Cannot get element by attribute value with XDocument - vb.net

Question

I've got customUIXml object of type XDocument and it has the following XML as value:
<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui" onLoad="Ribbon_Load">
<ribbon>
<tabs>
<tab id="t1" label="Shalala">
<!-- stuff -->
</tab>
<tab id="tab_dev" label="SomeOtherTab">
<!-- stuff -->
</tab>
<tab id="t108" label="MyTab">
<!-- stuff -->
</tab>
</tabs>
</ribbon>
</customUI>
and I want to get the tab node with label value "MyTab". This is the code I use:
Dim xtab As XElement = Nothing
Dim nodes = From nodeToTake In customUIXml.Descendants().Elements("tab") _
Where nodeToTake.Attribute("label").Value = "MyTab"
Select nodeToTake
For Each tab As XElement In nodes
xtab = tab
Next
But I get no results and I can't seem to find what am I doing wrong...

Answer 1

You could simply use XML literals, so your code would be as easy as:
Dim xtab = customUIXml.<ribbon>.<tabs>.<tab>.First(Function(tab) tab.#label = "MyTab")
Also, your code seems to work, so your problem seems to be elsewhere.
Dim customUIXml = <customUI>
<ribbon>
<tabs>
<tab id="t1" label="Shalala">
<!-- stuff -->
</tab>
<tab id="tab_dev" label="SomeOtherTab">
<!-- stuff -->
</tab>
<tab id="t108" label="MyTab">
<!-- stuff -->
</tab>
</tabs>
</ribbon>
</customUI>
Dim xtab As XElement = Nothing
Dim nodes = From nodeToTake In customUIXml.Descendants().Elements("tab") _
Where nodeToTake.Attribute("label").Value = "MyTab"
Select nodeToTake
For Each tab As XElement In nodes
xtab = tab
Next
Console.WriteLine(xtab)
displays
<tab id="t108" label="MyTab">
<!-- stuff -->
</tab>
just fine.
If your actual XML contains a namespace, you have to take that into account:
...
Dim df As XNamespace = customUIXml.Name.Namespace
Dim xtab As XElement = Nothing
Dim nodes = From nodeToTake In customUIXml.Descendants().Elements(df + "tab") _
...

Answer 2

string xml = "<customUI xmlns='http://schemas.microsoft.com/office/2009/07/customui' onLoad='Ribbon_Load'><ribbon><tabs><tab id='t1' label='Shalala'><!-- stuff --></tab><tab id='tab_dev' label='SomeOtherTab'><!-- stuff --></tab><tab id='t108' label='MyTab'><!-- stuff --></tab></tabs></ribbon></customUI>";
var xelement = XElement.Parse(xml);
var list = xelement.Descendants().Where(x => x.Name.LocalName == "tab" && x.Attribute("label") != null).ToList();
list.ForEach(x => Console.WriteLine(x.Attribute("label").Value));
you can access localName to check the elment tag value ,
Checked with LinqPad and it works expectedly hope that helps..
:)
Edit : Vb code from Telerik convert :
Dim xml As String = "<customUI xmlns='http://schemas.microsoft.com/office/2009/07/customui' onLoad='Ribbon_Load'><ribbon><tabs><tab id='t1' label='Shalala'><!-- stuff --></tab><tab id='tab_dev' label='SomeOtherTab'><!-- stuff --></tab><tab id='t108' label='MyTab'><!-- stuff --></tab></tabs></ribbon></customUI>"
Dim xelement__1 = XElement.Parse(xml)
Dim list = xelement__1.Descendants().Where(Function(x) x.Name.LocalName = "tab" AndAlso x.Attribute("label") IsNot Nothing).ToList()
list.ForEach(Function(x) Console.WriteLine(x.Attribute("label").Value))