Setting filesystem metadata from Swift

Question

TomE OP

Created Nov ’20

Replies 5

Boosts 0

Views 1.7k

Participants 4

Hi,

I'm trying to convert the following code snippet to Swift:

Code Block NSURL* pathURL = [NSURL fileURLWithPath:path];
BOOL success = [pathURL setResourceValue:tags forKey:NSURLTagNamesKey error:&outError];

However, it looks like the equivalent is now blocked in the API definition - in the Xcode 12 Swift API declaration .tagNames (and allValues) are get-only properties of URLResourceValues (according to StackOverflow, they were mutable in the past).

Code Block extension URL {
    func setTagNames(_ tags: [String] ) {
        var values = URLResourceValues()
        values.tagNames = tags // Error here: Cannot assign to property: tagNames is get-only
        try self.setResourceValues( values )
    }
}

How can I set the tagNames?

Thanks,
Thomas

Boost

Answer 1

OOPer OP

Nov ’20

Seems Foundation team has changed the API without showing alternatives...

Can you try something like this?:

Code Block extension URL {
    mutating func setTagNames(_ tags: [String] ) throws {
        self.setTemporaryResourceValue(tags, forKey: .tagNamesKey)
        let values = try self.resourceValues(forKeys: [.tagNamesKey])
        try self.setResourceValues(values)
    }
}

(Sorry, I do not have enough time to explore now.)

0

Answer 2

DTS Engineer OP

Apple

Nov ’20

It’s not at all clear why this has changed. Please file a bug about it and post your bug number, just for the record.

Notably, the underlying NSURL property, NSURLTagNamesKey, is still documented as read/write. This gives you a potential workaround, namely:

Code Block  func setTagNames(_ names: [String], for url: URL) throws {
    let u = url as NSURL
    try u.setResourceValue(names, forKey: .tagNamesKey)
}

Unfortunately I don’t have time to test this right now, so I’m not sure if this’ll actually work. Let us know how you get along.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@apple.com"

1

Answer 3

TomE OP

Nov ’20

Thanks for your replies! Bug is filed: FB8910801

The NSURL workaround actually works, the temporaryResourceValue not.

0

Answer 4

OOPer OP

Nov ’20

The NSURL workaround actually works, the temporaryResourceValue not.

Thanks for testing and sharing the result. Seems using NSURL is the only workaround.
Hope this issue is fixed soon.

0

Answer 5

DTS Engineer OP

Apple

Mar ’22

See this thread for the latest.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

0