SwiftUI print a view - swift

Question

I have an old iOS app that uses UIKit and Objective C which I am currecntly porting to SwiftUI and Swift. Everything was going great and I am loving Swift and SwiftUI. The app is pretty much done but the app relies on the user being able to print and/or save the main view as a PDF. I just can't figure out how to access a view in swiftui in order to convert it to a PDF. Here is my existing/working objective-c code.
- (IBAction)actionPrint:(id)sender {
// CREATE CLEAR BACKGROUND
[legMain setBackgroundColor:[UIColor clearColor]];
// SCROLL TO BASE POSITION
[legMain scrollRectToVisible:CGRectMake(1, 1, 1, 1) animated:NO];
// RESET ZOOM
SnapPanel *myObject = [self fGetObject];
myObject.zoom = [NSNumber numberWithDouble:1.0];
[self fSave];
// RECORD FRAME SIZE AND SET TO CONTENT SIZE
double dWidth = legMain.frame.size.width;
double dHeight = legMain.frame.size.height;
[legMain setFrame:CGRectMake(legMain.frame.origin.x, legMain.frame.origin.y, legMain.contentSize.width, legMain.contentSize.height)];
// GET VIEW AS NSDATA FOR PDF
NSMutableData *pdfData = [NSMutableData data];
CGRect pageSize = CGRectMake(0.0, 0.0, 8.5 * 72.0, 11.0 * 72.0);
UIGraphicsBeginPDFContextToData(pdfData, pageSize, nil);
CGContextRef pdfContext = UIGraphicsGetCurrentContext();
// CREATE A SINGLE PAGE PDF
UIGraphicsBeginPDFPage();
[legMain.layer renderInContext:pdfContext];
UIGraphicsEndPDFContext();
// CREATE PRINT CONTROLLER
UIPrintInteractionController *pc = [UIPrintInteractionController sharedPrintController];
void (^completionHandler)(UIPrintInteractionController *, BOOL, NSError *) =
^(UIPrintInteractionController *pic, BOOL completed, NSError *error) {
if (!completed && error){
NSLog(#"Print error: %#", error);
}
};
// SETUP PRINT CONTROLLER
[pc setShowsNumberOfCopies:YES];
[pc setShowsPageRange:YES];
[pc setShowsPaperSelectionForLoadedPapers:YES];
pc.printingItem = pdfData;
// DISPLAY CONTROLLER DIALOG
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
[pc presentFromRect:texName.frame inView:viewMain.superview
animated:YES completionHandler:completionHandler];
} else {
[pc presentAnimated:YES completionHandler:completionHandler];
}
// RESET BACKGROUND COLOUR AND FRAME SIZE
[legMain setBackgroundColor:[UIColor colorWithRed:.95 green:.95 blue:.95 alpha:1.0]];
[legMain setFrame:CGRectMake(legMain.frame.origin.x, legMain.frame.origin.y, dWidth, dHeight)];
}
legMain is the view that I am adjusting and eventually converting to a PDF. I have managed to port most of this code untill I reach line 26 where I need to render the view. I don't even know where to begin to get an instance of my view.

Answer 1

Having access to hosting window as described in How to access own window within SwiftUI view? you can get main UIView from any of your SwiftUI view as
let mainView = hostingWindow?.rootViewController.view
but for printing I would probably use dedicated view as below (to avoid affecting UI view)
if let hostingController = hostingWindow?.rootController as UIHostingController {
let printingView = UIHostingController(rootView: hostingController.rootView).view
// ... do anything with printingView here, because it will have
// a copy of SwiftUI rootView
}
Update: to the details in comment (hosting window is not needed in this case)
VStack {
PrintableView(arg: value) // << need to be made undependable, so all
// parameters should be passed via arguments
}
then on Print action it could be like
Button("Print") {
let printingView = UIHostingController(rootView: PrintableView(arg: value)).view
// do anything printing related with `printingView` here
}