Ruby

WebSocket Send/Receive Binary Data

See more WebSocket Examples

Demonstrates how to send and receive binary data on a websocket. 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.

Ruby

require 'chilkat'

success = false

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

ws = Chilkat::CkWebSocket.new()

# 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.

rest = Chilkat::CkRest.new()
# 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.
success = rest.Connect("websockets.chilkat.io",80,false,false)
ws.UseConnection(rest)
ws.AddClientHeaders()
responseBodyIgnored = rest.fullRequestNoBody("GET","/wsChilkatEcho.ashx")
success = ws.ValidateServerHandshake()
if (success != true)
    print ws.lastErrorText() + "\n";
    exit
end

# This example sends a small JPG file (about 7KB) in a websocket frame.
jpgData = Chilkat::CkBinData.new()
success = jpgData.LoadFile("qa_data/jpg/starfish.jpg")

print "Number of bytes to send = " + jpgData.get_NumBytes().to_s() + "\n";

# Send a frame containing the JPG image data.
# This will be the first and final frame, and therefore this constitutes the entire message.
finalFrame = true
success = ws.SendFrameBd(jpgData,finalFrame)
if (success != true)
    print ws.lastErrorText() + "\n";
    exit
end

# Read the echoed binary frame(s).
# (We sent the JPG file in a single frame, but we may receive the echo in multiple frames, but it will be one message.)
# Read an incoming frames until we receive the final frame.
receivedFinalFrame = false
while receivedFinalFrame == false

    # The ws object is accumulating the received data internally.  Once we get the final frame, we'll get the 
    # accumulated data which should constitute the entire JPG.
    success = ws.ReadFrame()
    if (success != true)
        print "Failed to receive a frame" + "\n";
        print "ReadFrame fail reason = " + ws.get_ReadFrameFailReason().to_s() + "\n";
        print ws.lastErrorText() + "\n";
        exit
    end

    receivedFinalFrame = ws.get_FinalFrame()

    # Show the opcode and final frame bit for the frame just received:
    print "Frame opcode: " + ws.frameOpcode() + "\n";
    print "Final frame: " + receivedFinalFrame.to_s() + "\n";
end

# Get the accumulated received data.
jpgReceivedData = Chilkat::CkBinData.new()
ws.GetFrameDataBd(jpgReceivedData)
print "Received " + jpgReceivedData.get_NumBytes().to_s() + " bytes" + "\n";

# Save the received JPG to a file so we can check it..
jpgReceivedData.WriteFile("qa_output/starfish_ws.jpg")

# Close the websocket connection.
success = ws.SendClose(true,1000,"Closing this websocket.")
if (success != true)
    print ws.lastErrorText() + "\n";
    exit
end

# Read the Close response.
success = ws.ReadFrame()
if (success != true)
    print "ReadFrame fail reason = " + ws.get_ReadFrameFailReason().to_s() + "\n";
    print ws.lastErrorText() + "\n";
    exit
end

# Should receive the "Close" opcode.
print "Received opcode: " + ws.frameOpcode() + "\n";
# Should be the same status code we sent (1000)
print "Received close status code: " + ws.get_CloseStatusCode().to_s() + "\n";
# The server may echo the close reason.  If not, this will be empty.
print "Echoed close reason: " + ws.closeReason() + "\n";

print "Success." + "\n";