Why IsObj = 0 and VarGetType = Object ???

[mLipok]

 

 

#AutoIt3Wrapper_Au3Check_Parameters=-d -w 1 -w 2 -w 3 -w- 4 -w 5 -w 6 -w 7
#Tidy_Parameters=/sort_funcs /reel

_Example()
Func _Example()
    Local $oErrorHandler = ObjEvent("AutoIt.Error", "_ErrFunc")
    #forceref $oErrorHandler

    Local $oXmlDoc = ObjCreate("Msxml2.DOMDocument.3.0")
    $oXmlDoc.loadXml('<start></start>')
    If @error Then MsgBox(0, '1. @error', @error)
    If $oXmlDoc.parseError.errorCode Then MsgBox(0, '1. $oXmlDoc.parseError.', $oXmlDoc.parseError.errorCode & @CRLF & $oXmlDoc.parseError.reason)

    Local $oNode_Selected = $oXmlDoc.selectSingleNode('/book')
    If @error Then MsgBox(0, '2. @error', @error)
    MsgBox(0, IsObj($oNode_Selected), VarGetType($oNode_Selected))



EndFunc   ;==>_Example



Func _ErrFunc($oError)
    ConsoleWrite(@ScriptName & " (" & $oError.scriptline & ") : ==> COM Error intercepted !" & @CRLF & _
            @TAB & "err.number is: " & @TAB & @TAB & "0x" & Hex($oError.number) & @CRLF & _
            @TAB & "err.windescription:" & @TAB & $oError.windescription & @CRLF & _
            @TAB & "err.description is: " & @TAB & $oError.description & @CRLF & _
            @TAB & "err.source is: " & @TAB & @TAB & $oError.source & @CRLF & _
            @TAB & "err.helpfile is: " & @TAB & $oError.helpfile & @CRLF & _
            @TAB & "err.helpcontext is: " & @TAB & $oError.helpcontext & @CRLF & _
            @TAB & "err.lastdllerror is: " & @TAB & $oError.lastdllerror & @CRLF & _
            @TAB & "err.scriptline is: " & @TAB & $oError.scriptline & @CRLF & _
            @TAB & "err.retcode is: " & @TAB & "0x" & Hex($oError.retcode) & @CRLF & @CRLF)
EndFunc   ;==>_ErrFunc_CustomUserHandler

Whats wrong with this line:

MsgBox(0, IsObj($oNode_Selected), VarGetType($oNode_Selected))

Why IsObj = 0 and VarGetType = Object ??? How it is possible.

 

[Danyfirex]

I think it happens because the node is empty so  You have an object empty  you can't work with so autoit isobj check if you can work with if node is nothing isobj says "no you can not use this object". but if your node is not empty isobj says "yes you can work with this object"

So I Think is not problem of Autoit Funtion if you check with vbs you will see that happens same.

I mean this:

vbs Code

Set objXMLDoc = CreateObject("Msxml2.DOMDocument.3.0") 
objXMLDoc.load("file.xml") 

Set Node = objXMLDoc.documentElement.selectSingleNode("Word/Spanish")
MsgBox("Is Object Type: " & (Vartype(Node)=vbObject) & vbCrlf & "IsObj: " & not(Node Is Nothing))
 
 Set Node = objXMLDoc.documentElement.selectSingleNode("notExist")
 MsgBox("Is Object Type: " & (Vartype(Node)=vbObject) & vbCrlf & "IsObj: " & not(Node Is Nothing))

Autoit Code

_Example()
Func _Example()


$objXMLDoc = ObjCreate("Msxml2.DOMDocument.3.0")
$objXMLDoc.load("file.xml")

$Node = $objXMLDoc.documentElement.selectSingleNode("Word/Spanish")
msgbox(0,"","IsOject:" & IsObj($Node) & @CRLF & "IsObject Type: " & VarGetType($Node))

$Node = $objXMLDoc.documentElement.selectSingleNode("notExist")
 msgbox(0,"","IsOject:" &IsObj($Node) & @CRLF & "IsObject Type: " & VarGetType($Node))


EndFunc   ;==>_Example

file.xml

<Vocabulary> 
   <Word type="noun" level="1"> 
      <English>cat</English> 
      <Spanish>gato</Spanish> 
   </Word> 
   <Word type="verb" level="1"> 
      <English>speak</English> 
      <Spanish>hablar</Spanish> 
   </Word> 
   <Word type="adj" level="1"> 
      <English>big</English> 
      <Spanish>grande</Spanish> 
   </Word> 
</Vocabulary>

Saludos

[mLipok]

So this is like Ubound()

better to check VarGetType ? (in some cases not particularly here)

And again MSDN selectSingleNode Method do not mention about this:

Return Value
An object. Returns the first node that matches the given pattern-matching operation. If no nodes match the expression, returns a null value.

 

Edited September 9, 2015 by mLipok
wording

[Danyfirex]

I prefer keep using isobj.

_Example()
Func _Example()

Local $oErrorHandler = ObjEvent("AutoIt.Error", "_ErrFunc")
    #forceref $oErrorHandler
$objXMLDoc = ObjCreate("Msxml2.DOMDocument.3.0")
$objXMLDoc.load("file.xml")

$Node = $objXMLDoc.documentElement.selectSingleNode("Word/Spanish")
if IsObj($Node) then msgbox(0,$Node.text,"IsOject:" & IsObj($Node) & @CRLF & "IsObject Type: " & VarGetType($Node))

$Node = $objXMLDoc.documentElement.selectSingleNode("notExist")
if IsObj($Node) then msgbox(0,$Node.text,"IsOject:" &IsObj($Node) & @CRLF & "IsObject Type: " & VarGetType($Node))


EndFunc   ;==>_Example

Func _ErrFunc($oError)
    ConsoleWrite(@ScriptName & " (" & $oError.scriptline & ") : ==> COM Error intercepted !" & @CRLF & _
            @TAB & "err.number is: " & @TAB & @TAB & "0x" & Hex($oError.number) & @CRLF & _
            @TAB & "err.windescription:" & @TAB & $oError.windescription & @CRLF & _
            @TAB & "err.description is: " & @TAB & $oError.description & @CRLF & _
            @TAB & "err.source is: " & @TAB & @TAB & $oError.source & @CRLF & _
            @TAB & "err.helpfile is: " & @TAB & $oError.helpfile & @CRLF & _
            @TAB & "err.helpcontext is: " & @TAB & $oError.helpcontext & @CRLF & _
            @TAB & "err.lastdllerror is: " & @TAB & $oError.lastdllerror & @CRLF & _
            @TAB & "err.scriptline is: " & @TAB & $oError.scriptline & @CRLF & _
            @TAB & "err.retcode is: " & @TAB & "0x" & Hex($oError.retcode) & @CRLF & @CRLF)
EndFunc   ;==>_ErrFunc_CustomUserHandler

Saludos