Swift 4: Change / Clear PDFView content

Question

I want to use PDFView framework in Swift 4. (https://developer.apple.com/documentation/pdfkit/pdfview)

The following function receives a path to a PDF document. If the path is valid, the PDF file is successful shown. A problem occurs, when I call openMe(path: String) twice. In this case, the old content is still there and the new content is added. I just want to change the old content with the new content.

private var pdfData: NSData? = nil

func openMe(path: String) {
   let fileManager = FileManager.default

   if fileManager.fileExists(atPath: path){
       let url = NSURL.fileURL(withPath: path)
       pdfData = NSData(contentsOfFile: path)
       let pdfView = PDFView(frame: self.view.frame)
       pdfViewController?.pdfViewControllerInformsMeasurementDataViewController = self
       pdfView.document = PDFDocument(url: url)
       pdfView.autoScales = true
       pdfView.maxScaleFactor = 0.5
       pdfView.minScaleFactor = pdfView.scaleFactorForSizeToFit
       pdfView.autoresizingMask = [.flexibleWidth, .flexibleHeight]

       self.pdfViewController?.view.addSubview(pdfView)
       self.show(self.pdfViewController!, sender: nil)
    }
}

EDIT

Refer to excitedmicrobe's answer: I just changed the code like shown in the answer but the distance between the navigation controller and the PDFView differs.

Fist openMe call:

Second openMe call:

Answer 1

In that case, you would need to make your pdfView global:

Before viewDidLoad() add the following:

var pdfView = PDFView()

override func viewDidLoad() {
    super.viewDidLoad()

    // ....
}

And edit your code openMe() to:

func openMe(path: String) {
     if self.pdfViewController?.view.subviews.contains(pdfView) {
          self.pdfView.removeFromSuperview() // Remove it
      } else {
          // Do Nothing
      }

     let fileManager = FileManager.default

   if fileManager.fileExists(atPath: path){
       let url = NSURL.fileURL(withPath: path)
       pdfData = NSData(contentsOfFile: path)
       self.pdfView = PDFView(frame: self.view.frame)
       pdfViewController?.pdfViewControllerInformsMeasurementDataViewController = self
       pdfView.document = PDFDocument(url: url)
       pdfView.autoScales = true
       pdfView.maxScaleFactor = 0.5
       pdfView.minScaleFactor = pdfView.scaleFactorForSizeToFit
       pdfView.autoresizingMask = [.flexibleWidth, .flexibleHeight]

       self.pdfViewController?.view.addSubview(pdfView)
       self.show(self.pdfViewController!, sender: nil)
     }
}

Answer 2

In this situation, you have to achieve document using try? Data(contentsOf: url).

 if let url = URL.init(string: path), let data = try? Data(contentsOf: url), let pdfDocument = PDFDocument.init(data: data){
            
            
            pdfView.displayMode = .singlePageContinuous
            pdfView.autoScales = true
            pdfView.displayDirection = .vertical
            pdfView.document = pdfDocument
            //                        
        }