Writing a simple 'hello world' PDF page in swift for macos and it's coming out blank

Question

So it seems like almost all the examples out there for writing PDF content in a swift app are for ios. But I need this to run under macos. So for example, I can't use any of the UI functions like UIGraphicsRenderer, etc. I have tried to piece together a test application whose only function is to print 'hello world', but I must be doing something wrong. The PDF does get created and saved, but it has no content. Any advice would be welcome. Here's the print function:

import Foundation
import PDFKit

func printPDF() {
    
    let localURL = FileManager.default.currentDirectoryPath
    let url = URL(fileURLWithPath: localURL).appendingPathComponent("tv-schedule-for-today.pdf")
 
    var pdfDoc: PDFDocument? = PDFDocument()
    
    let page: PDFPage? = PDFPage()
    var mediaBox: CGRect = page!.bounds(for: .mediaBox)
    
    guard let currentContext = CGContext(url as CFURL, mediaBox: &mediaBox, nil) else {
        return
    }
    var context: CGContext? = currentContext

    context!.beginPDFPage(nil)

    let attributes = [
          NSAttributedString.Key.font: NSFont.boldSystemFont(ofSize: 72)
        ]
    let text = "Hello World!"
    text.draw(at: CGPoint(x: 200, y: 300), withAttributes: attributes)

    context!.endPDFPage()

    pdfDoc!.insert(page!, at: 0)
        
    context!.closePDF()

    pdfDoc!.write(to: url as URL)
    
    context = nil

}

Update:

There's an answer here that resolves my problem. Kudos to @Willeke for pointing it out to me.

[https://stackoverflow.com/questions/44640022/draw-on-a-pdf-using-swift-on-macos][1]

Turns out I had seen it earlier but made an error implementing it. Going over it again I realized I hadn't connected the CGContext with the NSGraphicsContext. Also starting the actual render with page.draw. My corrected code is below, and it works very well now. Thanks everyone! :)

import Foundation
import PDFKit

func printPDF() {
    
    let localURL = FileManager.default.currentDirectoryPath
    let url = URL(fileURLWithPath: localURL).appendingPathComponent("tv-schedule-for-today.pdf")
 
    let pdfDoc: PDFDocument? = PDFDocument(url: url)
    //var pageCount = 0  // for future use with custom pagination
    
    let page: PDFPage? = pdfDoc!.page(at: 0)!
    
    var mediaBox: CGRect = page!.bounds(for: .mediaBox)
    
    guard let currentContext = CGContext(url as CFURL, mediaBox: &mediaBox, nil) else {
        return
    }
    var context: CGContext? = currentContext
    
    let nscontext = NSGraphicsContext(cgContext: context!, flipped: false)
    NSGraphicsContext.current = nscontext

    context!.beginPDFPage(nil)
    
    do {
        page!.draw(with: .mediaBox, to: context!)

        let attributes = [
              NSAttributedString.Key.font: NSFont.boldSystemFont(ofSize: 36)
            ]
        let text = "I'm a simpler PDF!"
        text.draw(at: CGPoint(x: 100, y: 100), withAttributes: attributes)
    
    }

    context!.endPDFPage()

    NSGraphicsContext.current = nil

    context!.closePDF()
    
    context = nil

}