The Data Handler class is a custom, or non-visual, Visual FoxPro class. In a VPM Enterprise application the Data Handler object is instantiated from this class whenever data handling functionality is needed. In the application object and forms the Data Handler object’s properties and methods can be referenced or called using the _SCREEN.oApp.oVPMDataHandler and ThisForm.oVPMDataHandler object references, respectively.

The VPM Enterprise-level Data Handler class is named “VPMDataHandler”, and it is located in the VPMDATAHANDLER.VCX class library. The PRODATAHANDLER.VCX class library contains a subclass of VPMDataHandler named “ProDataHandler”. The Data Handler object is instantiated from the ProDataHandler class. However, all of the Data Handler class code is in the VPMDataHandler class.

Class Browser

If you want to thoroughly explore this class, open the class library in the Class Browser, which you can run from the VPM Enterprise Tools menu. Select the class name in the class list. Click on the Class Browser’s View Class Code button to have the Class Browser export the class code to a Window. Then, print the class code. As you view the class code, properties will appear like memory variables and methods will appear as procedures.


VPMDataHandler Class Properties