Save file in document directory in swift 3?

TechChain picture TechChain · Jun 20, 2017 · Viewed 74.3k times · Source

I am saving files in a document directory in swift 3 with this code:

fileManager = FileManager.default
// let documentDirectory = fileManager?.urls(for: .documentDirectory, in: .userDomainMask).first as String
var path = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as String
path = path + name

let image = #imageLiteral(resourceName: "Notifications")
let imageData = UIImageJPEGRepresentation(image, 0.5)
let bool = fileManager?.createFile(atPath: path, contents: imageData, attributes: nil)

print("bool is \(bool)")
return true

But as you can see, I am not using filemanager to get document directory path as filemanager gives only URL not string.

Questions:

  • How to get string from file manager?
  • Is there any chance of crash in my code?

Answer

vadian picture vadian · Jun 20, 2017

Please think the other way round.

URL is the recommended way to handle file paths because it contains all convenience methods for appending and deleting path components and extensions – rather than String which Apple has removed those methods from.

You are discouraged from concatenating paths like path = path + name. It's error-prone because you are responsible for all slash path separators.

Further you don't need to create a file with FileManager. Data has a method to write data to disk.

let fileManager = FileManager.default
do {
    let documentDirectory = try fileManager.url(for: .documentDirectory, in: .userDomainMask, appropriateFor:nil, create:false)
    let fileURL = documentDirectory.appendingPathComponent(name)
    let image = #imageLiteral(resourceName: "Notifications")
    if let imageData = image.jpegData(compressionQuality: 0.5) {
        try imageData.write(to: fileURL)
        return true
    }
} catch {
    print(error)
}
return false