Signaling server via firebase firestore

[oguzveozturk]

I'm trying to use Firestore for a signaling server, and I want to explain how I solved the problem i had:

When we click the Offer button, an SDP is created, but it does not contain any candidates. After 1-2 seconds, candidates are created and localDescription is updated without our knowledge. The problem is that we send already an SDP to the other user that does not contain candidates.

My not-so-smart solution:

        self.webRTCClient.offer { (_) in
            DispatchQueue.main.asyncAfter(deadline: .now()+1) { // maybe 2 seconds delay better
                self.webRTCClient.offer { (sdp) in
                       self.send(sdp: sdp)
                }
            }
        }

This problem also occurs when we click the Answer button. The initially created SDP does not contain any candidates. Therefore, we need to add a similar logic there as well:

        self.webRTCClient.answer { (_) in
            DispatchQueue.main.asyncAfter(deadline: .now()+1) {
                self.hasLocalSdp = true
                if let localSdp = self.webRTCClient.peerConnection.localDescription {
                    self.send(sdp: localSdp)
                }
            }
        }