Replace the ws read interface with event callback.

[c98]

This is a feature pull request.

the key concept is that websocket use onMessageHandler instead of readStringMessage() or readBinaryMessage().

The problem which I occured is that I have to write the-read-logic(i.e. readStringMessage) in every sendStringMessage completion closure. The example is confusing(e.g. handleSession in the README.md), and in some complex case, this solution seems not good.

In this pull request, I moved the-read-logic into the websocket internal inspired by event-driven model. Here is the logic:

Now, we can use websocket simply, for example:

class AccessLayerHandler: WebSocketSessionHandler {
	// The name of the super-protocol we implement.
	// This is optional, but it should match whatever the client-side WebSocket is initialized with.
	let socketProtocol: String? = nil

	func handleSession(request: HTTPRequest, socket: WebSocket) {
		socket.onMessageHandler = {
			message, op, fin in
			guard let message = message else {
				socket.close()
				return
			}
			// TODO: handle the message
			// e.g. Echo this message back to client.
			socket.sendStringMessage(string: "echo", final: true) {}
		}
	}
}

That's it.

[kjessup]

Thank you for the PR. This change removes existing API and would cause breakage were it to be tagged under the current major version #. Is it possible to have both the older/existing API and the new method on top? Then nothing would break and the older functions can eventually be deprecated.

[c98]

@kjessup Thank you for your reply, and I think it over again.
imo, the existing API readStringMessage or readBinaryMessage conflicts with the new API onMessageHandler, unfortunately there is no way to keep both. :(

[saroar]

did you decide it will be marge in master branch?

[c98]

@saroar I will close this PR.