C

WebSocket Connect

See more WebSocket Examples

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.) C

#include <C_CkRest.h>
#include <C_CkWebSocket.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkRest rest;
    HCkWebSocket ws;
    const char *responseBody;
    int statusCode;

    success = FALSE;

    // 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.
    // 

    rest = CkRest_Create();
    success = CkRest_Connect(rest,"someserver.com",80,FALSE,FALSE);
    if (success != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        return;
    }

    ws = CkWebSocket_Create();

    // Tell the WebSocket to use this connection.
    success = CkWebSocket_UseConnection(ws,rest);
    if (success != TRUE) {
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkRest_Dispose(rest);
        CkWebSocket_Dispose(ws);
        return;
    }

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

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

    // Do the open handshake.
    responseBody = CkRest_fullRequestNoBody(rest,"GET","/something");
    if (CkRest_getLastMethodSuccess(rest) != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        CkWebSocket_Dispose(ws);
        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..)
    statusCode = CkRest_getResponseStatusCode(rest);
    printf("Response status code: %d\n",statusCode);

    if (statusCode != 101) {
        printf("%s\n",responseBody);
        printf("-- Failed because of unexpected response status code.\n");
        CkRest_Dispose(rest);
        CkWebSocket_Dispose(ws);
        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 = CkWebSocket_ValidateServerHandshake(ws);
    if (success != TRUE) {
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkRest_Dispose(rest);
        CkWebSocket_Dispose(ws);
        return;
    }

    printf("WebSocket connection successful.\n");

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


    CkRest_Dispose(rest);
    CkWebSocket_Dispose(ws);

    }