Visual Basic 6.0

Read Bitfinex WebSocket Ticker Channel

See more WebSocket Examples

Subscribes to the public Bitfinex websocket ticker channel and receives ticker updates. Visual Basic 6.0

Dim success As Long
success = 0

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

Dim ws As New ChilkatWebSocket

' 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 ChilkatRest

' Connect to api.bitfinex.com
success = rest.Connect("api.bitfinex.com",443,1,0)
success = ws.UseConnection(rest)
success = ws.AddClientHeaders()

Dim responseBody As String
responseBody = rest.FullRequestNoBody("GET","/ws")
success = ws.ValidateServerHandshake()
If (success <> 1) Then
    Debug.Print ws.LastErrorText
    Debug.Print responseBody
    Debug.Print rest.ResponseHeader
    Exit Sub
End If

' After connecting, the bitfinex websocket server will send
' an info message that contains the actual version of the websocket stream.
' Receive that message..
success = ws.ReadFrame()
If (success <> 1) Then
    Debug.Print "Failed to receive a frame"
    Debug.Print "ReadFrame fail reason = " & ws.ReadFrameFailReason
    Debug.Print ws.LastErrorText
    Exit Sub
End If

' We should get this:
' {"event":"info","version":1.1,"platform":{"status":1}}
Debug.Print ws.GetFrameData()

' Subscribe to the public ticker feed.
' See https://docs.bitfinex.com/docs for more information.
Dim json As New ChilkatJsonObject
success = json.AppendString("event","subscribe")
success = json.AppendString("channel","ticker")
success = json.AppendString("pair","BTCUSD")

Dim finalFrame As Long
finalFrame = 1
success = ws.SendFrame(json.Emit(),finalFrame)

' Read the response.
success = ws.ReadFrame()
If (success <> 1) Then
    Debug.Print "Failed to receive a frame"
    Debug.Print "ReadFrame fail reason = " & ws.ReadFrameFailReason
    Debug.Print ws.LastErrorText
    Exit Sub
End If

' Examine the response
' We should get this:
' {"event":"subscribed","channel":"ticker","chanId":2751,"pair":"BTCUSD"}
Debug.Print ws.GetFrameData()

' Begin reading the ticker feed.
' We'll just read the 1st 5 updates and then exit..
Dim receivedFinalFrame As Long
receivedFinalFrame = 0
Dim numUpdatesReceived As Long
numUpdatesReceived = 0
Do While numUpdatesReceived < 5

    success = ws.ReadFrame()
    If (success <> 1) Then
        Debug.Print "Failed to receive a frame"
        Debug.Print "ReadFrame fail reason = " & ws.ReadFrameFailReason
        Debug.Print ws.LastErrorText
        Exit Sub
    End If

    ' The responses we desire are in Text frames, where the opcode = 1.
    If (ws.FrameOpcodeInt = 1) Then
        Dim receivedText As String
        receivedText = ws.GetFrameData()
        Debug.Print receivedText
        ' Should receive a line of text such as this:
        ' [2751,7349,36.34269559,7349.1,41.01777063,-116.2,-0.0156,7349.1,22188.26055319,7560,7270.5]
        numUpdatesReceived = numUpdatesReceived + 1
    End If

Loop

' Close the websocket connection.
success = ws.SendClose(1,1000,"Closing this websocket.")
If (success <> 1) Then
    Debug.Print ws.LastErrorText
    Exit Sub
End If

' Read the Close response.
success = ws.ReadFrame()
If (success <> 1) Then
    Debug.Print "ReadFrame fail reason = " & ws.ReadFrameFailReason
    Debug.Print ws.LastErrorText
    Exit Sub
End If

Debug.Print "Success."