Performing Action When a Barcode Is Scanned

[yeahdongcn]

Performing Action When a Barcode Is Scanned

[yeahdongcn]

func performQR(){
    dispatch_async(dispatch_get_main_queue(), { () -> Void in
        self.performSegueWithIdentifier("toQR", sender: self)
    })
}

You need to switch to main thread to perform UI related operations.

[yeahdongcn]

The barcodesHandler was designed non thread safe, because we may perform some actions which may take long time.

[yeahdongcn]

Could you try the code I provided?

[drewantonich]

Thank you very much for the reply. I am unable to test the code tonight, but I will tomorrow.

[drewantonich]

I tested the code and it does perform the segue. My only issue now is that the segue is performed multiple times and doesn't just stop after a valid scan happened. Is there a way to stop the scanning process immediately after a valid scan took place?

self.barcodesHandler = { barcodes in
    for barcode in barcodes {
        println("Barcode found: type=" + barcode.type + " value=" + barcode.stringValue)

        if let builtObject = self.ObjectHelper.validateAndBuild(barcode,
            scannedData: barcode.stringValue){ // If built object is valid
                self.performQR() // End scanning here and perform segue once
        }
    }
}

[yeahdongcn]

You can add a break after you call self.performQR()

[drewantonich]

Unfortunately, adding the break still causes multiple segues to occur. A solution I found is to add self.session.stopRunning() before self.performQR() and then add a break. Is it safe to stop the session like this?

self.barcodesHandler = { barcodes in
    for barcode in barcodes {
        println("Barcode found: type=" + barcode.type + " value=" + barcode.stringValue)
        if let builtObject = self.ObjectHelper.validateAndBuild(barcode,
            scannedData: barcode.stringValue){ // If built object is valid
                self.finalObject = builtObject // Assign finalObject for segue purposes
                self.session.stopRunning()
                break
        }
        else {
            self.displayInvalidScan()
        }
    }
    self.handleSegue()
}

[yeahdongcn]

Yeah, you're right, I forgot this line.

[drewantonich]

I posted this conversation to SO to be more reachable.

[yeahdongcn]

Great, thank you!

[Gerst20051]

👍