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Q279409: BUG: WebClass ProcessTag Event Fails to Execute

Article: Q279409
Product(s): Microsoft Visual Basic for Windows
Version(s): 6.0,6.0 SP4
Operating System(s): 
Keyword(s): kbtemplate kbCOMt kbVBp600bug kbVisID600bug kbWebClasses kbGrpDSASP kbDSupport kbEvent
Last Modified: 28-JUN-2001

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The information in this article applies to:

- Microsoft Visual Basic Learning Edition for Windows, version 6.0 
- Microsoft Visual Basic Professional Edition for Windows, version 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 SP4 
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SYMPTOMS
========

When you run a WebClass project from within Visual Basic 6.0 Service Pack 4, and
there is more than one WebClass tag in a Web document, the WebClass ProcessTag
events may fail to execute. This does not occur if you browse the Active Server
Pages (ASP) page directly.

CAUSE
=====

This problem occurs if the previous execution of the ProcessTag event did not
change the value of the TagContents variable. If your ProcessTag event never
sets or modifies the value of the TagContents variable, every other tag is
skipped.

RESOLUTION
==========

To resolve this problem, while you are developing the WebClass project from
within Visual Basic, set or modify the value of the TagContents variable every
time the ProcessTag event executes. To do this, add the following line at the
beginning of your ProcessTag event:

  TagContents = TagContents

This line can be commented out or removed when the Web project is put into
production, but it must be put back next time you run the WebClass project from
within Visual Basic.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

1. Use the following template to create a WebClass project:

  <html>
  <head><title>ProcessTag Event Test</title></head>
  <body>
  <h1>ProcessTag Event Test</h1>
  The following should show three lines:  One, abc & Three<br>
  Instead, it shows these three lines:  One, Two & Three<br>
  To fix this problem, uncomment the code:  TagContents = TagContents<hr>
  <WC@ONE>One</WC@ONE><br>
  <WC@TWO>Two</WC@TWO><br>
  <WC@THREE>Three</WC@THREE><br>
  </form>
  </body>
  </html>

2. In the WebClass project, paste the following code:

  Private Sub TagTemplate_ProcessTag(ByVal TagName As String, _
          TagContents As String, SendTags As Boolean)
      
      'Uncomment the following line to correct the problem.
      'TagContents = TagContents
      
      Select Case TagName
      Case "WC@ONE"
          'Do some work
      Case "WC@TWO"
          'Do some work
          TagContents = "abc"
      Case "WC@THREE"
          'Do some work
      Case Else
          'Do some work
      End Select
  End Sub

  Private Sub TagTemplate_Respond()
      TagTemplate.WriteTemplate
  End Sub

  Private Sub WebClass_Start()
      Set NextItem = TagTemplate
  End Sub

3. After you uncomment the following line of code:

  TagContents = TagContents

  you must refresh the page in the browser to see the change.

For more detailed information on how to create a WebClass project in Visual
Basic, see our sample projects at the following Microsoft Developer Network
(MSDN) Web sites:

  WCDemo Sample Project
  http://msdn.microsoft.com/library/devprods/vs6/vbasic/vb98/vbsmpwebclassdemoapplication(wcdemovbp)professionalenterpriseedition.htm

  Support1 Sample Project
  http://msdn.microsoft.com/library/devprods/vs6/vbasic/vb98/vbsmpsupportapplicationprofessionalenterpriseeditions.htm

  Support1 WebClass Tutorial
  http://msdn.microsoft.com/library/devprods/vs6/vbasic/vbcon98/vbhowCreatingaWebclass.htm

REFERENCES
==========

For additional information, click the article numbers below to view the articles
in the Microsoft Knowledge Base:

  Q192035 PRB: Do Not Use a WebClass ProcessTag Inside an HTML Tag

  Q234317 FIX: HTML Page Truncated with Visual Studio SP3 WebClass Run Time
  when Running in the VB IDE


For more information on sample Visual Basic projects, see the following MSDN
article:

  http://msdn.microsoft.com/library/devprods/vs6/vbasic/VBRef98/vbsamppage.htm

Additional query words: web class

======================================================================
Keywords          : kbtemplate kbCOMt kbVBp600bug kbVisID600bug kbWebClasses kbGrpDSASP kbDSupport kbEvent 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVB600 kbVB600SP4
Version           : :6.0,6.0 SP4
Issue type        : kbbug
Solution Type     : kbpending

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