C Programming Starter Kit 2.0/SamsPublishing-CProgrammingStarterKit-v2.0-Win31.iso/bde/snipit.pak/DBLOGIN.C

C/C++ Source or Header | 1997-07-24 | 5.5 KB | 165 lines

// BDE - (C) Copyright 1995 by Borland International

// Callback.C
#include "snipit.h"

static const DBIPATH szTblName      = "security";
static const char szTblType[]       = szDBASE;
pCHAR  CallBackData3;

CBRType DBIFN _export CallBackFunc3(CBType ecbType, UINT32 iClientData,
                                    pVOID pCbInfo);

//=====================================================================
//  Function:
//          LoginCallback();
//
//  Description:
//          This example shows how to access a dBASE table which is missing
//          it's .MDX file. This is accomplished with the use of the
//          cbINPUTREQ callback. Note that this method can also be used
//          to access FOX and CLIPPER tables.
//=====================================================================
void
LoginCallback (void)
{
    hDBIDb      hDb;                        // Handle to the database
    hDBICur     hCur;                       // Handle to the table
    UINT16      uNumOfRecs = 5;             // No. of records to display
    CBLoginDesc CbInfo;                     // Variable which is used within
                                            //   the callback
    DBIResult   rslt;                       // Return value from IDAPI
                                            //   functions

    Screen("*** Open Table CallBack Example ***\r\n");

    BREAK_IN_DEBUGGER();

    Screen("    Initializing IDAPI...");
    if (InitAndConnect(&hDb) != DBIERR_NONE)
    {
        Screen("*** End of Example ***");
        return;
    }

    Screen("    Setting the database directory...");
    rslt = DbiSetDirectory(hDb, (pCHAR) szTblDirectory);
    ChkRslt(rslt, "SetDirectory");

    Screen("    Attempt to open the %s table: \r\n"
           "        Error Expected: 'Encrypted dBASE tables not supported'...",
           szTblName);
    rslt = DbiOpenTable(hDb, (pCHAR) szTblName, (pCHAR) szTblType,
                        NULL, NULL, 0, dbiREADONLY, dbiOPENSHARED,
                        xltFIELD, FALSE, NULL, &hCur);
    ChkRslt(rslt, "OpenTable");

    if (hCur)
    {
        Screen("    Display the %s table...", szTblName);
        DisplayTable(hCur, uNumOfRecs);

        Screen("\r\n    Close the %s table...", szTblName);
        DbiCloseCursor(&hCur);
    }

    Screen("\r\n    Register the Login Callback...");

    // Allocate enough space for the data passed to the callback function.
    CallBackData3 = (pCHAR)malloc(100 * sizeof(CHAR));
    if (CallBackData3 == NULL)
    {
        CloseDbAndExit(&hDb);
        Screen("\r\n*** End of Example ***");
        return;
    }

    // Register the callback.
    rslt = DbiRegisterCallBack(NULL, cbDBASELOGIN, (UINT32) CallBackData3,
                               sizeof(CBLoginDesc), &CbInfo, CallBackFunc3);
    if(ChkRslt(rslt, "RegisterCallback") != DBIERR_NONE)
    {
        free(CallBackData3);
        CloseDbAndExit(&hDb);
        Screen("\r\n*** End of Example ***");
        return;
    }

    Screen("\r\n    Open the %s table...", szTblName);
    rslt = DbiOpenTable(hDb, (pCHAR) szTblName, (pCHAR) szTblType,
                        NULL, NULL, 0, dbiREADONLY, dbiOPENSHARED,
                        xltFIELD, FALSE, NULL, &hCur);
    ChkRslt(rslt, "OpenTable");

    if (hCur)
    {
        Screen("    Display the Table...");
        DisplayTable(hCur, uNumOfRecs);

        Screen("\r\n    Close the %s table...", szTblName);
        rslt = DbiCloseCursor(&hCur);
        ChkRslt(rslt, "CloseCursor");
    }

    // Unregister the callback by passing in NULL for the function.
    rslt = DbiRegisterCallBack(NULL, cbINPUTREQ, NULL, 0, NULL, NULL);
    if (ChkRslt(rslt, "RegisterCallBack") != DBIERR_NONE)
    {
        free(CallBackData3);
        CloseDbAndExit(&hDb);
        Screen("\r\n*** End of Example ***");
        return;
    }

    free(CallBackData3);

    Screen("\r\n    Close the database and exit IDAPI...");
    CloseDbAndExit(&hDb);

    Screen("\r\n*** End of Example ***");
}

//======================================================================
//  Name:   CallBackFunc3(ecbType, iClientData, pCbInfo)
//
//  Input:  ecbType     - Callback type
//          iClientData - Pointer to client information that is passed into
//                        the callback function
//          pCbInfo     - The callback structure that holds the information
//                        about the current state
//
//  Return: The action that should be taken
//
//  Description:
//          This function will be called from the BDE during the process
//          of opening the table.
//======================================================================
CBRType DBIFN
CallBackFunc3 (CBType ecbType, UINT32 iClientData, pVOID pCbInfo)
{
    CBLoginDesc *eCBInputDesc; // Variable to contain passed-in
                               //   information

    // Set to stop an unused variable warning.
    iClientData = iClientData;

    switch (ecbType)
    {
        // In case this is a restructure progress callback, display the
        //   information.
        case cbDBASELOGIN:

            eCBInputDesc = (CBLoginDesc far *)pCbInfo;

            strcpy(eCBInputDesc->szUserName, "TEST");
            strcpy(eCBInputDesc->szGroupName, "TEST");
            strcpy(eCBInputDesc->szUserPassword, "TEST");
            break;

        default:
            Screen("### In the callback function");
    }

    return cbrCHKINPUT;
}