SharedReader constructor

[jiledaa]

Hi all. In case I want to use just the synchronisation part of some state but dont want to write to it on certain level of hierarchy, I can use SharedReader, right? But when I have @SharedReader var name: String in state, I cannot just use SharedReader(name) or SharedReader("David") in preview or feature state init like I am able to do with Shared. I supposed both SharedReader and Shared are the same except SharedReader is not writable. Am I doing something wrong?

OK

@Shared var name: String
init(name: String) {
    _name = Shared(name)
}

nOK (Cannot convert value of type 'String' to expected argument type 'Shared')

@SharedReader var name: String
init(name: String) {
    _name = SharedReader(name)
}

[mbrandonw]

Hi @jiledaa, we do not expose that initializer on SharedReader because it doesn't seem to be very useful. A SharedReader(name) is just a constant that can never change, and so it might as well be a let name: String.

Is there a specific use case in mind you have for this?

[jiledaa]

Hi, so how is it done when parent has shared state and whenever I change it there, the child updates? But the child never changes the state in reducer, just listens for changes?

[mbrandonw]

In that case you need the parent to pass the child the Shared state, and then the child can turn it into a SharedReader:

@SharedReader var name: String
init(name: Shared<String>) {
    _name = SharedReader(name)
}

[jiledaa]

I see, thanks.