12 replies to this topic

[big_daddy]

I was trying to help someone here in the support forum pass some variables between Excel/Word. In doing so I came to the conclusion AutoIt does not support ByRef variables through COM.

• Create a Word Document
• Press Alt-F11
• Double Click "ThisDocument"
• Paste the following macro
• Saveas "ByRef.doc"

Sub MacroTestByRef(ByRef v_Arg)
    v_Arg = "After"
End Sub

I would have expected the following to write "After" to the console, but instead it still has the value of "Before".

[/dev/null]

isn't that a know limitation?

From the help file: Obj/COM Reference

Limitations on COM Events in AutoIt
Some Objects (like the 'WebBrowser') pass arguments to their Event Functions 'by reference'. This is intended to allow the user change these arguments and passing it back to the Object. However, AutoIt uses it's own variable scheme, which is not compatible to COM variables. This means that all values from Objects need to be converted into AutoIt variables, thus loosing the reference to the original memory space. Maybe in the near future we can solve this limitation for you !

Edited by /dev/null, 21 June 2007 - 04:33 PM.

[big_daddy]

I thought I'd remembered reading something like that before. Although this has nothing to do with events, I'm guessing it is due to the same limitation.

[DaleHohm]

Well shoot. I use byRef throughout IE.au3 thinking that I was saving resources by no cloning the Object variable over and over again... if the architecture requires cloning anyway, the the restrictions that byRef creates are unwarranted (primarily not being able to nest _IE function calls inside eachother).

Need to do some of my own testing...

Dale

[big_daddy]

Any developers care to comment?

[big_daddy]

I still think this would be a great limitation to overcome.

[Valik]

I don't think it's going to happen. I've mentioned it before, but we can't even use ByRef on built-in functions. It's not a trivial issue to solve, particularly since nobody wants to work on it. Until we figure out how to modify parameters ByRef for built-in functions, COM isn't going to get it either.

[GioVit]

I don't think it's going to happen. I've mentioned it before, but we can't even use ByRef on built-in functions. It's not a trivial issue to solve, particularly since nobody wants to work on it. Until we figure out how to modify parameters ByRef for built-in functions, COM isn't going to get it either.

why not considere events as a special type of function and define it with a special keyword (like "Event Func") so it can only be called by the COM object and have a different behaviour when pass arguments by reference?

because events are mostly called by COM object not by user

Sorry if I can't be more explicit, my english is limited

GioVit

[Valik]

What do events have to do with by reference? An event can't take a parameter by reference.

[GioVit]

What do events have to do with by reference? An event can't take a parameter by reference.

Here is an example

in the next code I define an event called "EdEvent_EndEdit" it have 4 arguments:

1) if you add to any of this arguments the keyword ByRef then an error occurs (Expected a variable in user function call.)
2) if you don't then you can't control the behavior of the edited cell because the changes in the arguments value are ingnored by the object

if you dont have "OWC11.dll" you can download it Here

The help file of this object, after installed, is in:
"[Drive where you intalled it]:\Program Files\Common Files\Microsoft Shared\Web Components\11\1033\OWCDSS11.CHM"

And the expalnation of the event "EndEdit" can be found in the help file with this path:
"Programming Information/Events/E/EndEdit Event"

AutoIt        expandcollapse  popup

#include <GUIConstants.au3>
#NoTrayIcon

;Vars
Dim Const $xlToRight = -4161 ;0xFFFEFBF
dim Const $ssClear = 10002

Dim $oMyError
Global $oExcel, $oEvent
Global $OrdDef [1][4] = [[0,0,0,0]]
Global $OrdSaved = True
Global $CurOp = "", $CurRow, $CurCol

$oMyError = ObjEvent("AutoIt.Error","MyErrFunc") ; Install a custom error handler 
;MsgBox(64,"Windowdir", @WindowsDir)
InitExcel()

;Declare objects


   
;Main Gui

GuiCreate("Excel Object", 802, 590,(@DesktopWidth-802)/2, (@DesktopHeight-590)/2 , $WS_OVERLAPPEDWINDOW + $WS_VISIBLE + $WS_CLIPSIBLINGS)

$GUI_ActiveX = GUICtrlCreateObj ($oExcel, 10, 10 , 780 , 550)
GUICtrlSetState($GUI_ActiveX, $GUI_HIDE)
;GUICtrlSetStyle ( $GUI_ActiveX,  $WS_HIDE )
;GUICtrlSetResizing ($GUI_ActiveX,$GUI_DOCKAUTO)    ; Auto Resize Object
    
GuiSetState()
EditOrder()
While 1
    $msg = GuiGetMsg()
    Select
    Case $msg = $GUI_EVENT_CLOSE
        ExitLoop
    EndSelect
WEnd
Exit

Func InitExcel()
    $oExcel = ObjCreate("OWC11.spreadsheet"); Default to 2003
    If not IsObj($oExcel) Then
        $oExcel = ObjCreate("OWC10.spreadsheet"); Office XP    
    EndIf
    IF not IsObj($oExcel) Then
        $oExcel = ObjCreate("OWC00.spreadsheet"); Office 2000
    EndIf
    If Not IsObj($oExcel) Then
       MsgBox(0,"Reply","No se encontro el Objeto Excel",4)
       Exit
   EndIf
    $oEvent = ObjEvent($oExcel,"EdEvent_")

EndFunc


Func EditOrder()
    $CurOp = "EditOrder"
    GUICtrlSetState($GUI_ActiveX, $GUI_SHOW)
       with $oExcel
            .Activewindow.DisplayWorkbookTabs = False
            .DisplayToolbar = False
            .Autofit = True
            .MoveAfterReturnDirection = $xlToRight
            $oEvent = ObjEvent($oExcel,"EdEvent_")
            GUICtrlSetState($GUI_ActiveX, $GUI_SHOW)
        EndWith
    EndFunc 
    

Func EdEvent_EndEdit($Accept, $FinalValue, $Cancel, $ErrorDescription)
    MsgBox(64,"FinalValue", $FinalValue.Value)
    if $FinalValue > 4 Then
        $FinalValue.Value = $FinalValue.Value * 2
    Else
        $Cancel.Value = True
    EndIf
EndFunc


    
;This is Sven P's custom error handler
Func MyErrFunc()
  $HexNumber=hex($oMyError.number,8)
  Msgbox(0,"AutoItCOM Test","We intercepted a COM Error !"       & @CRLF  & @CRLF & _
             "err.description is: "    & @TAB & $oMyError.description    & @CRLF & _
             "err.windescription:"     & @TAB & $oMyError.windescription & @CRLF & _
             "err.number is: "         & @TAB & $HexNumber              & @CRLF & _
             "err.lastdllerror is: "   & @TAB & $oMyError.lastdllerror   & @CRLF & _
             "err.scriptline is: "     & @TAB & $oMyError.scriptline     & @CRLF & _
             "err.source is: "         & @TAB & $oMyError.source         & @CRLF & _
             "err.helpfile is: "       & @TAB & $oMyError.helpfile       & @CRLF & _
             "err.helpcontext is: "    & @TAB & $oMyError.helpcontext _
            )
  SetError(1) ; to check for after this function returns
Endfunc

also the AutoIt help File say

Limitations on COM Events in AutoIt



Some Objects (like the 'WebBrowser') pass arguments to their Event Functions 'by reference'. This is intended to allow the user change these arguments and passing it back to the Object. However, AutoIt uses it's own variable scheme, which is not compatible to COM variables. This means that all values from Objects need to be converted into AutoIt variables, thus loosing the reference to the original memory space. Maybe in the near future we can solve this limitation for you !

Is there other way to solve this?

Thanks in advance

[Valik]

Ahh, I guess I should have re-read the thread to see what it was really about.

I've just opened ticket #134 so this won't get lost. It's incredibly low priority, I have a million other things to do first.

[GioVit]

Ahh, I guess I should have re-read the thread to see what it was really about.

I've just opened ticket #134 so this won't get lost. It's incredibly low priority, I have a million other things to do first.

Thank you anyway

I hope other users understand the importance of this change, in order to increase the priority.

Thanks again Valik

[BrettF]

It gets done when it gets done. No questions ask. They develop this in their own time!