Method CreateDataChannel

peerconnection.go:2380–2460

CreateDataChannel creates a new DataChannel object with the given label and optional DataChannelInit used to configure properties of the underlying channel such as data reliability. nolint:cyclop

(label string, options *DataChannelInit)

//
//nolint:cyclop
func (pc *PeerConnection) CreateDataChannel(label string, options *DataChannelInit) (*DataChannel, error) {
	// https://w3c.github.io/webrtc-pc/#peer-to-peer-data-api (Step #2)
	if pc.isClosed.Load() {
		return nil, &rtcerr.InvalidStateError{Err: ErrConnectionClosed}
	}

	params := &DataChannelParameters{
		Label:   label,
		Ordered: true,
	}

	// https://w3c.github.io/webrtc-pc/#peer-to-peer-data-api (Step #19)
	if options != nil {
		params.ID = options.ID
	}

	if options != nil { //nolint:nestif
		// Ordered indicates if data is allowed to be delivered out of order. The
		// default value of true, guarantees that data will be delivered in order.
		// https://w3c.github.io/webrtc-pc/#peer-to-peer-data-api (Step #9)
		if options.Ordered != nil {
			params.Ordered = *options.Ordered
		}

		// https://w3c.github.io/webrtc-pc/#peer-to-peer-data-api (Step #7)
		if options.MaxPacketLifeTime != nil {
			params.MaxPacketLifeTime = options.MaxPacketLifeTime
		}

		// https://w3c.github.io/webrtc-pc/#peer-to-peer-data-api (Step #8)
		if options.MaxRetransmits != nil {
			params.MaxRetransmits = options.MaxRetransmits
		}

		// https://w3c.github.io/webrtc-pc/#peer-to-peer-data-api (Step #10)
		if options.Protocol != nil {
			params.Protocol = *options.Protocol
		}

		// https://w3c.github.io/webrtc-pc/#peer-to-peer-data-api (Step #11)
		if len(params.Protocol) > 65535 {
			return nil, &rtcerr.TypeError{Err: ErrProtocolTooLarge}
		}

		// https://w3c.github.io/webrtc-pc/#peer-to-peer-data-api (Step #12)
		if options.Negotiated != nil {
			params.Negotiated = *options.Negotiated
		}
	}

	dataChannel, err := pc.api.newDataChannel(params, nil, pc.log)
	if err != nil {
		return nil, err
	}

	// https://w3c.github.io/webrtc-pc/#peer-to-peer-data-api (Step #16)
	if dataChannel.maxPacketLifeTime != nil && dataChannel.maxRetransmits != nil {
		return nil, &rtcerr.TypeError{Err: ErrRetransmitsOrPacketLifeTime}