Cannot assign to property: 'self' is immutable error

Question

private let selectedPhotos = BehaviorRelay<[PHAsset]>(value: [])

private lazy var completeButton = UIBarButtonItem(title: "확인",
                                                      style: .plain,
                                                      target: nil,
                                                      action: nil)

A variable is declared.

private func bind() {
        selectedPhotos.asObservable()
            .map { $0.isEmpty } 
            .bind(to: completeButton.rx.isHidden)
            .disposed(by: disposeBag)
    }

"Cannot assign to property: 'self' is immutable"
I got this error

"completeButton.rx.isHidden" is underlined.

These codes are written in class

```private let selectedPhotos = BehaviorRelay<[PHAsset]>(Value: [])``` it is declared like this — Hees, Aug 28 '23 at 07:55
```private lazy var completeButton = UIBarButtonItem(title: "확인", style: .plain, target: nil, action: nil)``` — Hees, Aug 28 '23 at 07:56
Can you [edit] your question to show more code. Presumably this function is in a struct? — Paulw11, Aug 28 '23 at 08:38
Additionally this error also occurs "Command SwiftCompile failed with a nonzero exit code" — Hees, Aug 28 '23 at 08:56
I fixed this issue with a clear build, but it often reoccurs. — Hees, Aug 28 '23 at 08:57
"Command SwiftCompile failed with a nonzero exit code" this error in my experience is often just Xcode being confused about why it failed but you can either delete the cash to get the right error or sometimes dig a bit more into the compilation log — La pieuvre, Aug 28 '23 at 09:05
I would really appreciate it if you could tell me the specific way — Hees, Aug 28 '23 at 09:08
In xCode : product / clean build folder. Also quit and relaunch XCode sometimes. — Ptit Xav, Aug 28 '23 at 12:00
Are you calling `bind` from within the `init` method? We *really* need to see more code. — Daniel T., Aug 28 '23 at 14:30

score -1 · Answer 1 · answered Aug 28 '23 at 13:47

-1

as you mentioned

private let selectedPhotos = BehaviorRelay<[PHAsset]>(Value: [])

is declared as a let constant.

Use var instead.

If it's declared inside a viewController (that is a class of course) this way it should become mutable.

answered Aug 28 '23 at 13:47

Foccoland

1

A BehaviorRelay is a class. You should never use `var` to define one because you don't want to loose all the observers. – Daniel T. Aug 28 '23 at 14:29

score -1 · Answer 2 · answered Aug 29 '23 at 23:50

-1

I solved it thanks to you. UIBarButtonItem supports isHidden from 16.0. But I am wondering why this error occurs

Originally, I know that this error occurs

answered Aug 29 '23 at 23:50

Hees

17
4

Cannot assign to property: 'self' is immutable error

2 Answers2