Is it possible to trigger a segue from a qr code reading in swift

Question

I had a quick ios swift programing question. Is it possible to trigger a segue from a QR code reading in swift? I looked it up on Google and found this app coda tutroial. I still don't understand how I would go about doing it with a segue. could someone explain how they did it in there app? Thanks!

UPDATE

thanks Christian Woerz for the useful tip!

I found out how to do it!

when this function:

func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!) {

// Check if the metadataObjects array is not nil and it contains at least one object.
if metadataObjects == nil || metadataObjects.count == 0 {
    qrCodeFrameView?.frame = CGRectZero
    messageLabel.text = "No QR code is detected"
    return
}

// Get the metadata object.
let metadataObj = metadataObjects[0] as AVMetadataMachineReadableCodeObject

if metadataObj.type == AVMetadataObjectTypeQRCode {
    // If the found metadata is equal to the QR code metadata then update the status label's text and set the bounds
    let barCodeObject = videoPreviewLayer?.transformedMetadataObjectForMetadataObject(metadataObj as AVMetadataMachineReadableCodeObject) as AVMetadataMachineReadableCodeObject
    qrCodeFrameView?.frame = barCodeObject.bounds;

    if metadataObj.stringValue != nil {
        messageLabel.text = metadataObj.stringValue
    }
  }
}

is fired do a performSegueWithIdentifier(_ identifier: String?, sender sender: AnyObject?) inside the function like this

func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!) {

// Check if the metadataObjects array is not nil and it contains at least one object.
if metadataObjects == nil || metadataObjects.count == 0 {
    qrCodeFrameView?.frame = CGRectZero
    messageLabel.text = "No QR code is detected"
    return
}

// Get the metadata object.
let metadataObj = metadataObjects[0] as AVMetadataMachineReadableCodeObject

if metadataObj.type == AVMetadataObjectTypeQRCode {
    // If the found metadata is equal to the QR code metadata then update the status label's text and set the bounds
    let barCodeObject = videoPreviewLayer?.transformedMetadataObjectForMetadataObject(metadataObj as AVMetadataMachineReadableCodeObject) as AVMetadataMachineReadableCodeObject
    qrCodeFrameView?.frame = barCodeObject.bounds;

    if metadataObj.stringValue != nil {
        messageLabel.text = metadataObj.stringValue
    }
  }

**performSegueWithIdentifier(_ identifier: String?, sender sender:  AnyObject?)**

}

and pass in the Identifier of the segue like

Identifier: thetransition

untested code but logic there :)

Answer 1

Yes it is possible.

But we can only give you a general answer, because there are many different ways and libraries to read a QR-code. But to give you a little example, you could use the QR code reader from this tutorial. If you read a QR code with the code provided in this tutorial, a method will get called which receives the data of the QR code. In the tutorial it is captureOutput.

Then in this method you can add code to perform a segue if the method is called.