在初始化期间使用覆盖的静态属性 [英] Using an overriden static property during initialization

问题描述

我想创建一个具有静态属性的类，子类可以覆盖该属性，该属性将用于初始化实例。到目前为止，我已经尝试完成以下操作：

I would like to create a class with a static property that subclasses can override, which would be used to initialize instances. So far, I've tried to accomplish this like this:

import Cocoa

class A: NSObject {
    class var staticProperty: String {
        return "A"
    }

    var property: String = A.staticProperty
}

class B: A {
    override class var staticProperty: String {
        return "B"
    }
}

这不起作用，因为 B（）。property 仍返回 A 。如何更改此代码，以使属性包含子类指定的值？任何帮助将不胜感激！

This does not work, since B().property still returns "A". How could I change this code so that property contains the value specified by the subclass? Any help would be appreciated!

编辑
我想初始化属性的值为 staticProperty ，因此它也可能像这样：

Edit I would like to initialize property with the value of staticProperty, so this could also look like this:

var property: SomeClass = SomeClass(A.staticProperty)

但是，此初始化仍应将 A 用于A类，将 B 用于B类。

But then, this initialization should still use "A" for class A, and "B" for class B.

编辑2（在@RakeshaShastri发表评论之后）
对于我的特定用例，我需要属性来

编辑3
总之，我正在尝试构建一个领域模型类，它与其他模型之间有许多关系。对于这些模型（它们非常相似），我试图创建一个包含共享功能的超类，其中还包括反向关系。因此，我想拥有一个静态属性，该属性包含第一个模型中其他任何一个模型的密钥，然后使用该密钥名称初始化LinkingObjects属性。由于Realm不允许延迟或计算，因此我不能在这里使用这些功能。

Edit 3 In short, I'm trying to build a Realm model class which has a few to-many relationships to other models. For these models (which are quite similar), I'm trying to create a superclass which contains the shared functionality, amongst which is also the inverse relationship. Therefore, I want to have a static property which contains the key in the first model to either of the other models, and then initialize a LinkingObjects property using this key name. Since Realm does not allow this to be lazy or computed, I cannot use these functionalities here.

推荐答案

如果您继承自NSObject，为什么？不使用它吗？

If you inherit from NSObject why not using it ?

import Cocoa

class A: NSObject {
    var property: String
    public override init() {
        let str = type(of: self).perform(#selector(getter: type(of: self).staticProperty))?.takeUnretainedValue() as! String
        property = str

    }

    @objc class var staticProperty: String {
        return "A"
    }

}

class B: A {
    override class var staticProperty: String {
        return "B"
    }
}

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