Web socket handlers

You can automatically upgrade http requests to web sockets with frz.ServerWithWebSocketHandler().

frz.ServerWithWebSocketHandler(server, "GET /", 
    func(request *frz.Request, response *frz.Response) {
        for {
            frz.SendEcho(response, "hello")
            message := frz.ReceiveMessage(request)
            fmt.Printf("Received message `%s`.\n", message)
        }
    },
)

Note

Web socket patterns must always use the GET verb.

Note

Returning from the callback function will automatically close the web socket connection.
In the example above, exiting the for loop will automatically close the web socket connection.

All web socket handlers are compatible with many of the same functions used by traditional request handlers.

However, many other functions that send data to the client have little compatibility with web sockets because of the nature of the protocol itself.

Note

For example, you won't be able to send a status code to the client in your websocket loop because because by the time your callback function is executed, the underlying web socket handshake has already terminated and the status code has already been sent.

The following is a compatibility table between web socket and request handlers.

Function	Compatible with request handlers	Compatible with web socket handlers
ReceivePath	Yes	Yes
ReceiveQuery	Yes	Yes
ReceiveHeader	Yes	Yes
ReceiveContentType	Yes	Yes
ReceiveMessage	Yes	Yes
ReceiveJson	Yes	Yes
ReceiveForm	Yes	No
VerifyContentType	Yes	Yes
SendRedirect	Yes	No
SendRedirectToSecure	Yes	No
SendStatus	Yes	No
SendHeader	Yes	No
SendContent	Yes	Yes
SendEcho	Yes	Yes
SendEmbeddedFileOrIndexOrElse	Yes	No
SendEmbeddedFileOrElse	Yes	No
SendFileOrIndexOrElse	Yes	No
SendFileOrElse	Yes	No
SendWebSocketUpgrade	Yes	No
SendSveltePage	Yes	No