(Xojo Plugin) WebSocket Binance Trade Stream (subscribe and receive updates)

Subscribe to a binance trade stream and receive updates.

For more information, see https://binance-docs.github.io/apidocs/spot/en/#live-subscribing-unsubscribing-to-streams

Chilkat Xojo Plugin Download Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

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

Dim ws As New 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.

Dim rest As New Chilkat.Rest

// Connect to wss://stream.binance.com:9443
Dim success As Boolean
success = rest.Connect("stream.binance.com",9443,True,False)
If (success = False) Then
    System.DebugLog(rest.LastErrorText)
    Return
End If

success = ws.UseConnection(rest)
If (success = False) Then
    System.DebugLog(ws.LastErrorText)
    Return
End If

success = ws.AddClientHeaders()

//  Raw streams are accessed at /ws/<streamName>
Dim responseBody As String
responseBody = rest.FullRequestNoBody("GET","/ws/btcusdt")
If (rest.LastMethodSuccess = False) Then
    System.DebugLog(rest.LastErrorText)
    Return
End If

success = ws.ValidateServerHandshake()
If (success <> True) Then
    System.DebugLog(ws.LastErrorText)
    System.DebugLog(responseBody)
    System.DebugLog(rest.ResponseHeader)
    Return
End If

System.DebugLog(responseBody)
System.DebugLog(rest.ResponseHeader)

// POST JSON to subscribe to a stream

// {
// "method": "SUBSCRIBE",
// "params":
// [
// "btcusdt@aggTrade",
// "btcusdt@depth"
// ],
// "id": 1
// }

Dim json As New Chilkat.JsonObject
success = json.UpdateString("method","SUBSCRIBE")
success = json.UpdateString("params[0]","btcusdt@aggTrade")
success = json.UpdateString("params[1]","btcusdt@depth")
success = json.UpdateInt("id",1)

// Send a full message in a single frame
Dim finalFrame As Boolean
finalFrame = True
success = ws.SendFrame(json.Emit(),finalFrame)
If (success <> True) Then
    System.DebugLog(ws.LastErrorText)
    Return
End If

Dim jsonTradeData As New Chilkat.JsonObject
jsonTradeData.EmitCompact = False

// Begin reading the trade stream response.
// We'll just read the 1st 10 updates and then exit..
Dim receivedFinalFrame As Boolean
receivedFinalFrame = False
Dim numTradesReceived As Int32
numTradesReceived = 0
While numTradesReceived < 5

    success = ws.ReadFrame()
    If (success <> True) Then
        System.DebugLog("Failed to receive a frame")
        System.DebugLog("ReadFrame fail reason = " + Str(ws.ReadFrameFailReason))
        System.DebugLog(ws.LastErrorText)
        Return
    End If

    // The responses we desire are in Text frames, where the opcode = 1.
    If (ws.FrameOpcodeInt = 1) Then
        Dim receivedJson As String
        receivedJson = ws.GetFrameData()

        success = jsonTradeData.Load(receivedJson)
        System.DebugLog(jsonTradeData.Emit())

        numTradesReceived = numTradesReceived + 1
    End If

Wend

// Close the websocket connection.
success = ws.SendClose(True,1000,"Closing this websocket.")
If (success <> True) Then
    System.DebugLog(ws.LastErrorText)
    Return
End If

// Read the Close response.
success = ws.ReadFrame()
If (success <> True) Then
    System.DebugLog("ReadFrame fail reason = " + Str(ws.ReadFrameFailReason))
    System.DebugLog(ws.LastErrorText)
    Return
End If

System.DebugLog("Success.")

// The output of the above code is shown here: