You may want to write your own Handler if you are an IIS server administrator who wants the default RDS support, but more control over user requests and access rights.
The MSDFMAP.Handler implements the IDataFactoryHandler interface.
This interface has two methods, GetRecordset and Reconnect. Both methods require the CursorLocation property be set to adUseClient.
Both methods take arguments that appear after the first comma in the "Handler=" keyword. For example, "Handler=progid,arg1,arg2;" will pass an argument string of "arg1,arg2", and "Handler=progid" will pass a NULL argument.
This function is used to query the data source and create a new Recordset object using the arguments provided. The Recordset must be opened with adLockBatchOptimistic, and must not be opened asynchronously.
Syntax
conn The connection string.
args Arguments for the handler.
query The command text for making a query.
ppRS Pointer where the Recordset should be returned.
This function is used to update the data source. It will create a new Connection object and attach the given Recordset.
Syntax
conn The connection string.
args Arguments for the handler.
pRS A Recordset object.
This is the interface definition for IdataFactoryHandler that appears in the msdfhdl.idl file.
[
uuid(D80DE8B3-0001-11d1-91E6-00C04FBBBFB3),
version(1.0)
]
library MSDFHDL
{
importlib("stdole32.tlb");
importlib("stdole2.tlb");
// TLib : Microsoft ActiveX Data Objects 2.0 Library
// {00000200-0000-0010-8000-00AA006D2EA4}
#ifdef IMPLIB
importlib("implib\\x86\\release\\ado\\msado15.dll");
#else
importlib("msado20.dll");
#endif
[
odl,
uuid(D80DE8B5-0001-11d1-91E6-00C04FBBBFB3),
version(1.0)
]
interface IDataFactoryHandler : IUnknown
{
HRESULT _stdcall GetRecordset(
[in] BSTR conn,
[in] BSTR args,
[in] BSTR query,
[out, retval] _Recordset **ppRS);
// DataFactory will use the ActiveConnection property
// on the recordset after calling Reconnect.
HRESULT _stdcall Reconnect(
[in] BSTR conn,
[in] BSTR args,
[in] _Recordset *pRS);
};
};