BlocHolder

The BlocHolder is the iOS equivalent of getOrCreate() on Android:

• it creates a BlocContext with a lifecycle tied to the "lifecycle" of the BlocHolder object itself
• it calls a factory method with the BlocContext as parameter in order to create the Bloc
• it exposes the Bloc and the lifecycle as properties

Example:

struct CalculatorView: View {
    private let holder = BlocHolder { CalculatorKt.bloc(context: $0) }

tip

The lifecycle is tied to the lifecycle of the BlocHolder object itself. Unfortunately that means that you need to keep an explicit reference to that object like in the example above.

It's not good enough to create the BlocHolder and only keep a reference to the bloc and/or the lifecycle. The wrapper class (that is the BlocHolder) will be removed from memory eventually, even if the bloc is still in use. When that happens the bloc will be stopped/destroyed prematurely.

Experiments with tying the lifecycle to a View e.g. by using onAppear() / onDisappear(), didn't yield the expected results.