{ errval.pas }
program ErrVal;

{$IfDef VER80}
uses SnipTool, SnipData, SysUtils, WinTypes, WinProcs,
     DbiProcs, DbiTypes, DbiErrs;
{$Else}
uses WinTypes, WinCrt, Strings, DbiProcs, DbiTypes, DbiErrs,
     SnipTool, SnipData;
{$EndIf}

{=====================================================================
   Code:   ErrVal();
 
   Input:  None.
 
   Return: None.
 
   Description:
           IDAPI functions return error codes to inform the calling
           program if the function succeded or failed. The return value
           will be equal to DBIERR_NONE when the function was
           successfull.
           This examples shows how to get information about an error
           when an IDAPI function returns a value other than DBIERR_NONE.
 ===================================================================== }

var
    rslt: DBIResult;       { Value returned from IDAPI functions }
    hDb: hDBIDb;        { Handle to the Database }
    Category: INT16;   { Category of the error }
    Code: INT16;       { Code of the error
                              (code within the category) }
    dbi_status: array[0..DBIMAXMSGLEN+1] of CHAR; { Error string }
    Message: array[0..DBIMAXMSGLEN+201] of CHAR;  { Message String }

begin
    Screen('*** Getting Error Information ***');
    InitOutput;

    { Open a Standard database (used to access Paradox and dBASE
      tables), by using a nil database type. Note that this will fail
      because we have not initialized IDAPI. }
    Screen('    Attempt to open the database...');
    Screen('        Error Expected - Engine not initialized.');
    rslt := DbiOpenDatabase('', nil, dbiREADWRITE, dbiOPENSHARED,
                           nil, 0, nil, nil, hDb);
    if (rslt <> DBIERR_NONE) then { Check for error }
    begin
        Screen('        Got an Error');

        { The ErrCat() macro returns the Category of the error }
        Screen('            Get the Category of the error...');
        Category := ErrCat(rslt);

        { The ErrCode() macro returns the Code within the Category of
          the error }
        Screen('            Get the Code of the Error...');
        Code := ErrCode(rslt);

        { The DbiGetErrorString() function returns the error string
          associated with the error message }
        Screen('            Get the Error String...');
        DbiGetErrorString(rslt, dbi_status);

        { Format the string which will display the information }
        StrPCopy(Message, '               Error! category: ['+
                 IntToStr(Category)+'] code: ['+IntToStr(Code)+
                 '] Message: '+dbi_status);

        { Display the information }
        Screen('            Display the Error information...');
        Screen(StrPas(Message));

    end;

    { Check for Re-Initialization Error }
    if (rslt = DBIERR_NOTINITIALIZED) then { Check if the the error }
    begin                                  { is the expected error }
        Screen('        Expected condition - IDAPI not Initialized');
    end
    else {received an error which we did not expect }
    begin
        Screen('        Unexpected Condition - terminating example');
    end;

    Screen('');
    CloseOutput;
    Screen('*** End of Example ***');

end.