Swift / Cocoa: How to watch folder for changes?
Marc T's answer still works and seems to be the easiest solution for this.
To make it work I needed to add the following line (could be at the init() of ObservingClass):
NSFileCoordinator.addFilePresenter(self)
You can do this using NSFilePresenter. The observing class must conform to NSFilePresenter as shown below.
The presentedItemURL would point to the folder you want to observe. If there is a change in the folder presentedSubitemDidChangeAtURL get called. The code snipped below could give you an idea how it can work.
class ObservingClass: NSObject, NSFilePresenter {
lazy var presentedItemOperationQueue = NSOperationQueue.mainQueue()
var presentedItemURL:NSURL?
func presentedSubitemDidChangeAtURL(url: NSURL) {
let pathExtension = url.pathExtension
if pathExtension == "png"{
refreshImages()
}
}
func refreshImages(){
let path = snapshotPath
var isDirectory: ObjCBool = ObjCBool(false)
if NSFileManager.defaultManager().fileExistsAtPath(path!, isDirectory: &isDirectory){
if isDirectory{
do {
let list = try NSFileManager.defaultManager().contentsOfDirectoryAtPath(path!) as Array<String>
for filePath in list {
if filePath.hasSuffix(".png"){
if let snapshot = snapshotAtPath(path! + "/" + filePath){
newSnapshotArray += [snapshot]
}
}
}
} catch {
// error handling
}
}
}
}
}
Best wishes.