REXX Tips & Tricks:Development Tools

These sections contain information about some REXX development tools, e.g. VX/REXX.

(Well, at this time the section about VX/REXX is the only one - but with some help of others there may be more in the future.)

VX/REXX ODK

* Name VX/REXX Object Development Tool

• Version
• Author Watcom
• Distrib. ?
• Type Toolkit for C programmers
• Price -
• Source Internet

• Name: VXODK.*
• Note /w source

This is the Object Development Tool for VX/REXX from Watcom. You need this if you want to build new objects for VX/REXX.

Please note that I do not know if the distribution of the toolkit is legal.

VX/REXX Buglist

This section is written & Copyright by Bastian Maerkisch

Inofficial VX/REXX buglist (1.08.2001)

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ComboBox / DropDownComboBox object:

these objects don't handle the LM_INSERTMULTITEMS PM messages (unlike 'ordinary' PM combo boxes)

fix: send this message to child with id 0x instead

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ComboBox object:

combo boxes no longer accept input from keyboard if they have a 'KeyPress' event routine assigned

fix: [if you know any, please submit!]

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Accelerators: [feature ;)]

accelerators of windows with the 'Visible' property set to '0' don't have their accelerators deactivated.

fix: [if you know any, please submit!]

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KeyString property:

[at least on german keyboards] the comma on the numeric key block is always assigned '{Del}' independent from current NumLock setting

fix: [if you know any, please submit!]

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PostEvent method: [undocumented bahaviour]

'FocusObject' parameter is defined for retrieval by VRInfo [not documented] [there might be even more - not checked]

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Button / Verify Event: [feature]

if a button has 'NoPointerFocus' set to '1' this disables the generation of 'Verify' events when the button is activated

fix: you might consider to fix this behaviour by adding the following code to the button's 'Click' event routine

AnyButton_click: procedure         /* important: only local signal handler */
    object = VRInfo( "Object" )
    verified = VRInfo( "Verified" )      /* object of previous verify, if any */
    focus  = VRMethod( "Screen", "GetFocusWindow", "Object" )
                                        /* get real focus object */

    if VRGet( object, "NoPointerFocus" ) & \         /* handle verifies ? */
       (verified \= focus) & \                       /* verified it before ? */
       (focus \= '') then do                   /* is there a focus object ? */

      signal on syntax name AnyButton_Syntax
      verify = VRGet( focus, "Verify" )
      signal off syntax
                      /* rude way to determine if object has a verify event, */
                      /* could have used 'ListProperties' method instead     */

      if verify \= '' then do             /* does object have verify event ? */
        ok = VRMethod( focus,  "PostEvent", "Verify" )
                                        /* post verify event to focus object */
        ok = VRMethod( object, "PostEvent", "Click", "Verified", focus_window )
                              /* re-post click event to button  and give     */
                              /* the verify event routine a chance to cancel */
        return
      end
    end
  AnyButton_Syntax:

    /* go on with the real work */
    /* ... */
  return

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VRLoadSecondary function:

standard 'VRLoadSecondary' in section 'Main' generates NoValue exceptions

fix: replace VRLoadSecondary in Main section with the following code

VRLoadSecondary:
      __vrlsWait = abbrev( 'WAIT', translate(arg(2)), 1 )
      if __vrlsWait then
          call VRFlush
      if arg(3,"Exists") then
          __vrlsParent = arg(3)
      else
          __vrlsParent = VRWindow()
      /*    __vrlsParent = VRInfo( 'Window' ) */
      __vrlsHWnd = VRLoad( __vrlsParent, VRWindowPath(), arg(1) )
      if __vrlsHWnd = '' then signal __vrlsDone
      if \ __vrlsWait    then signal __vrlsDone
      call VRSet __vrlsHWnd, 'WindowMode', 'Modal'
      if( symbol('__vrlsWindows.0') \== 'VAR' ) then
          __vrlsTmp = 1
      else
          __vrlsTmp = __vrlsWindows.0 + 1
      __vrlsWindows.__vrlsTmp = VRWindow( __vrlsHWnd )
      __vrlsWindows.0 = __vrlsTmp
      do while( VRIsValidObject( VRWindow() ))
          __vrlsEvent = VREvent()
        interpret __vrlsEvent
      end
      __vrlsTmp = __vrlsWindows.0
      __vrlsWindows.0 = __vrlsTmp - 1
      call VRWindow __vrlsWindows.__vrlsTmp
      __vrlsHWnd = ''
  __vrlsDone:
  return __vrlsHWnd

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VX/REXX IDE and ObjectRexx:

VX/REXX's routine to retrieve error information from a program 'VRERRTXT' crashes on line 3, no error information

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C/S edition bugs

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Query object: [severe] the 'RowData' method does not check if there actually is data available; if not calling 'RowData' might cause system hangs!

fix: check for data first (e.g. with 'MoveFirst')

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Query object and QueryManager:

the 'Search' method and QueryManager interpret all colons in SQLStatement as references to variables even if they are inside strings

fix: [not known]

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QueryManager:

query manager can't properly handle references to stem variables in 'SQLStatement'

fix: just ignore it - the 'Query' object can handle them

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Query object: Bound variables

only numeric fields are properly supported by the 'BindVar' method, since no string delimiters are placed around the value. This leads to errors when interpreting the generated events.

fix: no general fix - don't use it, use 'RowData' method instead

If you really need to use it you might consider the following: Use a specific naming convention for bound variables: e.g. 'BoundVar'xxxx Insert the following code into the main loop in 'Main' section:

 
      ...
      do while( \ VRGet( _VREPrimaryWindow, "Shutdown" ) )
        _VREEvent = VREvent()

        /* hack for bound vars */
        if abbrev(_VREEvent,'BoundVar',8) then do
          parse var _VREEvent __FixVar__ '=' __FixValue__
          _VREEvent = __FixVar__  "= '" || strip(__FixValue__,'L') || "'"
        end

        interpret _VREEvent
      end
      ...

[btw.: Does anybody know why it was implemented using events in the first place?]

DrDialog Buglist

This section contains a list of known bugs in DrDialog.

"There is a problem running DrDialog programs under Object REXX if they use DrsAide (as shipped) controls. Because Object REXX parses the entire file before running, many times syntax errors which would go undetected under "Classic" REXX are in fact detected. There is just such a syntax error in the DrsAide utility.

To fix the problem, open the DRSAIDE.RES file from the DrDialog File Menu option. Double-Click the ICONBUTTON (the only control visible other than the DIALOG). The DrRexx Code editor should appear with the ICONBUTTON section open. Click the "Drop-" tab and use the spin-button under the edit window to bring up the Class code. At the very end, on its own line, type END. Save the file. And now everything should work."

Source: Thos Davis

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Note (07/04/2003):

The slidercontrols of DrDialog are buggy.

Workaround: Use the Scrollbars instead

Thanks to Klaus Staedtler for this information

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