I have been just about managing to manipulate XML in VB.net but I've run into a problem I'm really struggling with, so I'm reaching out for a little guidance please?!
With this example XML...
<?xml version="1.0" encoding="utf-8"?>
<dataset>
<packages>
<package index="1">
<desc>First Package</desc>
<rmabool>1</rmabool>
<rmaref>RMACASE1</rmaref>
<bootfiles>1</bootfiles>
<image>1</image>
<driver>3</driver>
<driver>4</driver>
</package>
<package index="2">
<desc>Second Package</desc>
<bootfiles>2</bootfiles>
<image>2</image>
<driver>3</driver>
</package>
<package index="3">
<desc>Third Package</desc>
<bootfiles>3</bootfiles>
<image>2</image>
<driver>3</driver>
</package>
</packages>
</dataset>
...I would like to count how many elements, named 'driver', are contained in an element named 'package' with an index matching "1". I would expect the result to be returned is "2", or if I change the search to match index with "3" then I would expect the result is "1".
Elsewhere I have a simple sub which returns a count of elements only matching a name, below is my effort to modify this but I cannot get it to work...
Public Function CountElementDescendents(ByVal CFGFile As String,_ 'Path to Config.xml
ByVal Parent As String,_ 'Name of element to search descendents eg. 'package'
ByVal ParentIndex As String,_ 'Index value of element to search descendents eg. '1'
ByVal ElementCount As String_ 'Name of descendent elements to count 'eg. 'driver'
) As Integer 'Return number of matching elements eg. '2'
Dim ReturnValue As Integer = 0
Dim Xe As XElement
Xe = XElement.Load(CFGFile)
Dim Query As IEnumerable(Of XElement) = Xe.Elements(Parent).Attribute("index="&ParentIndex).Descendants(ElementCount)
ReturnValue = Query.Count()
CountElementDescendents = ReturnValue
End Function
I'm not sure if this is possible or even if I have taken the best approach of structuring my XML, can someone offer some assistance or advice please? Thanks!
Thanks to @dbasnett and @Craig for their help, you're awesome! I'll mark this as answered.
Give this a try. The LINQ query examines all driver elements and selects those whose parent is a package with an index of 1.
'for testing use XML literal
Dim xe As XElement
xe = <dataset>
<packages>
<package index="1">
<desc>First Package</desc>
<rmabool>1</rmabool>
<rmaref>RMACASE1</rmaref>
<bootfiles>1</bootfiles>
<image>1</image>
<driver>3</driver>
<driver>4</driver>
</package>
<package index="2">
<desc>Second Package</desc>
<bootfiles>2</bootfiles>
<image>2</image>
<driver>3</driver>
</package>
<package index="3">
<desc>Third Package</desc>
<bootfiles>3</bootfiles>
<image>2</image>
<driver>3</driver>
</package>
</packages>
</dataset>
' I would like to count how many elements, named 'driver',
' are contained in an element named 'package' with an index matching "1".
'
Dim ie As IEnumerable(Of XElement)
ie = From el In xe...<driver>
Where el.Parent.Name.LocalName = "package" AndAlso el.Parent.@index = "1"
Select el
edit: As function
Private Function Srch(ElementToSearch As XElement,
ParentName As String,
ParentIndex As String) As IEnumerable(Of XElement)
Dim ie As IEnumerable(Of XElement)
ie = From el In ElementToSearch...<driver>
Where el.Parent.Name.LocalName = ParentName AndAlso el.Parent.@index = ParentIndex
Select el
Return ie
End Function
edit 2 - updated function
Private Function Srch(ElementToSearch As XElement,
FindThis As String,
ParentName As String,
ParentIndex As String) As IEnumerable(Of XElement)
Dim ie As IEnumerable(Of XElement)
ie = From el In ElementToSearch.Descendants(FindThis)
Where el.Parent.Name.LocalName = ParentName AndAlso el.Parent.@index = ParentIndex
Select el
Return ie
End Function
Tested with
Dim rslts As IEnumerable(Of XElement)
rslts = Srch(xe, "bootfiles", "package", "1")