MacOS how is KIND implemented-CodePudding

I am trying to write a piece of code that instead of checking file extensions for the many different types of image files, but instead looking at the file attributes. What I can’t figure out from searching the docs is if KIND:Image is really a file attribute or simply a construct Apple created in the FinderApp to make things easier for the user.

I wrote a snippet that pulls the attributes for files with an extension of jpeg and for each file the fileType is returned as NSFileTypeRegular.

let attr = try filemanager.attributesOfItem(atPath: pathConfig "/" file) as NSDictionary

if file.hasSuffix(ext) {

   print ("Adding \(file) [ \(attr.fileSize()) \(attr.fileType())]")

   print ( attr.fileModificationDate() )
}

Does anybody know if MacOS retains an attribute for the category a file falls in to. e.g. IMAGE, DOCUMENT etc.

CodePudding user response：

To achieve a functionality similar to the Kind search tag in Finder you can use UTType (Link to reference).

You can get the UTType of a file by initialising it with the file extension:

let fileType = UTType(filenameExtension: fileURL.pathExtension)

The cool thing about UTTypes is that they can have a hierarchy, so UTType.jpeg is a subtype of UTType.image.

If you want to check if a file is any kind of image, you can do it like this

let isImage = fileType.conforms(to: .image)

You can check the list for the kind of types you want to support as "Kinds", and filter using those UTTypes

CodePudding user response：

This was my final solution based on the information provided by @EmilioPelaez I am not completely comfortable with Swift especially the unwrapping operations so if the code looks weird that might be why.

func imagesInDir(path: String?) -> [String] {
    if let path {
        let filemanager: FileManager = FileManager()
        let files = filemanager.enumerator(atPath: path)
        var array = [String]()
        var urlFile: NSURL
        
        while let file = files?.nextObject() as? String {
            urlFile = NSURL(fileURLWithPath: file, isDirectory: false)
            if (urlFile.isFileURL) {
                if let pathExt = urlFile.pathExtension {
                    if let fileType = UTType(filenameExtension: pathExt) {
                        let isImage = fileType.conforms(to: .image)
                        if (isImage){
                            array.append(file)
                            print ("\(array.count)  \(fileType)")
                        }
                    }
                }
            }
        }
    }
    return array
}