Inheritance.md

Inheritance

Overriding properties

Seems a bit strange at first but the way you override properities is to defined a stored property and then override it with a computed property.

class ActivationService {

    var url: String = ""

class OrderDetailsService: ActivationService {

    override var url: String {
        get {
            return "https://foo/bar"
        }
        set {
            // nop
        }
    }

It needs to be a var. You need to override the get and the set. And if you don't want to override the setter you can just define a getter in the base class like this.

class ActivationService {

    var url: String {
        get {
            return ""
        }
    }

Note: You can't override a stored property with another stored property. Swift doesn't let you do that. What you can do however is switch from a stored property to a computed property. In otherwords just provide a different getter implementation. It's a subtle but important point.

Links that help

• Inheritance