AWS Cognito check and get users

Question

I'm building an iOS App that is using Amazon MobileHub. Currently it's associated with Cognito and the sign up and sign in flow works great.

What I'm trying to achieve is for one user to be able to add another user as a friend so to speak. To make that possible, I need to check if a user with a specific username exists and if it does, get some attributes such as the name of that target user.

I've tried to use the get user > get details function but it gives me an error Authentication delegate not set .

Here's the code I used:

var pool: AWSCognitoIdentityUserPool?
let user = pool?.getUser(usernameField.text!)

self.pool = AWSCognitoIdentityUserPool.init(forKey: AWSCognitoUserPoolsSignInProviderKey)

user?.getDetails().continueWith { (task: AWSTask<AWSCognitoIdentityUserGetDetailsResponse>) -> Any? in
  if let error = task.error as NSError? {
    print("ERROR: " + error.localizedDescription)
    return ""
  }

  print(task.result)
  return ""
}

An approach I thought of was to store the username and the attributes I want to access to DynamoDB and then access it there but that will just create double unnecessary entries.

Answer 1

The issue you'll run into is that user attributes aren't publicly visible. Only the user who has signed in can call GetUser. If it's a back end process, you could do this via the AdminGetUser operation, but this looks client side so I wouldn't recommend that. The only real way around this would be to do what you suggested at the bottom of your post, ultimately.