CODEWITHSUNDEEP
classswift3swift-protocolsxcode8
Dravidian
Dravidian

Reputation: 9945

Add listener to a variable in a global instance of a class

I have a User Class which holds the details of that particular user, authentication status and a flag that tells me wether or not my user's data has been retrieved: 

// Users class

class user_Global {

   static let shared_Instance = user_Global()
   var is_Retrieved : Bool = false
   var is_Authenticated : Bool = false
   var user : users_Status = users_Status.init(name: "Global user", is_Master: false, EY_ID : "N/A", ey_Email : "N/A", UUID : "N/A")
    }

// Structure

struct users_Status{

var user_Name : String!
var is_User_Master : Bool!
var user_EY_Email : String!
var user_UUID : String!
var user_EY_ID : String!

init(name : String!, is_Master : Bool!, EY_ID : String! ,ey_Email : String!, UUID : String!){

    self.user_Name = name
    self.is_User_Master = is_Master
    self.user_EY_Email = ey_Email
    self.user_UUID = UUID
    self.user_EY_ID = EY_ID

   }

}

Going further in my app, i have few functionalities that i only allow for the authenticated user, The problem is that this status can change any time. How do i add a listener to that variable i.e is_Authenticated in my user_Global.shared_Instance.. to perform an operation on my subsequent classes.

I did think of using protocol-delegate method but couldn't get it operational. Somehow my protocol conforming classes are not calling the function of the protocol.

EDIT 1

class user_Global {

var refresh_Delegate : user_Data_Refresh!

static let shared_Instance = user_Global()
var is_Retrieved : Bool = false
var is_Authenticated : Bool = false{

    didSet{

        print(oldValue)
        print(is_Authenticated)

    }

}
var user : users_Status = users_Status.init(name: "Global user", is_Master: false, EY_ID : "N/A", ey_Email : "N/A", UUID : "N/A"){

    didSet{

        if user.is_User_Master == true{

            print("The user has MASTER Permissions")
            user_Data_Refresh.refresh_User_State() // This is the line where is get an error

        }else{

            print("Master Auth was terminated!")

        }
    }

 }


}

// Protocol : 

protocol user_Data_Refresh {

   func refresh_User_State()

}

PS: user is updated once i retrieve the value from my Database. To confirm that data is already retrieved is_Retrieved flag.

Upvotes: 0

Views: 518

Answers (1)

Oleg Danu
Oleg Danu

Reputation: 4159

Use property observers for this:

class user_Global {

    static let shared_Instance = user_Global()
    var is_Retrieved : Bool = false
    var is_Authenticated : Bool = false {
        didSet {
            // Your code here
        }
    }
    var user : users_Status = users_Status.init(name: "Global user", is_Master: false, EY_ID : "N/A", ey_Email : "N/A", UUID : "N/A")
}

Update You have a protocol definition there and user_Global defines a delegate which conforms to this protocol var refresh_Delegate : user_Data_Refresh!(PS: Delegates usually are optionals). The problem in the mentioned line:

user_Data_Refresh.refresh_User_State()

is that you do not use the delegate object to call the function, but instead you use its type, which is wrong. Replace it with 

refresh_Delegate.refresh_User_State()

and it should work.

Note: It looks like you are moving to Swift from backend development or C/C++ or something like that. Please take your time to revise Swift API design guidelines to get in touch more with naming conventions. Your code is hardly readable.

Upvotes: 1

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