如何摆脱RxSwift中Variable的初始值

Question

I have been working on RxSwift, I am using a Variable in RxSwift which is hooked(bind to) to UICollectionView . Now knowing that Variable extends from Behavior Subjects I had to create a Variable with some dummy initial value.

 var myArray = Variable<[MyDataModel]>([MyDataModel(data: "{:}")])

MyDataModel is a struct that takes json as a init parameter.(As MyModel has nothing to with the question that follows am not posting the structure of it here)

Now, when I hook it to collectionView, I know that I should ignore the first signal emitted so I use skip(1)

myArray.asObservable().skip(1).bind(to: collectionView.rx.items(cellIdentifier: "test", cellType: MyCollectionViewCell.self){
        //cell implementation    
})

Though above code works, it solves the problem partially. Though the first change in the value of myArray is ignored, but when I append the actually data to myArray later using

myArray.value.append(someNewData)

it emits the notification and unfortunately this time myArray.value has two values (dummy one I added while initializing and one that actually triggered onNext )

So as a work around, what I do is before blindly appending data to myArray.value I check if it has dummy object I added, if yes I remove it and add the actual object.

Though work around works, makes my code looks very ugly and non Rx in a way. I believe there must be a proper way to deal with it as it is a very fundamental problem working with Variable .

I would really appreciate your thoughts on the same.

Answer 1

First of all, Variable is deprecated in RxSwift 4.x in favor of BehaviorRelay .

But for your purpose, PublishSubject or BehaviorSubject (if you need to cache the latest value) should suffice.