FIX: TYPE() Returns "" Instead of "U" For OleBoundControl

• Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0
• Microsoft Visual FoxPro for Macintosh, version 3.0b

SYMPTOMS

If you run a form containing an OleBoundControl object and the TYPE() function attempts to verify the type of an undefined property of the object, the TYPE() function returns an empty string ("") instead of the expected "U" value.

RESOLUTION

If your application uses the return value of the TYPE() function, test for an empty value ("") as a return value for all cases where an object uses the OleBoundControl as a BaseClass. For example:

DO CASE

   CASE <object>.BaseClass="Oleboundcontrol"
      IF TYPE('<form>.<object>.UndefProp')="U" ;
         OR TYPE ('<form>.<object>.UndefProp')=""
         *Place code here
      ELSE
         *Place code here
      ENDIF

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem has been fixed in Visual FoxPro 5.0a.

MORE INFORMATION

Steps to Reproduce Problem

1. Create a form.

2. On the DataEnvironment menu, click Add Table.

3. In the Add Table dialog box, select Tables, and then select the Employee table located in the SAMPLES\DATA directory.

4. Click the OleBoundControl control on the Form Controls toolbar, and place the control on the form. Then modify the ControlSource property of the control to this:

   ControlSource: Employee.Photo

5. Place a command button on the form, and modify its Click event handler to include this code:

   SKIP Thisform.Refresh

6. Save the form as FRMTEST, and run it.

7. Use the following code in the Debug window (for Visual FoxPro 3.x versions) or the Watch window in the Visual FoxPro 5.0 Debugger to verify the return value of the OleBoundControl control:

   TYPE('Frmtest.OleBoundControl1.BadProp') && Property does not exist

Keywords          : buglist3.00 buglist3.00b buglist5.00 FxprgGeneral vfoxwin vfpfix5.0a kbcode kbprg kbbuglist kbfixlist
Version           : 3.0 3.0b 5.0
Platform          : MACINTOSH WINDOWS
Issue type        : kbbug
Solution Type     : kbfix