How Visual FoxPro Organizes and Accesses Wizards

• Microsoft Visual FoxPro for Windows, version 3.0

SUMMARY

This article describes how Visual FoxPro knows that a Wizards exists and when to use it.

MORE INFORMATION

When you install Visual FoxPro, the _Wizard system memory variable is initialized to point to the application that will function as the main controller for all the wizards. By default, the variable contains WIZARD.APP, installed in the main Visual FoxPro directory. This application is activated each time you choose to run a wizard.

WIZARD.APP uses a registration table named WIZARD.DBF to store Information regarding the various wizards and to determine which Wizard to run. This table has the following structure:

Field    Field Name    Type        Width  Dec  Index  Collate  Nulls

    1    NAME          Character      45                          No
    2    DESCRIPT      Memo            4                          No
    3    BITMAP        Memo            4                          No
    4    TYPE          Character      20                          No
    5    PROGRAM       Memo            4                          No
    6    CLASSLIB      Memo            4                          No
    7    CLASSNAME     Memo            4                          No
    8    PARMS         Memo            4                          No
** Total **                           90

The Type field determines the Visual FoxPro File Type that the Wizard is associated with. For example, if the Type is REPORT, then that Wizard will be opened whenever you choose to create a new Report. If two or more wizards are of the same Type, the Wizard Selection dialog is displayed when you choose to run a wizard. The dialog lists the various wizards for the specific file type.

The contents of the Description field are displayed in the Description box of the Wizard Selection dialog.

When the user runs a certain wizard, WIZARD.APP runs the program specified in the Program field of the wizard. If the program is not in the Wizards directory, you must specify the path. If the Program field is blank, an instance of the class, as specified by the Classlib and Classname fields, is created.

The Parms field can be used to specify parameters sent to the Wizard when it is executed. For example, WZREPORT.APP contains the Report, One-To-Many Report, and Group/total Report Wizards. Therefore, depending on which wizard you select, the Parms field is used to pass REPORT, 1MANY, or the GROUP parameters respectively to WZREPORT.APP to determine which specific Report Wizard is to be activated.