Is Network.framework recommended atm?

I also read that some people have issues submitting Apps that use Network framework?

There were problems submitting Swift code that uses the Network framework (see this thread) but my understanding is that they’ve been resolved.

I find there is low level documentation missing especiall when using swift.

Indeed. The documentation is definitely lagging behind the framework implementation. Then again, that’s true for most of the technologies I work on )-:

So is Network.framework ready for use?

Yes.

As to whether you should use it, that really depends on your specific requirements. If you’re writing new code that needs to deal with TCP or UDP, with or without TLS, and you’re OK with the iOS 12 deployment target, I think it’s a fine option. It’s certainly much nicer than the alternatives.

If you have specific questions I’d be happy to tackle them here. For example, you wrote:

I have trouble finding out when the server end of a socket was closed. The

connectionStateUpdateHandler

does not seem to get any notification?

This is working for me. Do you have an outstanding read pending on the connection? An EOF is indicated by a read with

isComplete

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

;-)

Something about Network.framework I do not understand though:

I am using Network.framework via tcp to connect to a device which exposes a wifi network. Since I want to play nice I accept that the app disconnects the network when it is backgrounded and implemented a reconnect. So when my app gets back from background and gets active I create a new nwnetworkconnection. All works great. Except...

The problem I am facing is that sometimes my connection remains in .waiting and I don't know why.

I rely on a Wifi connection in the background. if the Wifi connection got lost during background, too, I try to establish the Wifi connection with NENetworkConnectionManager:

NEHotspotConfigurationManager.shared.apply(config, completionHandler: closure )

In the closure I reconnect my nwnetwork connection by establishing a new connection:

self.connection = connection

nwconnection = NWConnection(host: NWEndpoint.Host(addr), port: NWEndpoint.Port(integerLiteral: NWEndpoint.Port.IntegerLiteralType(CapPort)), using: .tcp)

nwconnection.stateUpdateHandler = { [weak self](newState) in

guard let self = self else { return }

guard let connection = self.connection else { return }

switch (newState) {

case .ready:

print_debug("NWHandler: Connection Ready!", level:10)

connection.capConnectionState = CAPConnectionState.expectingWelcome

self.readHeader()

case .waiting(_):

print_debug("NWHandler: Connection Waiting!", level:10)

connection.capConnectionState = CAPConnectionState.waiting

case .failed(_):

print_debug("NWHandler: Connection Failed!", level:10)

connection.capConnectionState = CAPConnectionState.networkError

default:

break

}

}

//Start the connection

nwconnection.start(queue: nwqueue)

What happens sometimes is that the connection remains in the .waiting stage and never connects or fails. I suspect this has to do with the Wifi network not being completly established (even though I am calling it in the completion of NEHotspotConfigurationManager.shared.apply.

I assumed that connectivity issues are supposed to be taken care of by Network.framework and that eventually when the host is reachable the connection would progress to connected or at least fail (so I could try again)? Problem is that on a higher level I cannot really deal with .waiting very well...

Everything works fine if Wifi is preconnected and I have a properly set-up network.

Do I expect the wrong thing and I need to test for reachability of the host before I start the connection? Or are there DispatchQueue issues? (i specify my network queue to handle the connection).

I am a bit lost with this one.

Thanks for your help!

Michael

EDIT: Seems like the reachability logic of Network.framework is linked to DNS is some way? I previously used the std. IP Address of the device and got stuck. Now I have Bonjour working and it works.