How to check if a file exists in the Documents directory in Swift?

Question

How to check if a file exists in the Documents directory in Swift?

I am using [ .writeFilePath ] method to save an image into the Documents

Answer 1

Nowadays (2016) Apple recommends more and more to use the URL related API of NSURL, NSFileManager etc.

To get the documents directory in iOS and Swift 2 use

let documentDirectoryURL = try! NSFileManager.defaultManager().URLForDirectory(.DocumentDirectory, 
                                 inDomain: .UserDomainMask, 
                        appropriateForURL: nil, 
                                   create: true)

The try! is safe in this case because this standard directory is guaranteed to exist.

Then append the appropriate path component for example an sqlite file

let databaseURL = documentDirectoryURL.URLByAppendingPathComponent("MyDataBase.sqlite")

Now check if the file exists with checkResourceIsReachableAndReturnError of NSURL.

let fileExists = databaseURL.checkResourceIsReachableAndReturnError(nil)

If you need the error pass the NSError pointer to the parameter.

var error : NSError?
let fileExists = databaseURL.checkResourceIsReachableAndReturnError(&error)
if !fileExists { print(error) }

Swift 3+:

let documentDirectoryURL = try! FileManager.default.url(for: .documentDirectory, 
                                in: .userDomainMask, 
                    appropriateFor: nil, 
                            create: true)

let databaseURL = documentDirectoryURL.appendingPathComponent("MyDataBase.sqlite")

checkResourceIsReachable is marked as can throw

do {
    let fileExists = try databaseURL.checkResourceIsReachable()
    // handle the boolean result
} catch let error as NSError {
    print(error)
}

To consider only the boolean return value and ignore the error use the nil-coalescing operator

let fileExists = (try? databaseURL.checkResourceIsReachable()) ?? false