websocket: Create a websocket client.
In rstudio/R-Websockets: HTML 5 Websocket Interface for R

Description Usage Arguments Details Value Note Author(s) See Also Examples

Create a websocket client connection.

1	websocket(url, port=80, subprotocol="chat", version=0)

`url`	The websocket url to connect to.
`port`	The service port number.
`subprotocol`	A websocket subprotocol id.
`version`	A websocket protocol version.

Create a context for a websocket client connection. All the functions available to a websocket server context, including callbacks for handling events for the connection, may be defined just as with a server context created with create_server.

The websocket_write function can also be used to write data through the websocket client socket to the service.

An environment is returned. The service will search the environment for callback functions named: closed, established, and receive. The established and closed functions must take a single argument (a websocket). The receive function must take three arguments: DATA, WS, and HEADER, holding the message data, websocket client, and possible ancillary header information received.

The callback functions are optional. When a websocket event occurs, the corresponding function will be evaluated if it exists. The DATA parameter holds a raw vector with incoming data from broadcast or receive events, and may be of length zero for other events. The WS parameter is the client web socket corresponding to the event.

See the set_callback function for more information.

This package supports websocket protocol version numbers 0 and 8. Version 0 is the original draft websocket protocol specification. If your websocket service requires a different protocol version, it will probably also work since the newer protocols do not vary significantly in messaging details.

Once the websocket standard is set, this package will be updated to fully reflect the standardized version.

B. W. Lewis <blewis@illposed.net>

service, websocket_write set_callback

# Connect to the public websocket echo service
## Not run: 
client = websocket("ws://echo.websocket.org")
set_callback("receive", function(DATA, WS, HEADER) cat(rawToChar(DATA),"\n"), client)
websocket_write("Testing, testing", client)
service(client)
websocket_close(client)

## End(Not run)