XElement, XAttribute Default Values

[Rory Becker]

Is there a way to do something like the following...

 

[Rory Becker]

-------------------------------------------------------------

Dim x As String =
SomeXElement.<Element1>.<SubElement>[email protected]("So
meDefaultString")
-------------------------------------------------------------

It seems that the @SomeAttribute does not resolve to an XAttribute but to
a string which was unexpected.

So I guess I can Throw and Extension method on String and use that ?

 

[Martin Honnen]

Is there a way to do something like the following...

You could use If(@att, "default")
e.g. this sample

Dim foo As XElement = <foo>
<bar att="value"/>
<baz/>
</foo>
Dim val1 As String = If(foo.<bar>.@att, "default 1")
Dim val2 As String = If(foo.<baz>.@att, "default 2")
Console.WriteLine("val1: {0}; val2: {1}", val1, val2)

outputs

val1: value; val2: default 2

 

[Steven Cheng [MSFT]]

Hi Rory,

I agree with Martin that you can first get the value via LINQ expression,
and then use iif expression to check the value.


=========================
Dim xml As XElement = _
<foo><bar
attr1="value1">fdsfdsf<block>dfdsf</block></bar></foo>

Dim str1 As String = xml.<bar>[email protected]()
Console.WriteLine(IIf(String.IsNullOrEmpty(str1), "default value",
str1))
========================

Sincerely,

Steven Cheng

Microsoft MSDN Online Support Lead


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--------------------

 

[Rory Becker]

Hello Martin,

You could use If(@att, "default")
e.g. this sample
Dim foo As XElement = <foo>
<bar att="value"/>
<baz/>
</foo>
Dim val1 As String = If(foo.<bar>.@att, "default 1")
Dim val2 As String = If(foo.<baz>.@att, "default 2")
Console.WriteLine("val1: {0}; val2: {1}", val1, val2)
outputs

val1: value; val2: default 2

Sorry for the delayed reply.

Wow.... I had heard and indeed used the new If syntax ( with 3 params) to
replace iif but I had no Idea of the version with only 2 params.

Damn that's going to be useful.

Thanks very much