How to specify a filename when saving pdf document to iOS Files App?

Question

Using the PDFKit I have created a pdf document within my app. I can successfully show it in a preview and from the preview controller I use the following code to present the user the share actions:

@objc func shareAction(_ sender: UIBarButtonItem)
{
    if let data = documentData
    {
        let vc = UIActivityViewController(activityItems: [data], applicationActivities: [])
        present(vc, animated: true, completion: nil     
    }
}

documentData contains the created pdf document.

When the user selects "Save to Files" the document gets the default name "PDF Document.pdf", which the user can change.

How can I provide a different default filename?

Answer 1

Not a real answer but rather a workaround that I figured out:

Rather than using the in-memory-copy data of the PDF, I can write it to the apps tmp folder:

var fileURL : URL?
do
{
    let filename = "myfilename.pdf"
    let tmpDirectory = FileManager.default.temporaryDirectory
    fileURL = tmpDirectory.appendingPathComponent(filename)
    try data.write(to: fileURL!)
}
catch
{
    print ("Cannot write PDF: \(error)")
}

The share action would then look like:

@objc func shareAction(_ sender: UIBarButtonItem)
{
    if let url = fileURL
    {
        let vc = UIActivityViewController(activityItems: [url], applicationActivities: [])
        present(vc, animated: true, completion: nil     
    }
}

Now the user gets "myfilename.pdf" shown as default filename when he chooses the "Save to Files" action.

Answer 2

Sorry, this is not an answer but hopefully somebody get some hints from this.

I am also struggling from this problem. I believe you should set the title as a metadata of the PDF file.

Below is my code trying to set the title base on this document but it doesn't work!

Please somebody let me know what I'm missing.

let title = "My Title" as CFString

let metaData = [
  kCGPDFContextTitle: title
]

let format = UIGraphicsPDFRendererFormat()
format.documentInfo = metaData as [String: Any]

let renderer = UIGraphicsPDFRenderer(bounds: myCGRect, format: format)

let data = renderer.pdfData { (context) in
    // draw PDF pages
}

Answer 3

Just an additional help.

You'd better delete the PDF files in tmp dir at appropriate time.

I call this func when viewController dismisses.

FYI

func deleteAllPDFs() {
    let predicate = NSPredicate(format: "self ENDSWITH '.pdf'")
    let defaultFileManager = FileManager.default

    do {
        let tmpDirURL = defaultFileManager.temporaryDirectory
        let contents = try defaultFileManager.contentsOfDirectory(atPath: tmpDirURL.path)
        let pdfs = contents.filter { predicate.evaluate(with: $0) }
        try pdfs.forEach { file in
            let fileUrl = tmpDirURL.appendingPathComponent(file)
            try defaultFileManager.removeItem(at: fileUrl)
        }
    }
    catch {
        print ("Failed to delete PDF with error: \(error)")
    }
}