Xbase++

Send and Receive WebSocket Frame

See more WebSocket Examples

Demonstrates how to send a websocket text frame to a websocket echo server. This example uses Chilkat's websocket test echo server at ws://websockets.chilkat.io/wsChilkatEcho.ashx

Note: The websockets.chilkat.io server imposes the following limitations:
Messages must be 16K or less, and each connection is limited to a max of 16 echoed messages.

Xbase++

LOCAL nSuccess
LOCAL oWs
LOCAL oRest
LOCAL cResponseBodyIgnored
LOCAL nFinalFrame
LOCAL cReceivedStr

nSuccess := 0

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

oWs := CreateObject("Chilkat.WebSocket")

//  For brevity, this example does not check for errors when etablishing the WebSocket connection.
//  See Establish WebSocket Connection for more complete sample code for making the connection.

oRest := CreateObject("Chilkat.Rest")
//  Connect to websockets.chilkat.io
//  IMPORTANT: websockets.chilkat.io accepts frames of up to 16K in size and echoes them back.
//  IMPORTANT: The websockets.chilkat.io server imposes the following limitations: 
//  ---------- Messages must be 16K or less, and each connection is limited to a max of 16 echoed messages.
nSuccess := oRest:Connect("websockets.chilkat.io", 80, 0, 0)
oWs:UseConnection(oRest)
oWs:AddClientHeaders()
cResponseBodyIgnored := oRest:FullRequestNoBody("GET", "/wsChilkatEcho.ashx")
nSuccess := oWs:ValidateServerHandshake()
IF (nSuccess != 1)
    ? oWs:LastErrorText
    oWs:destroy()
    oRest:destroy()
    RETURN
ENDIF

//  This example demonstrates sending a frame and receiving a text frame.

//  Send a frame containing the string "Hello World!"
//  This will be the first and final frame, and therefore this constitutes the entire message.
nFinalFrame := 1
nSuccess := oWs:SendFrame("Hello World!", nFinalFrame)
IF (nSuccess != 1)
    ? oWs:LastErrorText
    oWs:destroy()
    oRest:destroy()
    RETURN
ENDIF

//  Read an incoming frame.
nSuccess := oWs:ReadFrame()
IF (nSuccess != 1)
    ? "Failed to receive a frame"
    ? "ReadFrame fail reason = " + Str(oWs:ReadFrameFailReason)
    ? oWs:LastErrorText
    oWs:destroy()
    oRest:destroy()
    RETURN
ENDIF

//  Show the string that was received.
cReceivedStr := oWs:GetFrameData()
? "Received: " + cReceivedStr

//  Close the websocket connection.
nSuccess := oWs:SendClose(1, 1000, "Closing this websocket.")
IF (nSuccess != 1)
    ? oWs:LastErrorText
    oWs:destroy()
    oRest:destroy()
    RETURN
ENDIF

//  Read the Close response.
nSuccess := oWs:ReadFrame()
IF (nSuccess != 1)
    ? "ReadFrame fail reason = " + Str(oWs:ReadFrameFailReason)
    ? oWs:LastErrorText
    oWs:destroy()
    oRest:destroy()
    RETURN
ENDIF

//  Should receive the "Close" opcode.
? "Received opcode: " + oWs:FrameOpcode
//  Should be the same status code we sent (1000)
? "Received close status code: " + Str(oWs:CloseStatusCode)
//  The server may echo the close reason.  If not, this will be empty.
? "Echoed close reason: " + oWs:CloseReason

? "Success."

oWs:destroy()
oRest:destroy()