Setting Up RDS to Use a Handler

If you plan to use an RDS handler, first complete Setting up RDS and then follow these handler-specific steps:

1. Configure the handler in a customization file. See The Handler Customization File.
2. Set the registry value for the key HKEY_LOCALMACHINE/SOFTWARE/MICROSOFT/DATAFACTORY/HANDLERINFO/ to HandlerRequired=1, which means that the handler specified in the following step must be used. Using the default value of 0 for this key means that a handler will be used only if one was specified by name in the following step. This registry key is changed by double-clicking the Handsafe.reg file (sets HandlerRequired to 1) or the Handunsf.reg file (sets HandlerRequired to 0). These registration files are installed with ADO 2.0. They can be found in the C:\Program Files\Common Files\System\MSADC folder.
3. Make the following variable setting, which causes the RDS Datafactory object not to query ADO but to use a handler instead. Specify which handler to use by setting the variable: RDS.Open "Handler=MSDFMAP.Handler" or RDS.Handler="MSDFMAP.Handler,FmLibMap.ini". "MSDFMAP.Handler" is the default handler provided by ADO; this is the place to give the name of a custom handler. If no handler is specified here, the Datafactory object's Query method will query through ADO (see step 4 of the preceding procedure). The CML/LitCrit application uses this default handler.

Now you are ready to follow the steps in Steps in RDS Data Retrieval (Using a Handler).

Note  The CML/LitCrit application uses an RDS customization handler to specify connection and command settings before they are used to access database data. As stated in this topic, you can require that a handler be used by setting the registry value for the key HKEY_LOCALMACHINE/SOFTWARE/MICROSOFT/DATAFACTORY/HANDLERINFO/ to HandlerRequired=1. If you do this however, the recordset that DTC used in the CML/LitCrit application on the Catalog.asp page silently fails because the handler denies access, and the grid control displays nothing.