(C) Subscribe to Multiple Bitfinex Tickers on One Connection

Subscribes to multiple ticker symbols on the public Bitfinex websocket ticker channel and receives ticker updates.

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

void ChilkatSample(void)
    {
    HCkWebSocket ws;
    HCkRest rest;
    BOOL success;
    const char *responseBody;
    HCkJsonObject json1;
    BOOL finalFrame;
    HCkJsonObject json2;
    BOOL receivedFinalFrame;
    int numUpdatesReceived;
    const char *receivedText;

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

    ws = CkWebSocket_Create();

    // 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.

    rest = CkRest_Create();

    // Connect to api.bitfinex.com
    success = CkRest_Connect(rest,"api.bitfinex.com",443,TRUE,FALSE);
    CkWebSocket_UseConnection(ws,rest);
    CkWebSocket_AddClientHeaders(ws);

    responseBody = CkRest_fullRequestNoBody(rest,"GET","/ws");
    success = CkWebSocket_ValidateServerHandshake(ws);
    if (success != TRUE) {
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        printf("%s\n",responseBody);
        printf("%s\n",CkRest_responseHeader(rest));
        CkWebSocket_Dispose(ws);
        CkRest_Dispose(rest);
        return;
    }

    // After connecting, the bitfinex websocket server will send
    // an info message that contains the actual version of the websocket stream.
    // Receive that message..
    success = CkWebSocket_ReadFrame(ws);
    if (success != TRUE) {
        printf("Failed to receive a frame\n");
        printf("ReadFrame fail reason = %d\n",CkWebSocket_getReadFrameFailReason(ws));
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkWebSocket_Dispose(ws);
        CkRest_Dispose(rest);
        return;
    }

    // We should get this:
    // {"event":"info","version":1.1,"platform":{"status":1}}
    printf("%s\n",CkWebSocket_getFrameData(ws));

    // Subscribe to the BTCUSD ticker feed.
    // See https://docs.bitfinex.com/docs for more information.
    json1 = CkJsonObject_Create();
    CkJsonObject_AppendString(json1,"event","subscribe");
    CkJsonObject_AppendString(json1,"channel","ticker");
    CkJsonObject_AppendString(json1,"pair","BTCUSD");

    finalFrame = TRUE;
    success = CkWebSocket_SendFrame(ws,CkJsonObject_emit(json1),finalFrame);

    // Subscribe to the ETHUSD ticker feed.
    json2 = CkJsonObject_Create();
    CkJsonObject_AppendString(json2,"event","subscribe");
    CkJsonObject_AppendString(json2,"channel","ticker");
    CkJsonObject_AppendString(json2,"pair","ETHUSD");

    success = CkWebSocket_SendFrame(ws,CkJsonObject_emit(json2),finalFrame);

    // Begin reading the ticker feed.
    // / This will include a single confirmation response for each subscription.

    // We'll just read the 1st 5 updates and then exit..
    receivedFinalFrame = FALSE;
    numUpdatesReceived = 0;
    while (numUpdatesReceived < 7) {

        success = CkWebSocket_ReadFrame(ws);
        if (success != TRUE) {
            printf("Failed to receive a frame\n");
            printf("ReadFrame fail reason = %d\n",CkWebSocket_getReadFrameFailReason(ws));
            printf("%s\n",CkWebSocket_lastErrorText(ws));
            CkWebSocket_Dispose(ws);
            CkRest_Dispose(rest);
            CkJsonObject_Dispose(json1);
            CkJsonObject_Dispose(json2);
            return;
        }

        // The responses we desire are in Text frames, where the opcode = 1.
        if (CkWebSocket_getFrameOpcodeInt(ws) == 1) {
            receivedText = CkWebSocket_getFrameData(ws);
            printf("%s\n",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]
            // Initially, a single confirmation response for each subscription would be received, such as this:
            // {"event":"subscribed","channel":"ticker","chanId":810,"pair":"BTCUSD"}
            numUpdatesReceived = numUpdatesReceived + 1;
        }

    }

    // This is sample output:
    // You can see that the 1st message received is the subscription confirmation for the BTCUSD subscribe request.
    // The next message is a BTCUSD ticker update.
    // The next message is the confirmation for the ETHUSD subscription.
    // The next message is an ETHUSD update.
    // The BTCUSD channel ID is "537", and the ETHUSD channel ID is "700".  The channel IDs are provided in the 
    // subscription confirmation messages.  Each ticker update begins with the channel ID..

    // {"event":"subscribed","channel":"ticker","chanId":537,"pair":"BTCUSD"}
    // [537,6457.9,79.59102302,6458,22.49395741,-24.1,-0.0037,6457.9,13644.52820029,6540,6370.76958739]
    // {"event":"subscribed","channel":"ticker","chanId":700,"pair":"ETHUSD"}
    // [700,496.9,247.24493326,496.92,284.09636979,-2.47,-0.0049,496.9,74154.05945261,502.85,486.96]
    // [537,"hb"]
    // [700,"hb"]
    // [700,496.92,233.34338276,496.93,431.78867277,-2.45,-0.0049,496.92,74167.99173586,502.85,486.96]

    // Close the websocket connection.
    success = CkWebSocket_SendClose(ws,TRUE,1000,"Closing this websocket.");
    if (success != TRUE) {
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkWebSocket_Dispose(ws);
        CkRest_Dispose(rest);
        CkJsonObject_Dispose(json1);
        CkJsonObject_Dispose(json2);
        return;
    }

    // Read the Close response.
    success = CkWebSocket_ReadFrame(ws);
    if (success != TRUE) {
        printf("ReadFrame fail reason = %d\n",CkWebSocket_getReadFrameFailReason(ws));
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkWebSocket_Dispose(ws);
        CkRest_Dispose(rest);
        CkJsonObject_Dispose(json1);
        CkJsonObject_Dispose(json2);
        return;
    }

    printf("Success.\n");


    CkWebSocket_Dispose(ws);
    CkRest_Dispose(rest);
    CkJsonObject_Dispose(json1);
    CkJsonObject_Dispose(json2);

    }