在init中的闭包内快速调用self

Question

convenience init(title: String!,
    datePickerMode: UIDatePickerMode,
    selectedDate: Date!,
    origin view: UIView!) {

        self.init(title: title,
                  datePickerMode: datePickerMode,
                  selectedDate: selectedDate,
                  doneBlock: { [weak self] (_, date , _) in
                                guard let sself = self else { return }
                                sself.done.next(date as! Date)
                    }
            ,
            cancel: { [weak self] (_) in
                                guard let sself = self else { return }
                                sself.cancel.next()
                    }
            ,
            origin: view)

But I get compiler error:

'self' used before self.init call

I worked it around, with first initializing with closure nil and setting right after.

convenience init(title: String!,
                 datePickerMode: UIDatePickerMode,
                 selectedDate: Date!,
                 origin view: UIView!) {

    self.init(title: title,
              datePickerMode: datePickerMode,
              selectedDate: selectedDate,
              doneBlock: nil,
              cancel: nil,
              origin: view)


    self.onActionSheetDone = { [weak self] (_, date , _) in
        guard let sself = self else { return }
        sself.done.next(date as! Date)
    }


    self.onActionSheetCancel = { [weak self] (_) in
        guard let sself = self else { return }
        sself.cancel.next()
    }

But I don't understand what the problem in doing it in first way. Thanks for providing some information

Answer 1

In first condition, you used self before self had init in the closure. This is not allowed.