Xojo Plugin

WebSocket Connect through HTTP Proxy

See more WebSocket Examples

This example shows how to establish a WebSocket connection through an HTTP proxy server. Xojo Plugin

Dim success As Boolean
success = False

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

// --------------------------------------------------
// This example borrows the code from the REST using HTTP Proxy example.
// We first use the Chilkat Socket object to establish a connection to the WebSocket server through an HTTP proxy.
// Next, the Rest object uses the Socket object for its connection.
// Finally, the WebSocket object uses the Rest object for its connection.  
// 

Dim rest As New Chilkat.Rest
Dim socket As New Chilkat.Socket

// Set the HTTP proxy domain or IP address, and port.
socket.HttpProxyHostname = "192.168.1.79"
socket.HttpProxyPort = 808

// Provide authentication to the HTTP proxy, if needed.
socket.HttpProxyUsername = "HTTP_PROXY_LOGIN"
socket.HttpProxyPassword = "HTTP_PROXY_PASSWORD"
socket.HttpProxyAuthMethod = "Basic"

// Indicate that HTTP requests (i.e. the WebSocket opening handshake) will be sent over the socket.
// This is important for how the HTTP proxy connection is established.
socket.HttpProxyForHttp = True

// Connect to the websocket server through the HTTP proxy.
Dim bTls As Boolean
bTls = False
Dim port As Int32
port = 80
Dim maxWaitMs As Int32
maxWaitMs = 5000
success = socket.Connect("some-websocket-server.com",port,bTls,maxWaitMs)
If (success <> True) Then
    System.DebugLog("Connect Failure Error Code: " + Str(socket.ConnectFailReason))
    System.DebugLog(socket.LastErrorText)
    Return
End If

// Tell the Rest object to use the connected socket.
success = rest.UseConnection(socket,True)
If (success <> True) Then
    System.DebugLog(rest.LastErrorText)
    Return
End If

Dim ws As New Chilkat.WebSocket

// Tell the WebSocket to use this connection.
success = ws.UseConnection(rest)
If (success <> True) Then
    System.DebugLog(ws.LastErrorText)
    Return
End If

// Add the standard WebSocket open handshake headers that will be needed.
// (This adds the required HTTP request headers to the rest object.)
success = ws.AddClientHeaders()

// Add any additional headers that might be desired.
// Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
success = rest.AddHeader("Sec-WebSocket-Protocol","x-some-websocket-subprotocol")
success = rest.AddHeader("Origin","http://some-websocket-server.com")

// Do the open handshake.
Dim responseBody As String
responseBody = rest.FullRequestNoBody("GET","/something")
If (rest.LastMethodSuccess <> True) Then
    System.DebugLog(rest.LastErrorText)
    Return
End If

// If successful, the HTTP response status code should be 101,
// and the response body will be empty. (If it failed, we'll have a look
// at the response body..)
Dim statusCode As Int32
statusCode = rest.ResponseStatusCode
System.DebugLog("Response status code: " + Str(statusCode))

If (statusCode <> 101) Then
    System.DebugLog(responseBody)
    System.DebugLog("-- Failed because of unexpected response status code.")
    Return
End If

// We have the expected 101 response, so let's now validate the 
// contents of the response, such as the value sent by the server in the
// Sec-WebSocket-Accept header. 
success = ws.ValidateServerHandshake()
If (success <> True) Then
    System.DebugLog(ws.LastErrorText)
    Return
End If

System.DebugLog("WebSocket connection successful.")

// The application may now begin sending and receiving frames on the WebSocket connection.
// (At this point, we're done with the rest and socket objects...)

System.DebugLog("Success.")