Managing XPaths

Question

I deal with a lot of XML data in my job.  One constant requirement is to be able to manage XPath.  I may have an XML Document and need a particular node set in that document, then I might do a XPathSelectElements and need to acces the same node set, but my XPath has changed.  I may need to pass an XML Document from one namespace to another and need a common place to store (and share) the location of particular node sets within an XML Document.

One option I've tried is to create a static Global class to store my XPaths in.  But, if I have an XML document which I now have to iterate on using XPathSelectElements, then my XPath is no longer correct.

For example, if my XML document looks like

<root>
<sub1>
<sub2></sub2>
<sub2></sub2>
</sub1>
<sub1></sub1>
<sub1></sub1>
<sub1></sub1>
</root>

I can set a static Property in a static class "Global" called "xpSub2_a" to the value @"/root/sub1/sub2".  If, instead, I do

List<XElement> sub1set = xdoc.XPathSelectElements(@"/root/sub1");
foreach (XElement item in sub1set)
{
List<XElement> sub2sets = item.XPathSelectElements(Global.xpSub2_b);
}

Global.xpSub2_b would be equal to "sub2".

So, I end up with something that looks like

static Global
{
public string const xpSub2_b = "sub2";
public string const xpSub2_a = @"/root/sub1/sub2";
}

Is there a cleaner way to manage all of these XPath statements?

Answer 1

Currently I don't understand what the problem is. Do you want to store XPath expressions that you can combine, so that one path can be evaluated relative to a result found with another path? For your sample you would need the paths

  "/root/sub1"

and

  "sub2"

that way you could nest XPathSelectElements as you do in your C# sample.

Or you could concatenate the paths e.g.

  XPathSelectElements("/root/sub1" + "/" + "sub2")

to only use one call.

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MVP Data Platform Development My blog