Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

What is wrong with my attempt to read an xml file using xPath expressions (C#)

Posted on 2014-10-21
9
Medium Priority
?
239 Views
Last Modified: 2014-10-22
I am trying to use this code to get to the Order elements in an xml file:

                    IEnumerable<XElement> nodeList = xDoc.XPathSelectElements("//Orders/Order");

I have used this technique before but can't find what I'm doing wrong on this particular one:

The xml file looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<Orders xmlns="http://www.junk.com/xml/mp/order/R1.1" xmlns:xsi="http://junk/2001/XMLSchema-instance" xsi:schemaLocation="http://www.junk.com/xml/mp/order/R1.1 http://support.junk.com/mp/R1.1/order/Orders.xsd">
    <Order>
        <OrderID>100000009</OrderID>
            (and all sorts of child elements)
    </Order>
    <Order>
        <OrderID>1000000111</OrderID>
            (and all sorts of child elements)
    </Order>
</Orders>
0
Comment
Question by:g_johnson
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 5
  • 4
9 Comments
 
LVL 4

Author Comment

by:g_johnson
ID: 40395473
I found that this technique works if I strip out everything and the element looks like this:
<Orders>

I then can read it like this:  xDoc.XPathSelectElements("/Order");

However, in reality I can't strip that out.

How do I get around this?

Thanks,
0
 
LVL 34

Expert Comment

by:it_saige
ID: 40395710
Try this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml;
using System.Xml.Linq;
using System.Xml.XPath;

static class XmlExample
{
	public static void Main()
	{
		XmlReader reader = XmlReader.Create("Orders.xml");
		XElement data = XElement.Load(reader);
		XmlNameTable table = reader.NameTable;
		XmlNamespaceManager manager = new XmlNamespaceManager(table);
		manager.AddNamespace("ns", "http://www.junk.com/xml/mp/order/R1.1");
		foreach (XElement order in data.XPathSelectElements("./ns:Order", manager))
		{
			foreach (var pair in (from id in order.Elements() where id.Name.LocalName.Contains("OrderID") select new { id.Name.LocalName, id.Value }))
				Console.WriteLine(string.Format("Name - {0}; Value - {1}", pair.LocalName, pair.Value));
		}
		Console.ReadLine();
	}
}

Open in new window

Orders.xml:
<?xml version="1.0" encoding="UTF-8"?>
<Orders xmlns="http://www.junk.com/xml/mp/order/R1.1" xmlns:xsi="http://junk/2001/XMLSchema-instance" xsi:schemaLocation="http://www.junk.com/xml/mp/order/R1.1 http://support.junk.com/mp/R1.1/order/Orders.xsd">
	<Order>
		<OrderID>100000009</OrderID>
	</Order>
	<Order>
		<OrderID>1000000111</OrderID>
	</Order>
</Orders>

Open in new window

Produces the following output:Capture.JPG
-saige-
0
 
LVL 4

Author Comment

by:g_johnson
ID: 40397343
I can certainly try this, but I'm wondering why the xPath technique does not work if there is a namespace in the element.
0
Quick Start: DOCKER

Sometimes you just need a Quick Start on a topic in order to begin using it.. this is just what you need to know to get up and running with Docker!

 
LVL 34

Expert Comment

by:it_saige
ID: 40397451
If you compare the Node Name between the Namespace version and non-Namespace version, you will find that when you declare a namespace that the Node Name is equal to the {Namespace} + XML Element Name; e.g. -Capture.JPGVersus the non-Namespace version, where the Node Name is equal to the XML Element Name; e.g. -Capture.JPG
-saige-
0
 
LVL 4

Author Comment

by:g_johnson
ID: 40397744
Thanks.  I understand that now, I think.

I combined that info with some other stuff I found in my research, and now this code runs without error but doesn't identify the nodes:

                    XDocument xDoc = XDocument.Load(XMLFileName);

                    XmlNamespaceManager oManager = new XmlNamespaceManager(new NameTable());
                    oManager.AddNamespace("ns", "{http://www.junk.com/xml/mp/order/R1.1}");
                    IEnumerable<XElement> nodeList = xDoc.XPathSelectElements("/ns:Orders/ns:Order",oManager);

Does this have anything to do with it having multiple namespaces in the Orders element?  Or is there something else I'm doing wrong?
0
 
LVL 34

Expert Comment

by:it_saige
ID: 40397918
Remove the brackets from around your namespace definition.

-saige-
0
 
LVL 34

Accepted Solution

by:
it_saige earned 2000 total points
ID: 40397950
In other words; this line -
oManager.AddNamespace("ns", "{http://www.junk.com/xml/mp/order/R1.1}");

Open in new window

Should be entered this way -
oManager.AddNamespace("ns", "http://www.junk.com/xml/mp/order/R1.1");

Open in new window


-saige-
0
 
LVL 34

Expert Comment

by:it_saige
ID: 40397966
Making your modifications to the above code -
using System;
using System.Linq;
using System.Xml;
using System.Xml.Linq;
using System.Xml.XPath;

static class XmlExample
{
	public static void Main()
	{
		XDocument document = XDocument.Load("Orders.xml");
		XmlNamespaceManager manager = new XmlNamespaceManager(new NameTable());
		manager.AddNamespace("ns", "http://www.junk.com/xml/mp/order/R1.1");

		foreach (XElement order in document.XPathSelectElements("/ns:Orders/ns:Order", manager))
		{
			foreach (var pair in (from id in order.Elements() where id.Name.LocalName.Contains("OrderID") select new { id.Name.LocalName, id.Value }))
				Console.WriteLine(string.Format("Name - {0}; Value - {1}", pair.LocalName, pair.Value));
		} 
		Console.ReadLine();
	}
}

Open in new window

Produces the following output -Capture.JPG
-saige-
0
 
LVL 4

Author Closing Comment

by:g_johnson
ID: 40398029
Thank you.  You've been very helpful!
0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
It was really hard time for me to get the understanding of Delegates in C#. I went through many websites and articles but I found them very clumsy. After going through those sites, I noted down the points in a easy way so here I am sharing that unde…
This tutorial will teach you the special effect of super speed similar to the fictional character Wally West aka "The Flash" After Shake : http://www.videocopilot.net/presets/after_shake/ All lightning effects with instructions : http://www.mediaf…
In this video, Percona Solution Engineer Dimitri Vanoverbeke discusses why you want to use at least three nodes in a database cluster. To discuss how Percona Consulting can help with your design and architecture needs for your database and infras…

705 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question