PowerBuilder

WebSocket Connect through HTTP Proxy

See more WebSocket Examples

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

integer li_rc
integer li_Success
oleobject loo_Rest
oleobject loo_Socket
integer li_BTls
integer li_Port
integer li_MaxWaitMs
oleobject loo_Ws
string ls_ResponseBody
integer li_StatusCode

li_Success = 0

// 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.  
// 

loo_Rest = create oleobject
li_rc = loo_Rest.ConnectToNewObject("Chilkat.Rest")
if li_rc < 0 then
    destroy loo_Rest
    MessageBox("Error","Connecting to COM object failed")
    return
end if
loo_Socket = create oleobject
li_rc = loo_Socket.ConnectToNewObject("Chilkat.Socket")

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

// Provide authentication to the HTTP proxy, if needed.
loo_Socket.HttpProxyUsername = "HTTP_PROXY_LOGIN"
loo_Socket.HttpProxyPassword = "HTTP_PROXY_PASSWORD"
loo_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.
loo_Socket.HttpProxyForHttp = 1

// Connect to the websocket server through the HTTP proxy.
li_BTls = 0
li_Port = 80
li_MaxWaitMs = 5000
li_Success = loo_Socket.Connect("some-websocket-server.com",li_Port,li_BTls,li_MaxWaitMs)
if li_Success <> 1 then
    Write-Debug "Connect Failure Error Code: " + string(loo_Socket.ConnectFailReason)
    Write-Debug loo_Socket.LastErrorText
    destroy loo_Rest
    destroy loo_Socket
    return
end if

// Tell the Rest object to use the connected socket.
li_Success = loo_Rest.UseConnection(loo_Socket,1)
if li_Success <> 1 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Rest
    destroy loo_Socket
    return
end if

loo_Ws = create oleobject
li_rc = loo_Ws.ConnectToNewObject("Chilkat.WebSocket")

// Tell the WebSocket to use this connection.
li_Success = loo_Ws.UseConnection(loo_Rest)
if li_Success <> 1 then
    Write-Debug loo_Ws.LastErrorText
    destroy loo_Rest
    destroy loo_Socket
    destroy loo_Ws
    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.)
loo_Ws.AddClientHeaders()

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

// Do the open handshake.
ls_ResponseBody = loo_Rest.FullRequestNoBody("GET","/something")
if loo_Rest.LastMethodSuccess <> 1 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Rest
    destroy loo_Socket
    destroy loo_Ws
    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..)
li_StatusCode = loo_Rest.ResponseStatusCode
Write-Debug "Response status code: " + string(li_StatusCode)

if li_StatusCode <> 101 then
    Write-Debug ls_ResponseBody
    Write-Debug "-- Failed because of unexpected response status code."
    destroy loo_Rest
    destroy loo_Socket
    destroy loo_Ws
    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. 
li_Success = loo_Ws.ValidateServerHandshake()
if li_Success <> 1 then
    Write-Debug loo_Ws.LastErrorText
    destroy loo_Rest
    destroy loo_Socket
    destroy loo_Ws
    return
end if

Write-Debug "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...)

Write-Debug "Success."


destroy loo_Rest
destroy loo_Socket
destroy loo_Ws