How to determine the date an app is installed or used for the first time?

Question

I\'m planning on opening up an in app store and I\'d like to give existing users some of the items for free.

I thought of releasing an update which would store some

Answer 1

App build date:

public var appBuildDate: Date {
  if let path = Bundle.main.path(forResource: "Info", ofType: "plist") {
    if let createdDate = try! FileManager.default.attributesOfItem(atPath: path)[.creationDate] as? Date {
      return createdDate
    }
  }
  return Date() // Should never execute
}

App installation date:

public var appInstallDate: Date {
  if let documentsFolder = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last {
    if let installDate = try! FileManager.default.attributesOfItem(atPath: documentsFolder.path)[.creationDate] as? Date {
      return installDate
    }
  }
  return Date() // Should never execute
}

Answer 2

My solution would be to check the last modified date of one of the files in the app bundle.

NSString *sourceFile = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"Icon.png"];

NSDate *lastModif = [[[NSFileManager defaultManager] attributesOfItemAtPath:sourceFile error:&err] objectForKey:NSFileModificationDate];

Answer 3

Using the creation date of Documents directory is the best solution so far. Reproducing it in Swift 4.2

var inferredDateInstalledOn: Date? {
    guard
        let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last,
        let attributes = try? FileManager.default.attributesOfItem(atPath: documentsURL.path),
        else { return nil }
    return attributes[.creationDate] as? Date
}

Answer 4

Here's a little safer approach, with out the force try and force unwrapping, and update to suit SWIFT 5:

if
    let urlToDocumentsFolder = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last,
    let installDateAny = (try? FileManager.default.attributesOfItem(atPath: urlToDocumentsFolder.path)[.creationDate]),
    let installDate = installDateAny as? Date
{
    print("This app was installed by the user on \(installDate)")
}