How to handle XML anomalies!

[Bill Nguyen]

The following XML has an empty <UserDefinedT ag />
My VB.NET app got stuck here because I don't know how to handle it. It works
fine with a vlid user defined tag (next record)

<UserDefinedTag >40320121</UserDefinedTag>

Your help is greatly apprecited!!

Bill

- <JACOData>
- <Inventorys>
- <Inventory Type="Physical" >
<Product>Dyed Diesel</Product>
<TankNumber>150 08230383-1</TankNumber>
<UserDefinedT ag />
<DateTime>1/14/2007 1:00:49 PM</DateTime>
<Volume>308.122 </Volume>
<Ullage>2674.88 </Ullage>
<Height>12</Height>
<WaterHeight>3. 4</WaterHeight>
<DaystoEmpty> 1</DaystoEmpty>
</Inventory>

- <Inventory Type="Physical" >
<Product>Clea r Diesel</Product>
<TankNumber>150 08230411-1</TankNumber>
<UserDefinedTag >40320121</UserDefinedTag>
<DateTime>1/14/2007 12:00:49 PM</DateTime>
<Volume>308.122 </Volume>
<Ullage>5805.88 </Ullage>
<Height>12</Height>
<WaterHeight>-9.44</WaterHeight>
<DaystoEmpty> 0</DaystoEmpty>
</Inventory>
- </Inventory>
</Inventorys>
</JACOData>

[Martin Honnen]

Bill Nguyen wrote:

The following XML has an empty <UserDefinedT ag />
My VB.NET app got stuck here because I don't know how to handle it. It works
fine with a vlid user defined tag (next record)

<UserDefinedTag >40320121</UserDefinedTag>

Well what exactly does your app with that XML? What goes wrong, do you
get a runtime error? How exactly does your code look?

An empty element is perfectly well-formed XML so the XML parser should
not give any problems.
--

Martin Honnen --- MVP XML
http://JavaScript.FAQTs.com/

[Bill Nguyen]

Martin;
The problem is that it doesn't throw any error!
I only want to detect if an element is empty.

Here's the code:

DS.ReadXml(mXML file)

Dim xRow As DataRow

Dim malternateID, mDaystoEmpty As Integer

For i = 0 To DS.Tables(1).Ro ws.Count - 1

malternateID = 0

If IsDBNull(DS.Tab les(1).Rows(i). Item("UserDefin edTag")) = False Then

malternateID = DS.Tables(1).Ro ws(i).Item("Use rDefinedTag")

Else

MsgBox("invalid altID!: " & mtankID)

End If

Thanks

Bill

"Martin Honnen" <ma*******@yaho o.dewrote in message
news:Ov******** ******@TK2MSFTN GP03.phx.gbl...

Bill Nguyen wrote:

>The following XML has an empty <UserDefinedT ag />
My VB.NET app got stuck here because I don't know how to handle it. It
works fine with a vlid user defined tag (next record)

<UserDefinedTag >40320121</UserDefinedTag>

Well what exactly does your app with that XML? What goes wrong, do you get
a runtime error? How exactly does your code look?

An empty element is perfectly well-formed XML so the XML parser should not
give any problems.
--

Martin Honnen --- MVP XML
http://JavaScript.FAQTs.com/

[Martin Honnen]

Bill Nguyen wrote:

The problem is that it doesn't throw any error!
I only want to detect if an element is empty.

Do you have a schema associated with the XML? An empty element is not an
error in terms of XML and for instance if the type of the element is
xs:string then in case of the empty element the element is not null but
rather contains the emtpy string.
What you can do is use xsi:nil as a special attribute in XML markup e.g.
<UserDefinedT ag xmlns:xsi="http ://www.w3.org/2001/XMLSchema-instance"
xsi:nil="true"/>
but then the schema needs to defined that the element is nillable.


--

Martin Honnen --- MVP XML
http://JavaScript.FAQTs.com/