The implementation of the Transport interface for XHR polling
The connection URI
A flag indicating whether sending of poll requests has been aborted
The emitter used for emitting events
A flag indicating that the transport is currently sending requests
The connection options
A sequence number for ping requests
The last poll request
A sequence number for polling requests
The protocol version
The message queue
The session token that was received from the server at connection
The transport constructor function
Aborting any opening poll request.
This is the generic method to send data to the server
the headers to send to the server
the URI to connect to
Queue message to be sent to the message message-queue.
Delegate the actual request sending to #flush().
to be queued
Flush all pending messages from the message-queue and send upstream.
Send a poll request to the server.