                window.alert("Incorrect Barcode scan value.  Please try again.")
                            }

                        }
                        if (err && !(err instanceof ZXing.NotFoundException)) {
                            console.error(err);
                            document.getElementById('result').textContent = err;
                        }
                    })
                    console.log(`Started continous decode from camera with id ${selectedDeviceId}`)
                })
                .catch((err) => {
                    console.error(err)
                })
        })

    </script>

Upvotes: 4

Views: 4393

Answers (1)

aryanknp
aryanknp

Reputation: 1167

remove selectedDeviceId and use undefined

codeReader.decodeFromVideoDevice(undefined, 'video', (result, err) => {
                        if (result) {

documentation says if you use undefined it will automatically choose the camera, preferring the main (environment facing) camera if more are available.

The error occurs because codeReader.getVideoInputDevices() returns different result

Upvotes: 6

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