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Retrieving optional nodes from an XmlDocument

Posted on 2004-10-27
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Last Modified: 2010-04-15
I have some Xml documents which i want to parse into C#, but they have many optional nodes that may or may not be there.
For example

<name><firstname>a</firstname><surname>b</surname></name>

or

<name><firstname>a</firstname><surname>c</surname><middlename>b</middlename></name>

How can i retrieve these single nodes quickly from Xml using c#?

I have been using .SelectSingleNode("//name/firstname") etc but these throw an exception if the node is not there.  Exceptions are pretty computationally expensive so i want to find a better way of finding out if a node exists in an xml document.

In summary, if i have an xml document which has lots of optional nodes, what is the best way to program my C# to use the values in these nodes if they exist.

Cheers
0
Question by:mt600
    2 Comments
     
    LVL 8

    Accepted Solution

    by:
    The easiest way to do is to check if the node is null after you select it:

    XmlNode node = xmlDoc.SelectSingleNode("//name/firstname");
    if(node != null)
       // The node exists, do something with it
    else
       // The node does not exist, do something else


    You could always loop through your complete XML using recursion, but it really depends on the situation if you need that.

    Cheers,

    Razzie
    0
     

    Author Comment

    by:mt600
    ok, thanks for your help.  It's good enough for me.

    0

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