Swift 3 - Got an empty NetService.addresses array after exploring bonjour

Question

I'm pretty new in Swift 3.

I want to get the ip of my NetServices which I explored with bonjour to show them to the user, not to connect with the device. So far I can search for devices with bonjour and get them listed in a listView with this great access code:

https://github.com/ecnepsnai/BonjourSwift

This is my function to scan the bonjour services and put them into a local array of NetServices:

    // scanning for services, delete old bonjourServices Array and fill it with new discovered services

var bonjourServices = [NetService]()

private func putServicesToArray(){
    let browser: Bonjour = Bonjour()

    _ = browser.findService(Bonjour.Services.Line_Printer_Daemon, domain: Bonjour.LocalDomain) { (services) in

        self.bonjourServices.removeAll()


        for service in browser.services {

            if !(self.bonjourServices.contains(service)) {

                self.bonjourServices.append(service)
            }
        }
    }
}

I'm using this method to get the ip address, from Swift 3 how to resolve NetService IP?

 func netServiceDidResolveAddress(_ sender: NetService) {

    print("netServiceDidResolveAddress get called with \(sender).")

    var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))

    guard let data = sender.addresses?.first else {
        print("guard let data failed")
        return
         }
    do {
        try data.withUnsafeBytes { (pointer:UnsafePointer<sockaddr>) -> Void in
            guard getnameinfo(pointer, socklen_t(data.count), &hostname, socklen_t(hostname.count), nil, 0, NI_NUMERICHOST) == 0 else {
                throw NSError(domain: "domain", code: 0, userInfo: ["error":"unable to get ip address"])
            }
        }
    } catch {
        print(error)
        return
    }
    let address = String(cString:hostname)
    print("Adress:", address)
}

And with this IBAction I just want to print the ip address, but my ip is empty and my bonjourServices[0].addresses is empty also the addresses.adress NSData Objects

    @IBAction func detectNetwork(_ sender: UIButton) {
    print("putServiceToArray: ")

    putServicesToArray()


    for service in bonjourServices {
        print(service)
    }

    bonjourTableView.reloadData()

    if !(bonjourServices.isEmpty){

        print(netServiceDidResolveAddress(bonjourServices[0]))
        print(bonjourServices[0].addresses)
    }

}

Here is my console output:

netServiceDidResolveAddress get called with <NSNetService 0x61800003d6a0> local. _printer._tcp. Brother HL-3152CDW series.
guard let data failed
()
Optional([])

Can you please help me resolve this problem?

Answer 1

I managed to solve my problem with this post: Bonjour Service Browser with Swift does not fetch serviceinfo

I did use Swift Development with Cocoa: Developing for the Mac and IOS App Stores published by O'Reilly for my code from page 299:

https://books.google.de/books?id=pNzSBQAAQBAJ&pg=PA299&lpg=PA299&dq=swift+implement+bonjour+discovery&source=bl&ots=6nhrmuDfEp&sig=eY9kPtzOl7nshavmwdwVYQlpNfM&hl=de&sa=X&ved=0ahUKEwjclvHGncLUAhXBKFAKHZeRByQ4ChDoAQgyMAI#v=onepage&q=swift%20implement%20bonjour%20discovery&f=false

And then I had to make a call like this:

    self.bonjourServices.removeAll()
    self.browser = NetServiceBrowser()
    self.browser.delegate = self
    self.browser.searchForServices(ofType:"_raop._tcp", inDomain: "")

Now it's working fine and I got all data of my services.