How to create a PDF417 barcode

Swift version: 5.4

Paul Hudson @twostraws May 28th 2019

PDF417 barcodes - most frequently seen on boarding passes at airports, but also seen in digital postage stamps and other places – are built right into iOS. This function below accepts a string as its only parameter and returns a UIImage containing the PDF417 barcode representing that string:

func generatePDF417Barcode(from string: String) -> UIImage? {
    let data = string.data(using: String.Encoding.ascii)

    if let filter = CIFilter(name: "CIPDF417BarcodeGenerator") {
        filter.setValue(data, forKey: "inputMessage")
        let transform = CGAffineTransform(scaleX: 3, y: 3)

        if let output = filter.outputImage?.transformed(by: transform) {
            return UIImage(ciImage: output)
        }
    }

    return nil
}

let image = generatePDF417Barcode(from: "Hacking with Swift")