Hello,
I'm trying to rewrite a NSDocument app using SwiftUI. The file on disk is practically a renamed Zip (files are pretty large).
Using NSDocument it is easy cause I can get an URL and then read/write from/to that URL.
Using ReferenceFileDocument apparently this is not possible cause I'm forced to use FileWrapper for reading/writing and I cannot load the whole file into memory cause it would be too big.
Are there any solutions to use URLs with ReferenceFileDocument?
Thanks,
Giacomo
Did you ever find a solution to this?
Not really. I managed to obtain the url of the file with the following trick. I can try to find something similar to write the file back, but I'm afraid it might be unstable or unpredictable.
import ObjectiveC
// Declare a global var to produce a unique address as the assoc object handle
private var AssociatedObjectHandle: UInt8 = 0
extension FileWrapper {
var fileURL: URL? {
get {
return objc_getAssociatedObject(self, &AssociatedObjectHandle) as? URL
}
set {
objc_setAssociatedObject(self, &AssociatedObjectHandle, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC)
}
}
@objc convenience init(trick url: URL, options: ReadingOptions) throws {
try self.init(trick: url, options: options)
self.fileURL = url
}
}
struct Trick {
static func execute() {
let aClass: AnyClass = FileWrapper.self
let originalMethod = class_getInstanceMethod(aClass, #selector(FileWrapper.init(url:options:)))
let swizzledMethod = class_getInstanceMethod(aClass, #selector(FileWrapper.init(trick:options:)))
guard let originalMethod = originalMethod, let swizzledMethod = swizzledMethod else {
return
}
method_exchangeImplementations(originalMethod, swizzledMethod)
}
}