Known issue with CBCentralManager initialization

[pilmen]

@ #602 When try to init CBCentralManager with option CBCentralManagerOptionRestoreIdentifierKey (CBCentralManager(delegate: <CBCentralManagerDelegate?>, queue: <DispatchQueue?>, options: <[String : Any]?>)) you getting crash:
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '<CBCentralManager: 0x600002a73c40> has provided a restore identifier but the delegate doesn't implement the centralManager:willRestoreState: method'
I believe it happens because at the moment of initialization CBCentralManager calling delegate method centralManager:willRestoreState: if this key present. But we don't actually have delegate passed as a parameter at time of initialization. @tonyarnold @srdanrasic Do you have any suggestions how can I fix it? Thanks in advance.

[srdanrasic]

Hey @pilmen,

First of all, thank you for that PR. The reason I haven't merged it yet is because it would introduce dependency on CoreBluetooth which most Bond users don't use. I'm still looking into ways to resolve that.

To answer this question: Could you have a dummy delegate during the initialization that implements that method?

[srdanrasic]

You probably want something like this:

extension ReactiveExtensions where Base: NSObject {

    public static func makeWithProtocolProxy<P>(for `protocol`: Protocol, keyPath: ReferenceWritableKeyPath<Base, P?>, make: @escaping (P) -> Base) -> Base {
        let controller = OptionalKeyPathProtocolProxyPropertyController(object: nil, keyPath: keyPath)
        let protocolProxy = ProtocolProxy(protocol: `protocol`, propertyController: controller)
        let object = make(protocolProxy as! P)
        controller._object = object
        object.protocolProxies[controller] = protocolProxy
        return object
    }
}

so that you can do

let manager = CBCentralManager.reactive.makeWithProtocolProxy(for: CBCentralManagerDelegate.self, keyPath: \.delegate) { (delegate) -> CBCentralManager in
        return CBCentralManager(delegate: delegate, queue: nil, options: [:])
    }

Note that this will not work out of the box because KeyPathProtocolProxyPropertyController can't be initialized with nil object at the moment so you'll have to change that. If you want, please experiment, and if you get it working with a clean solution, do make a PR.

[pilmen]

Hey @pilmen,

First of all, thank you for that PR. The reason I haven't merged it yet is because it would introduce dependency on CoreBluetooth which most Bond users don't use. I'm still looking into ways to resolve that.

To answer this question: Could you have a dummy delegate during the initialization that implements that method?

Hey @srdanrasic , yes dummy delegate works in this case. I'll try to work with the approach from your last message. I'm not sure either if this extension should to be a part of main Bond Framework. Thanks for your help and great job around this framework.

[srdanrasic]

I will close this for now. Feel free to reopen if there will be more stuff on this.

[pilmen]

Sure, I didn't have much time to look into this. If I'll be have solution for this I let you know.