What you need to do to personalize the Document Based APP template

What you need to do to personalize the Document Based APP template?

1. Use your UIDocument subclass instead of the stubbed out one.

2. Use your document-viewing MVC code(already using UIDocument) instead of stub

3. Add code to UIDocumentBrowserViewController subclass to …

   a. configure the UIDocumentBrowserViewController (allow multiple selection? creation of new documents? etc)

   b. specify the url of a template document to copy to create new documents

   c. present your document-viewing MVC modally given the url of a document

4. Update the Document Types in Project Settings to be your types(instead of public.image)

Steps 1 and 2

As long as you properly implement UIDocument in your MVC, this is no extra work

Step 3a: Configuring the UIDocumentBrowserViewController

This happens in its viewDidLoad …

override func viewDidLoad() {
    super.viewDidLoad()
    delegate = self   //the guts of making UIDocumentBrowserViewController work are in its delegate methods
    allowsDocumentCreation = true
    allowsPickingMultipleItems = true
    browserUserInterfaceStyle = .dark
    view.tintColor = .white
}
// set these as you wish

Step 3b: Specifying the “new document” template URL

This happens in this UIDocumentBrowserViewController delegate method …

func documentBrowser(_ controller: UIDBVC,
didRequestDocumentCreationWithHandler handler: @escaping (URL?, UIDBVC.ImportMode) -> Void
){
    let url:URL? = ...   //where your blank, template document can be found
    importHandler(url, .copy or .move)
}

Usually you would specify .copy, but you could create a new template each time and .move.

Likely you would have some code here that creates that blank template (or ship with your app)

Step 3c: Presenting your document MVC modally

The Xcode template stubs out a function called presentDocument(at: URL) to do this …

func presentDocument(at url: URL) {
    let story = UIStoryboard(name: "Main", bundle: nil)
    if let docvc = story.instantiateViewController(withIdentifier: "DocVC") as? DocVC {
        docvc.document = MyDocument(fileURL: url)
        present(docvc, animated: true)
    }
}

We can call this function anything you want

The point is that it takes a URL to one of your documents and show it

The Xcode template then calls this from the appropriate delegate methods in UIDBVC

That’s all you have to do to get UIDBVC working

Step 4: Specifying your types

Unless your app opens public.image files, you’ll need to change that in Project Settings