Establish callback in Swift for PubNub 4.0 to receive messages

Question

It appears to me that the documentation PubNub has for getting started in Swift don't apply to versions earlier than PubNub 4.0. I can't successfully establish a callback to register with PubNub.

My code:

class Communicator: NSObject, PNObjectEventListener {

    var pubNubClient: PubNub

    override init(){
        let config = PNConfiguration(
            publishKey: "my_publish_key",
            subscribeKey: "my_subscribe_key"
        )
        pubNubClient = PubNub.clientWithConfiguration(config);
        super.init()
        pubNubClient.addListener(self)
        pubNubClient.subscribeToChannels(["my_channel"], withPresence: false)
    }

    func didReceiveMessage(client: PubNub!, message: PNMessageResult!){
        /* THIS METHOD NEVER GETS REACHED */
    }
}

Digging into the PubNub source a bit, this is the area that seems to be having problems:

- (void)addListener:(id <PNObjectEventListener>)listener {

    dispatch_async(self.resourceAccessQueue, ^{

        if ([listener respondsToSelector:@selector(client:didReceiveMessage:)]) {
            /* this block is never reached!!! */
            [self.messageListeners addObject:listener];
        }

    /* Remaining Lines Stripped Away */
    });
}

I'm still relatively new to Swift and integrating with Objective C. I'm curious if there's a problem with the respondsToSelector since the Objective C code is referencing Swift code.

The messages are definitely getting passed; there's another lower level function in the PubNub library that's logging all the messages received.

Any help would be much appreciated.

score 4 · Answer 1 · answered Jul 06 '15 at 22:29

Versions prior to 4.0 are deprecated and wont work exactly how they used to.

I would recommend migrating over to the newest (4.0) SDK entirely, the new iOS SDK has removed a lot of bloat and compiles much faster. To get started view this tutorial.

To summarize, instantiating a PubNub client look as follows:

let config = PNConfiguration( 
    publishKey: "Your_Pub_Key", 
    subscribeKey: "Your_Sub_Key")   
client = PubNub.clientWithConfiguration(config) 
client?.addListener(self) 
client?.subscribeToChannels(["Your_Channel"], withPresence: false)

And the new didReceiveMessage function looks as follows:

func client(client: PubNub!, didReceiveMessage message: PNMessageResult!, withStatus status: PNErrorStatus!) { 
     //Do Something like
     //println(message) 
}

score 3 · Answer 2 · answered Jul 06 '15 at 21:40

3

Resolved by adding:

func client(client: PubNub!, didReceiveMessage message: PNMessageResult!) {

}

answered Jul 06 '15 at 21:40

Scott Lobdell

527
1
4
11

Hi Scott this is good news, let us know if there is anything we may provide details with support@pubnub.com – Stephen Blum Jul 06 '15 at 22:33
Currently, I am able to access it only by , message.data => { message = "{}"; subscribedChannel = 123; timetoken = 14392105288780634; } – Nigilan Aug 10 '15 at 12:47
How will I access the 'message' inside it ? – Nigilan Aug 10 '15 at 12:47
It returns a PNMessageData format data, my data is stuffed inside it. Any pointers on how to access it ? – Nigilan Aug 10 '15 at 14:35
1

I did: let encodedMessage = message.data.valueForKey("message") as! NSDictionary – Scott Lobdell Aug 10 '15 at 23:18

score 0 · Answer 3 · answered Aug 20 '15 at 16:44

The documentation on how to parse the received PNMessageResult is scant. Here's how I handled it:

func client(client: PubNub!, didReceiveMessage message: PNMessageResult!) {

  let encodedMessage = message.data.valueForKey("message") as! NSDictionary
  let messageType    = encodedMessage["meta"]! as! String
  let messageString  = encodedMessage["data"]!["msg"]! as! String

  print("PubNub: [\(messageType)] \(messageString)") 
}

score 0 · Answer 4 · answered Jul 05 '17 at 11:36

0

add _ client works for me!

func client(_ client: PubNub, didReceiveMessage message: PNMessageResult) {
    print("Pubnub Message: \(message)")
}

answered Jul 05 '17 at 11:36

webmastx

683
1
8
30

Establish callback in Swift for PubNub 4.0 to receive messages

4 Answers4