swift - GRMustache - 子类上的 MustacheBox

Question

了解 GRMustache 和 Swift。

如果我有一个类和一个子类，其中父类实现了 MustacheBoxable，是否可以在子类上扩展 MustacheBox，而无需重复 MustacheBox 的整个变量设置？

class Host: MustacheBoxable {
  var name: String?
}
extension Host {
    var mustacheBox: MustacheBox {
      return Box([
         "name": self.name
      ])
    }
}

class TopGearHost: Host {
  var drives_slowly: Bool = false
}
extension Host {
    var mustacheBox: MustacheBox {
      //how would I go about NOT doing this?
      return Box([
          "name": self.name,  // don't want to repeat this guy
          "drives_slowly": self.drives_slowly
      ])
    }
}

预先感谢您的任何提示/指导:)

Answer 1

虽然我认为这并不优雅，但我确实找到了一种方法来实现这一点。

• 创建变量(“boxedValues”)用于从父类导出属性
• 父级上的 MustacheBox 返回装箱变量
• 子类可以访问父类(“boxedValues”)变量并添加值
• mustacheBox 的实现继续适用于子类

class Host: MustacheBoxable {
    var name: String?
}
extension Host {
    var boxedValues: [String:MustacheBox] {
        return [ "name" : self.name ]
    }
    var mustacheBox: MustacheBox {
        return Box(boxedValues)
    }
}
class TopGearHost: Host {
    var drives_slowly: Bool = false
}
extension Host {
    override var boxedValues: [String:MustacheBox] {
        var vals = super.boxedValues
        vals["drives_slowly"] = Box(self.drives_slowly)
        return vals
    }
}