Publish `operationCount` from operationQueue inside actor?-CodePudding

I have an actor:

actor MyActor {
    
    let theQueue = OperationQueue()

    init() {

        _ = theQueue.observe(\OperationQueue.operationCount, options: .new) { oq, change in
            print("OperationQueue.operationCount changed: \(self.theQueue.operationCount)")
        }
        
    }

    ....

}

I was trying to get a KVO going to then trigger some type of publisher call that other models in the app could subscribe to and react as needed when the operationCount changes.

I was going to have a function that maybe would set that up, but, as of now, using self in that initializer gives me this warning, which according this this:

https://forums.swift.org/t/proposal-actor-initializers-and-deinitializers/52322

it will turn into an error soon.

The warning I get is this:

Actor 'self' can only be captured by a closure from an async initializer

So, how could I trigger a publisher other models can then react to that would publish the operation queue's operationCount as it changes?

CodePudding user response：

You don't need to capture self here. observe sends you the new value (for basically exactly this reason):

_ = theQueue.observe(\OperationQueue.operationCount, options: .new) { oq, change in
    print("OperationQueue.operationCount changed: \(change.newValue!)")
}

Also, oq is theQueue if you need that. If you need self, the typical way to do that is:

observation = observe(\.theQueue.operationCount, options: .new) { object, change in
    // object is `self` here.
}

Just remember that you're outside the actor inside this closure, so calls may need to be async inside a Task.