(MFC) WebSocket Connect

Demonstrates how to establish a WebSocket connection. Once the connection is established, messages may be sent back-and-forth. Messages are sent in frames, where the last frame in the message is indicated by a "final" bit. A frame constitutes the entire message if the first frame sent has the "final" bit sent. (In most cases, you'll probably be sending single-frame messages.)

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkRest.h>
#include <CkWebSocket.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    //  --------------------------------------------------
    //  A WebSocket connection begins life as an HTTP GET request containing a few special header fields,
    //  such as "Upgrade: websocket".

    //  Your application will use the Chilkat Rest class to send the initial HTTP GET.  This allows you
    //  to use the full capability of the Chilkat Rest class to customize the GET for any particular situation.
    //  For example:
    // 
    //    - If custom HTTP request header fields must be added.
    //    - If authentication is required, such as OAuth2, OAuth1, Basic HTTP Auth, etc.
    //    - If HTTPS, SSH Tunneling, Proxies (HTTP or SOCKS), or other advanced connection or TLS features are required.
    // 

    CkRest rest;
    bool success = rest.Connect("someserver.com",80,false,false);
    if (success != true) {
        strOut.append(rest.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkWebSocket ws;

    //  Tell the WebSocket to use this connection.
    success = ws.UseConnection(rest);
    if (success != true) {
        strOut.append(ws.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

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

    //  Add any additional headers that might be desired.
    //  Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
    rest.AddHeader("Sec-WebSocket-Protocol","x-something");
    rest.AddHeader("Origin","http://someserver.com");

    //  Do the open handshake.
    const char *responseBody = rest.fullRequestNoBody("GET","/something");
    if (rest.get_LastMethodSuccess() != true) {
        strOut.append(rest.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  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..)
    int statusCode = rest.get_ResponseStatusCode();
    strOut.append("Response status code: ");
    strOut.appendInt(statusCode);
    strOut.append("\r\n");

    if (statusCode != 101) {
        strOut.append(responseBody);
        strOut.append("\r\n");
        strOut.append("-- Failed because of unexpected response status code.");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  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) {
        strOut.append(ws.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    strOut.append("WebSocket connection successful.");
    strOut.append("\r\n");

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


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }