Access data outside its method in Swift - ios

Question

I am having trouble with my swift code. The problem is that I need to have my prepareForSegue outside of the method, so the data inside the method cannot be used outside and in my prepareForSegue. How can I use the data outside so it will work in my prepareForSegue?
I am giving you all of my code, since it can be usefull all of it :-)
The error is marked with ////-- --//// down in the bottom of the code. It says: use of unresolved identifier "metadataObj".
import UIKit
import AVFoundation
class ViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
#IBOutlet weak var messageLabel:UILabel!
var captureSession:AVCaptureSession?
var videoPreviewLayer:AVCaptureVideoPreviewLayer?
var qrCodeFrameView:UIView?
$$$$$$$$ var metadataObj: AVMetadataMachineReadableCodeObject?
let supportedBarCodes = [AVMetadataObjectTypeQRCode, AVMetadataObjectTypeCode128Code, AVMetadataObjectTypeCode39Code, AVMetadataObjectTypeCode93Code, AVMetadataObjectTypeUPCECode, AVMetadataObjectTypePDF417Code, AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeAztecCode]
override func viewDidLoad() {
super.viewDidLoad()
let captureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
do {
let input = try AVCaptureDeviceInput(device: captureDevice)
captureSession = AVCaptureSession()
captureSession?.addInput(input)
let captureMetadataOutput = AVCaptureMetadataOutput()
captureSession?.addOutput(captureMetadataOutput)
captureMetadataOutput.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
captureMetadataOutput.metadataObjectTypes = supportedBarCodes
videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
videoPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
videoPreviewLayer?.frame = view.layer.bounds
view.layer.addSublayer(videoPreviewLayer!)
captureSession?.startRunning()
view.bringSubviewToFront(messageLabel)
qrCodeFrameView = UIView()
if let qrCodeFrameView = qrCodeFrameView {
qrCodeFrameView.layer.borderColor = UIColor.greenColor().CGColor
qrCodeFrameView.layer.borderWidth = 2
view.addSubview(qrCodeFrameView)
view.bringSubviewToFront(qrCodeFrameView)
}
} catch {
print(error)
return
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]?, fromConnection connection: AVCaptureConnection!) {
if metadataObjects == nil || metadataObjects!.count == 0 {
qrCodeFrameView?.frame = CGRectZero
messageLabel.text = "No barcode/QR code is detected"
return
}
let metadataObj = metadataObjects![0] as! AVMetadataMachineReadableCodeObject
if supportedBarCodes.contains(metadataObj.type) {
let barCodeObject = videoPreviewLayer?.transformedMetadataObjectForMetadataObject(metadataObj)
qrCodeFrameView?.frame = barCodeObject!.bounds
if metadataObj.stringValue != nil {
dispatch_async(dispatch_get_main_queue()){
self.performSegueWithIdentifier("SendDataSegue", sender: self)
}
}
}
}
if let metadataObj = metadataObj {
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "SendDataSegue" {
if let sendToDetailViewController = segue.destinationViewController as? DetailViewController {
sendToDetailViewController.viaSegue = metadataObj.stringValue
}
}
}
}
}
Hope you guys can help me.

Answer 1

Your metadataObj is declared inside of captureOutput() function. You need to move the declaration outside, same place as you have your captureSession etc.
For example:
var metadataObj: AVMetadataMachineReadableCodeObject?
Then you can use it in both prepareForSegue and captureOutput(). Check for nil before using in prepareForSegue:
if let metadataObj = metadataObj {
// use metadataObj
}