CODEWITHSUNDEEP
swiftprotocols
some_id
some_id

Reputation: 29896

Swift protocol for shared functionality

I have a number of objects, and each need to be locked until purchased.

Each of these objects (NSManaged) have a productName String and isPurchased Bool.

I wrote a function isLocked() which uses there properties as well an external check in a singleton.

How can this be combined into a protocol so that the protocol contains the isLocked function implementation and the objects can just adhere to the protocol and then call isLocked when needed?

Upvotes: 0

Views: 975

Answers (1)

kandelvijaya
kandelvijaya

Reputation: 1585

If im not mistaken this can be achieved with Default implementations in swift.

protocol Locakable {
 var productName: String { get }
 var isPurchased: Bool { get }

 func lock()
 func unlock()
}

extension Locakable {

     func isLocked() {
        if isPurchased {
           //do something
           //lock it
           unlock()
         } else {
           lock()
         }
    }
 }

For more info on what mixin or default implementation is then chek out this wiki page https://en.wikipedia.org/wiki/Mixin

However, note that isLocked() is dispatched statically. Comment if something is unclear.

You can also abstract the idea of locking and unlocking and write a default implementation on the protocol extension if possible. Or provide a customisation point like so.

class Item: Locakable {
var productName = "ItemName"
var isPurchased = false

init () {
    isLocked()
}

func lock() {

}

func unlock() {

}
}

Upvotes: 2

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