如何使用NSUserDefaults与包含应用程序共享数据？ - 今日Extension Widget

Question

I am trying to create a Today Extension Widget which displays stored data in the widget.

Here's what I have done;

• Added New Today Widget Target
• Set up UIViewController for widget
• Enable App Groups for both the app and extension

Now I have hit a road block, I am unsure the best way to retrieve and display a simple array of fetched data.

There is very little Swift tutorials and they often do not use core data.

In the main app project I fetch the array.

 let moc = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext
 let request = NSFetchRequest(entityName: "Objects")
    do {
      try
      self.objectsArray = moc.executeFetchRequest(request) as! [Objects]
    } catch {

    }

How can I use NSUserDefaults to store the objects array and then use in the today widget extension ? Or Even an array of string values.

Answer 1

1) Get url to your database

var containerPath: String = NSFileManager.defaultManager().containerURLForSecurityApplicationGroupIdentifier‌​(YOUR_SECURITY_APP_GROUP).path 

var sqlitePath: String = "(containerPath)/("database.sqlite")"

2) Create Persistent Store Coordinator as you do in parent app.

3) Set it for your Managed Object context

context = NSManagedObjectContext()
context.persistentStoreCoordinator = coordinator

4) Retrieve objects as you do in your parent app

let moc = context
let request = NSFetchRequest(entityName: "Objects")
do {
  try self.objectsArray = moc.executeFetchRequest(request) as! [Objects]
} catch {}

Answer 2

If you set up the App Groups correct and added the same group for both Application and Extension you can use NSUserDefaults. Just for instance, to write something from the app, you need:

static func setSharedScoreNumber(score: Int) {
    let defaults = UserDefaults(suiteName: "group.bubblewrapSharedDefaults") // this is the name of the group we added in "App Groups"
    defaults?.set(String(score), forKey: "score")
    defaults?.synchronize()
}

And to read from Todays Extension:

private func getScore() -> String {
    let defaults = UserDefaults(suiteName: "group.bubblewrapSharedDefaults")
    defaults?.synchronize()
    return String(describing: defaults!.object(forKey: "score") ?? "0")
}

Here's the complete guide how to do so.