Q131710: FIX: TYPE() Returns "" Instead of "U" For OleBoundControl

Article: Q131710
Product(s): Microsoft FoxPro
Version(s): MACINTOSH:3.0b; WINDOWS:3.0,3.0b,5.0
Operating System(s): 
Keyword(s): kbcode kbprogramming kbvfp kbvfp300bBUG kbvfp500aFIX kbvfp500bugkbbuglist kbfixlist
Last Modified: 15-FEB-2000

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The information in this article applies to:

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

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

Additional query words:

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Keywords          : kbcode kbprogramming kbvfp kbvfp300bBUG kbvfp500aFIX kbvfp500bug kbbuglist kbfixlist
Technology        : kbHWMAC kbOSMAC kbVFPsearch kbAudDeveloper kbVFP300bMac kbVFP300 kbVFP300b kbVFP500
Version           : MACINTOSH:3.0b; WINDOWS:3.0,3.0b,5.0
Issue type        : kbbug
Solution Type     : kbfix

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