How to add parent node in Vb.NET

[neerajb]

Hi,

I am having an XML document(input. xml) which is showing the menu heirarchy
used in my application.My requirement is to add "submenu" tag to those
menuitems who are having the child menuitems as shown in output.xml.
I am using VB.NET framework 1.1.

Please Help, i have already invested my 2 days but unable to build the logic
as input xml may be having any level of nesting of menuitems.

input.xml
*************** *************** *********
<menu>
<menuItem>
<text>HOME</text>
<javascriptcomm and>opennewwind ow('home.aspx') </javascriptcomma nd>
<cssclass>off </cssclass>
<MENU_ID>1</MENU_ID>
</menuItem>
<menuItem>
<text>QUERY</text>
<javascriptcomm and>openPopup(' fundSearch.aspx ','Search', 580,
200)</javascriptcomma nd>
<cssclass>off </cssclass>
<MENU_ID>2</MENU_ID>
</menuItem>
<menuItem>
<text>REPORTS </text>
<cssclass>off </cssclass>
<MENU_ID>3</MENU_ID>
<menuItem>
<text>Standar d Reports</text>
<MENU_ID>5</MENU_ID>
<PRNT_MENU_ID>3 </PRNT_MENU_ID>
<menuItem>
<text>PM Tenure</text>
<MENU_ID>7</MENU_ID>
<PRNT_MENU_ID>5 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Performan ce</text>
<MENU_ID>8</MENU_ID>
<PRNT_MENU_ID>5 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Fee & Expenses</text>
<MENU_ID>9</MENU_ID>
<PRNT_MENU_ID>5 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Fact Sheet PDFs</text>
<MENU_ID>10</MENU_ID>
<PRNT_MENU_ID>5 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Fund Facts</text>
<MENU_ID>11</MENU_ID>
<PRNT_MENU_ID>5 </PRNT_MENU_ID>
</menuItem>
</menuItem>
<menuItem>
<text>Custom Reports</text>
<MENU_ID>6</MENU_ID>
<PRNT_MENU_ID>3 </PRNT_MENU_ID>
<menuItem>
<text>Spectrums </text>
<MENU_ID>12</MENU_ID>
<PRNT_MENU_ID>6 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Performan ce</text>
<MENU_ID>13</MENU_ID>
<PRNT_MENU_ID>6 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Descripti ons</text>
<MENU_ID>14</MENU_ID>
<PRNT_MENU_ID>6 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Fund Actions</text>
<MENU_ID>15</MENU_ID>
<PRNT_MENU_ID>6 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Inv Svcs Only</text>
<MENU_ID>16</MENU_ID>
<PRNT_MENU_ID>6 </PRNT_MENU_ID>
</menuItem>
</menuItem>
</menuItem>
<menuItem>
<text>HELP</text>
<cssclass>off </cssclass>
<MENU_ID>4</MENU_ID>
<menuItem>
<text>FAQs</text>
<MENU_ID>17</MENU_ID>
<PRNT_MENU_ID>4 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>How To</text>
<MENU_ID>18</MENU_ID>
<PRNT_MENU_ID>4 </PRNT_MENU_ID>
</menuItem>
</menuItem>
</menu>

output.xml
*************** *************** *************** ********
<menu>
<menuItem>
<text>HOME</text>
<javascriptcomm and>opennewwind ow('home.aspx') </javascriptcomma nd>
<cssclass>off </cssclass>
<MENU_ID>1</MENU_ID>
</menuItem>
<menuItem>
<text>QUERY</text>
<javascriptcomm and>openPopup(' fundSearch.aspx ','Search', 580,
200)</javascriptcomma nd>
<cssclass>off </cssclass>
<MENU_ID>2</MENU_ID>
</menuItem>
<menuItem>
<text>REPORTS </text>
<cssclass>off </cssclass>
<MENU_ID>3</MENU_ID>
<submenu>
<menuItem>
<text>Standar d Reports</text>
<MENU_ID>5</MENU_ID>
<PRNT_MENU_ID>3 </PRNT_MENU_ID>
<submenu>
<menuItem>
<text>PM Tenure</text>
<MENU_ID>7</MENU_ID>
<PRNT_MENU_ID>5 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Performan ce</text>
<MENU_ID>8</MENU_ID>
<PRNT_MENU_ID>5 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Fee & Expenses</text>
<MENU_ID>9</MENU_ID>
<PRNT_MENU_ID>5 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Fact Sheet PDFs</text>
<MENU_ID>10</MENU_ID>
<PRNT_MENU_ID>5 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Fund Facts</text>
<MENU_ID>11</MENU_ID>
<PRNT_MENU_ID>5 </PRNT_MENU_ID>
</menuItem>
</submenu>
</menuItem>
<menuItem>
<text>Custom Reports</text>
<MENU_ID>6</MENU_ID>
<PRNT_MENU_ID>3 </PRNT_MENU_ID>
<submenu>
<menuItem>
<text>Spectrums </text>
<MENU_ID>12</MENU_ID>
<PRNT_MENU_ID>6 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Performan ce</text>
<MENU_ID>13</MENU_ID>
<PRNT_MENU_ID>6 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Descripti ons</text>
<MENU_ID>14</MENU_ID>
<PRNT_MENU_ID>6 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Fund Actions</text>
<MENU_ID>15</MENU_ID>
<PRNT_MENU_ID>6 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>Inv Svcs Only</text>
<MENU_ID>16</MENU_ID>
<PRNT_MENU_ID>6 </PRNT_MENU_ID>
</menuItem>
</submenu>
</menuItem>
</submenu>
</menuItem>
<menuItem>
<text>HELP</text>
<cssclass>off </cssclass>
<MENU_ID>4</MENU_ID>
<submenu>
<menuItem>
<text>FAQs</text>
<MENU_ID>17</MENU_ID>
<PRNT_MENU_ID>4 </PRNT_MENU_ID>
</menuItem>
<menuItem>
<text>How To</text>
<MENU_ID>18</MENU_ID>
<PRNT_MENU_ID>4 </PRNT_MENU_ID>
</menuItem>
</submenu>
</menuItem>
</menu>

Thanks & Regards,
Neeraj

[Cerebrus]

Hi,

I'm not sure I understand you correctly, but I think you need to insert
a <subMenu> element before each nested <menuItem> element. In other
words, you want to convert input.xml so that it looks like output.xml
???

Is that so ? If so, could you post whatever logic you have come up with
till now ?

Regards,

Cerebrus.

[dickster]

I'm having trouble getting an Xpath Expression to pick out the relevant
nodes

e.g.
descendant::men uItem[parent::menuIte m][not(preceding-sibling::menuIt em)]

Cerebus - I Would like to see to insert a new parent node around the
relevant menuItem node after having got the relevant nodes in a
nodelist

i.e.

xdoc.Load("xpat h.xml")

Dim nl As XmlNodeList = xdoc.DocumentEl ement. _
SelectNodes("de scendant::menuI tem[parent::menuIte m][not(preceding-sibling::menuIt em)]")

For Each xnode In nl

txEle = xdoc.CreateElem ent("submenu")
txEle.AppendChi ld(xnode)

'Now how do we update xdoc
'replacing xnode with txEle
' because at this point in code we dont know where we
are in xdoc
Next
Dickster

[Cerebrus]

Hi Dickster,

Is your question an answer to Neeraj's question ? Or is your question
separate from Neeraj's original question ?

The way I was thinking of solving Neeraj's problem was : (xDoc is the
XmlDocument)

1. Get a NodeList containing all Top level "menuItem" nodes, using
xDoc.SelectNode s("/menu/menuItem")
2. Iterate through this list, calling a method, say "ParseChildren( )"
3. The ParseChildren method will recursively process each child
"menuItem" node, using SelectSingleNod e(".//menuItem")
4. During processing, it creates an XmlDocumentFrag ment containing all
the OuterXml of the "menuItem" node.
5. It then creates a "subMenu" element just before this "menuItem"
node. Then the XmlDocumentFrag ment is appended as a child to this
"subMenu" element.
6. The original "menuItem" node is then deleted.
7. The loop moves on to the next sibling "menuItem" node, if no sibling
exists, it moves to the parent's next sibling.

I've got some of the code to work (uptill step 6), but I'm still stuck
at iterating through the siblings. Hopefully I'll find some time to
debug my code soon.

The XPath expression you presented selects only the first nested
"menuItem" element, since you have added the
not(preceding-sibling::menuIt em) part.

HTH,

Regards,

Cerebrus.

[neerajb]

Hi Cerebrus,
Thanks for the reply.
Your understandign perfectly correct.
The logic which we have to apply is we have to insert subMenu tag whenever
menuItem is having the child menuItem and all the child menuItem tags should
be enclosed in subMenu tag.
Like in my input xml menuItem "REPORTS" is having two child meuItems
Standard Reports and Custom Reports. so they should be come into "subMenu"
tag. Also Now Custom Reports is also having 5 menuItem childs, so they should
be enclosed in one SubMenu Tag.

It's very simple that Reports is top level Menu
Standard Reports and Custom Reports are second level menu
Child under Standard reports are third level menu

You can see in my output xml
Currently i am using the following logic but i am not sure will it work for
any level of nesting

please help in providing the bugproof logic.

For Each objMenuNode In objmenuItemNode List
If (checkChildMenu Items(objMenuNo de)) Then
Dim objSubMenuNode As System.Xml.XmlN ode =
objDoc.CreateNo de(System.Xml.X mlNodeType.Elem ent, "subMenu", "")
menuitems = menuItemsArrayL ist(objMenuNode )
For counter = 0 To menuitems.Count - 1

objSubMenuNode. AppendChild(Dir ectCast(menuite ms(counter), XmlNode))
Next
objMenuNode.App endChild(objSub MenuNode)
End If
Next

*************** *************** *************** *************** *************** *************** ***
Private Function checkChildMenuI tems(ByVal sampleNode As XmlNode) As Integer
Dim returnvalue As Boolean
Dim i As Integer
returnvalue = False
For i = 0 To sampleNode.Chil dNodes.Count - 1
If (sampleNode.Chi ldNodes(i).Name ) = "menuItem" Then
returnvalue = True
Exit For
End If
Next
checkChildMenuI tems = returnvalue
End Function

*************** *************** *************** *************** *************** *************** *****
Private Function menuItemsArrayL ist(ByVal sampleNode As XmlNode) As
ArrayList
Dim returnvalue As New ArrayList
Dim i As Integer
For i = 0 To sampleNode.Chil dNodes.Count - 1
If (sampleNode.Chi ldNodes(i).Name ) = "menuItem" Then
returnvalue.Add (sampleNode.Chi ldNodes(i))
End If
Next
menuItemsArrayL ist = returnvalue
End Function
"Cerebrus" wrote:

Hi,

I'm not sure I understand you correctly, but I think you need to insert
a <subMenu> element before each nested <menuItem> element. In other
words, you want to convert input.xml so that it looks like output.xml
???

Is that so ? If so, could you post whatever logic you have come up with
till now ?

Regards,

Cerebrus.

[neerajb]

Hi dickster,

Thanks for the reply.

Your Xpath is not giving the required nodes. it should give menuItem nodes
which are having menuItem Childs so that we can enclose them in subMenu tags.

like in case of input xml it should give REPORTS,Standar d Reports, Custom
Reports and HELP, so that we can include their menuitem tags in submenu tag.

"dickster" wrote:

I'm having trouble getting an Xpath Expression to pick out the relevant
nodes

e.g.
descendant::men uItem[parent::menuIte m][not(preceding-sibling::menuIt em)]

Cerebus - I Would like to see to insert a new parent node around the
relevant menuItem node after having got the relevant nodes in a
nodelist

i.e.

xdoc.Load("xpat h.xml")

Dim nl As XmlNodeList = xdoc.DocumentEl ement. _
SelectNodes("de scendant::menuI tem[parent::menuIte m][not(preceding-sibling::menuIt em)]")

For Each xnode In nl

txEle = xdoc.CreateElem ent("submenu")
txEle.AppendChi ld(xnode)

'Now how do we update xdoc
'replacing xnode with txEle
' because at this point in code we dont know where we
are in xdoc
Next
Dickster

[dickster]

Hi Cerebus, - thanks for your reply.

Neerajb - thanks for your reply & sorry for hopping in on the back of
your query.

I'm referring to Neeraj problem as it is an example of problem I would
like to see solved.

i.e. how to

1. take a list of child nodes (XmlNodeList) which match a particular
Xpath expression but are dotted randomly throughout an XML hierarchy
2. Imbed each of those child nodes in a parent node (eg. <subItem>)
back into the main XML message

I had not thought of using the OuterXML property of XmlDocumentFrag ment

Cerebus -I am very interested to see how you do step 4/5/6.

Indeed my XPath was wrong - but I would be interested to see an XPath
Expression which would pick out the exact list of nodes Neeraj needs
imbedded in a new <subItem> node. - I'm not sure if this is
possible.

Dickster

[dickster]

My point really is this...

When iterating through each node in an XMlNodeList how do you know
where you are in the document hierarchy, in order to do this kind of
insert

[Cerebrus]

Hi Neeraj,

After banging my head for quite a while, I've got it to work. It turns
out that the code isn't as beautiful as I would've liked, but frankly I
was fed up of Null Reference exceptions ~!!

Points to note :
---------------------
1. Copy and paste it into a Windows Form .vb file, and run Edit ->
Advanced -> Format Document. Don't try to view it here, since I have
removed all Tabs.
2. Add a Button named Button1 to your Form. This is needed only because
I start the processing at the click of the button.
3. I haven't used your code, since I had already progressed to some
extent with my own code, before your second post.
4. Hopefully, you can improve the code. I do hate repetitive code
statements, but in this case, it seemed necessary.
5. I have tried to comment inline, as much as possible, to allow you to
follow the program flow.
6. I have tested it with upto 5 levels of "menuItem" nesting.

=============== =============== ==
Imports System.Xml
Imports System.Xml.XPat h
:
:
Dim xDoc As XmlDocument
Dim xNode As XmlNode
Private Sub Form1_Load(ByVa l sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
xDoc = New XmlDocument()
xDoc.Load("Inpu t.xml")
End Sub

Private Sub Button1_Click(B yVal sender As System.Object, ByVal e As
System.EventArg s) Handles Button1.Click
Dim xList As XmlNodeList = xDoc.SelectNode s("/menu/menuItem")
Try
For Each xNode In xList
ParseChildren(x Node)
Next
xDoc.Save("Outp ut.xml")
MsgBox("Alright y, then...")
Catch ex As Exception
MsgBox(ex.Messa ge)
End Try
End Sub

Private Sub ParseChildren(B yVal theNode As XmlNode)
Dim menuItemNode, subMenuNode As XmlNode
'Don't bother trying Text nodes.
If theNode.NodeTyp e = XmlNodeType.Ele ment Then
If theNode.HasChil dNodes = True Then
menuItemNode = theNode.SelectS ingleNode("./menuItem")
'Proceed only if any nested menuItem elements are present.
If Not (menuItemNode Is Nothing) Then
'Add a new "subMenu" node
subMenuNode = xDoc.CreateElem ent("subMenu")
AddToSubMenu(me nuItemNode, theNode, subMenuNode)
'Repeat for any children menuItems
ParseChildren(s ubMenuNode.Firs tChild)

'No more children menuItems are present for this node,
'so continue with next sibling.
menuItemNode = subMenuNode.Nex tSibling
'Parse for any child menuItems of this sibling
ParseChildren(m enuItemNode)

While Not (menuItemNode Is Nothing)
AddToSubMenu(me nuItemNode, theNode, subMenuNode)
menuItemNode = subMenuNode.Nex tSibling
End While
End If
End If
End If
End Sub

Private Sub AddToSubMenu(By Val menuItemNode As XmlNode, ByVal
parentNode As XmlNode, ByVal SubMenuNode As XmlNode)
'Store the contents of this "menuItem" node in a DocFragment, including
the menuItem outer xml.
Dim frag As XmlDocumentFrag ment = xDoc.CreateDocu mentFragment()
frag.InnerXml = menuItemNode.Ou terXml
'Append contents of Frag.
SubMenuNode.App endChild(frag)
parentNode.Inse rtBefore(SubMen uNode, menuItemNode)
parentNode.Remo veChild(menuIte mNode)
End Sub
=============== =============== ==
Hope this helps,

Regards,

Cerebrus.

[Cerebrus]

Hi Dickster,

My point really is this...
When iterating through each node in an XMlNodeList how do you know
where you are in the document hierarchy, in order to do this kind of insert
My answer : We (or atleast I) don't.

I think you have posed a very profound question. I thought XPath can
select nodes, but I don't know if it can be used to
insert/delete/append nodes.

The XPath: descendant::men uItem[parent::menuIte m] will select all
"menuItem" elements in the document, which have a menuItem parent, as
you intended. Note that they may be at different levels of the
heirarchy. Inserting / Appending remains up to us. But as you correctly
realized, it seems quite a task to discover where the current
"menuItem" is in that heirarchy.
I had not thought of using the OuterXML property of XmlDocumentFrag ment
Cerebus -I am very interested to see how you do step 4/5/6.

Actually I have used the OuterXml property(ReadOn ly) of the "menuItem"
node and assigned it to the InnerXml property of the
XmlDocumentFrag ment.

For the steps, refer to my answer to Neeraj.

And lastly, it's Cerebrus...with an "r" ;-))

Regards,

Cerebrus.