ios - Swift/NSMutableDisctionary init/如何使值可选

Question

为了将数据存储到我的 firebase 中，我使用以下代码:

class NewEventDate {

    private let firebase = FIRDatabase.database().reference().child("eventDates")
    let eventDictionary: NSMutableDictionary

    init (date: String, free: String, club: String) {

        eventDictionary = NSMutableDictionary(objects: [date, free, club], forKeys: ["date", "free", "club"])
    }

    func saveEventDate(backendlessUserObjectID: String, item: NSMutableDictionary) {

        let reference = firebase.child(backendlessUserObjectID)
        reference.setValue(item) { (error, ref) -> Void in
            if error != nil {
                SpeedLog.print("\(error)")
            }
        }
    }
}

调用者:

func saveDatesLoop() {

    for date in calendarView.selectedDates {
        saveDateToFirebase(formatter.stringFromDate(date), free: "true", club: "11er")
    }
}

func saveDateToFirebase(date: String, free: String, club: String) {

    var newEvent = NewEventDate?()
    newEvent = NewEventDate(date: date, free: free, club: club)
    newEvent?.saveEventDate(backendless.userService.currentUser.objectId, item: newEvent!.eventDictionary)
}

我希望 free 和 club 是可选的，所以我可以将它们设置为 nil ，如下所示: saveDateToFirebase(formatter.stringFromDate(date)，免费:nil，club:nil)

实现这一点的最佳实践是什么？非常感谢您的帮助。

PS:free:“true”，club:“11er”已硬编码以进行测试。

PPS:我尝试设置init(date:String，free:String？，club:String？)，但Xcode强制我稍后解开它们...

Answer 1

我可以通过一些解决方法将它们设为可选(以便能够将它们设置为零):

init (date: String, free: String?, club: String?, eventText: String?) {
    var localFree = ""
    var localClub = ""
    var localEventText = ""

    if let tempFree = free {
        localFree = tempFree
    }
    if let tempClub = club {
        localClub = tempClub
    }
    if let tempEventText = eventText {
        localEventText = tempEventText
    }

    eventDictionary = NSMutableDictionary(objects: [date, localFree, localClub, localEventText], forKeys: ["date", "free", "club", "eventText"])

}

现在我可以这样调用它:

func saveDateToFirebase(date: String, free: String?, club: String?, eventText: String?) {

    var newEvent = NewEventDate?()
    newEvent = NewEventDate(date: date, free: free, club: club, eventText: eventText)
    newEvent?.saveEventDate(backendless.userService.currentUser.objectId, date: date, item: newEvent!.eventDictionary)
}

如果我也想的话，最后让它们nil:

saveDateToFirebase(NSDate(), free: nil, club: nil, eventText: nil)