Sorting XML nodes based on DateTime attribute C#, XPath

Question

I have a XML Structure that looks like this.

<sales>
  <item name="Games" sku="MIC28306200" iCat="28" 
     sTime="11/26/2008 8:41:12 AM" 
     price="1.00" desc="Item Name" />
  <item name="Games" sku="MIC28307100" iCat="28" 
     sTime="11/26/2008 8:42:12 AM" 
     price="1.00" desc="Item Name" />
...
</sales>

I am trying to find a way to SORT the nodes based on the sTime attribute which is a DateTime.ToString() value. The trick is I need to keep the Nodes in tact and for some reason I can't find a way to do that. I'm fairly certain that LINQ and XPath have a way to do it, but I'm stuck because I can't seem to sort based on DateTime.ToString() value.

XPathDocument saleResults = new XPathDocument(@"temp/salesData.xml");
XPathNavigator navigator = saleResults.CreateNavigator();

XPathExpression selectExpression = navigator.Compile("sales/item/@sTime");
selectExpression.AddSort("@sTime", 
    XmlSortOrder.Descending, 
    XmlCaseOrder.None, 
    "", 
    XmlDataType.Number);

XPathNodeIterator nodeIterator = navigator.Select(selectExpression);

while( nodeIterator.MoveNext() )
    {
         string checkMe = nodeIterator.Current.Value;
    }

I also need to maintain a pointer to the NODE to retrieve the values of the other attributes.

Perhaps this isn't a simple as I thought it would be.

Thanks.

Solution: Here's what I ended up using. Taking the selected answer and the IComparable class this is how I get the XML nodes sorted based on the sTime attribute and then get the all the attributes into the appropriate Arrays to be used later.

    XPathDocument saleResults = new XPathDocument(@"temp/salesData.xml");
    XPathNavigator navigator = saleResults.CreateNavigator();
    XPathExpression selectExpression = navigator.Compile("sales/item");
    XPathExpression sortExpr = navigator.Compile("@sTime");
    selectExpression.AddSort(sortExpr, new DateTimeComparer());
    XPathNodeIterator nodeIterator = navigator.Select(selectExpression);
    int i = 0;
    while (nodeIterator.MoveNext())
       {
          if (nodeIterator.Current.MoveToFirstAttribute())
          {
              _iNameList.SetValue(nodeIterator.Current.Value, i);
          }
          if (nodeIterator.Current.MoveToNextAttribute())
          {
              _iSkuList.SetValue(nodeIterator.Current.Value, i);
          }
          ...
          nodeIterator.Current.MoveToParent();
          i++;

      }

Answer 1

There's an overload of XPathExpression.Addsort which takes an IComparer interface. If you implement the comparison yourself as IComparer, you could use this mechanism.

 class Program
        {
            static void Main(string[] args)
            {
                XPathDocument saleResults = new XPathDocument( @"salesData.xml" );
                XPathNavigator navigator = saleResults.CreateNavigator( );
                XPathExpression selectExpression = navigator.Compile( "sales/item" );
                XPathExpression sortExpr = navigator.Compile("@sTime");
                selectExpression.AddSort(sortExpr, new DateTimeComparer());
                XPathNodeIterator nodeIterator = navigator.Select( selectExpression );            
                while ( nodeIterator.MoveNext( ) )
                {
                    string checkMe = nodeIterator.Current.Value;
                }
            }
            public class DateTimeComparer : IComparer
            {
                public int Compare(object x, object y)
                {
                    DateTime dt1 = DateTime.Parse( x.ToString( ) );
                    DateTime dt2 = DateTime.Parse( y.ToString( ) );
                    return dt1.CompareTo( dt2 );
                }
            }
        }

Answer 2

Here you go:

XmlDocument myDoc = new XmlDocument();

myDoc.LoadXml(@"
<sales>
<item name=""Games""
    sku=""MIC28306200""
    iCat=""28""
    sTime=""11/26/2008 8:41:12 AM""
    price=""1.00""
    desc=""Item Name"" />
<item name=""Games""
    sku=""MIC28307100""
    iCat=""28""
    sTime=""11/26/2008 8:42:12 AM""
    price=""1.00""
    desc=""Item Name"" />
</sales>
");

var sortedItems = myDoc.GetElementsByTagName("item").OfType<XmlElement>()
    .OrderBy(item => DateTime.ParseExact(item.GetAttribute("sTime"), "MM/dd/yyyy h:mm:ss tt", null));

foreach (var item in sortedItems)
{
    Console.WriteLine(item.OuterXml);
}

That's a Console app that works perfectly.

Answer 3

What you're trying to do is accomplished a lot more easily if the XML is properly constructed. The XML Schema recommendation says that date/time values should be represented in ISO8601 format, i.e. CCCC-MM-DD HH:MM:SS. (Actually XML Schema wants the separator between date and time to be a T, and at the moment I don't remember why.)

The two principal advantages of formatting dates and times this way are:

• That's what other users of XML expect, and
• You can sort on their string values.

It's a cruelty to format dates any other way in XML that's going to be processed by XSLT.

It's easy enough to make .NET emit DateTime values in this format (use the "s" format specifier, which stands for - wait for it - "sortable").

Answer 4

Here is an XSLT solution:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

    <xsl:template match="sales">
      <sales>
        <xsl:for-each select="item">
          <xsl:sort select="substring(@sTime,7,4)" data-type="number"/>
          <xsl:sort select="substring(@sTime,1,2)" data-type="number"/>
          <xsl:sort select="substring(@sTime,4,2)" data-type="number"/>
          <xsl:sort select="substring-after(substring-after(@sTime,' '),' ')" />
          <xsl:sort data-type="number" select=
           "translate(
               substring-before(substring-after(@sTime,' '),' '),
               ':', ''
                      )
               " />
          <xsl:copy-of select="."/>
        </xsl:for-each>
      </sales>
    </xsl:template>
</xsl:stylesheet>

When this transformation is applied on the following XML document:

<sales>
    <item name="Games" sku="MIC28306200" iCat="28"
          sTime="11/26/2008 8:41:12 PM"
          price="1.00" desc="Item Name" />
    <item name="Games" sku="MIC28307100" iCat="28"
          sTime="11/26/2008 8:42:12 AM"
                price="1.00" desc="Item Name" />
    <item name="Games" sku="MIC28307100" iCat="28"
          sTime="11/26/2008 11:42:12 AM"
                price="1.00" desc="Item Name" />
    <item name="Games" sku="MIC28306200" iCat="28"
          sTime="12/23/2008 8:41:12 PM"
          price="1.00" desc="Item Name" />
    <item name="Games" sku="MIC28307100" iCat="28"
          sTime="12/23/2008 8:42:12 AM"
                price="1.00" desc="Item Name" />
</sales>

the correct result is produced:

<sales>
   <item name="Games" sku="MIC28307100" iCat="28" sTime="11/26/2008 8:42:12 AM" price="1.00" desc="Item Name"/>
   <item name="Games" sku="MIC28307100" iCat="28" sTime="11/26/2008 11:42:12 AM" price="1.00" desc="Item Name"/>
   <item name="Games" sku="MIC28306200" iCat="28" sTime="11/26/2008 8:41:12 PM" price="1.00" desc="Item Name"/>
   <item name="Games" sku="MIC28307100" iCat="28" sTime="12/23/2008 8:42:12 AM" price="1.00" desc="Item Name"/>
   <item name="Games" sku="MIC28306200" iCat="28" sTime="12/23/2008 8:41:12 PM" price="1.00" desc="Item Name"/>
</sales>

Answer 5

@Timothy Khouri: Know it's an old post but I can't manage to make your code working... (Simply copied and pasted) The problem is in : OfType I got an error that says Sysyem.Xml.XmlNodeList doesn't have an "OfType" method... What's wrong? Can you tell me please?

BTW

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Xml;
using System.Xml.XPath;
using System.IO;

Answer 6

suppose ur date time is in this format

2010-06-01T15:16:29+05:00

then simplest way that can be done is

< xsl:sort select="translate(XPATH_RETURNING_DATE,'-T:+','')" order="descending" data-type="number" />

IN DATETIME JUST REPLACE EXTRA CHARACTERS in my datetime format i have the extra characters ( - T : and + ) so just replace it AND THEN YOUR DATE TIME WILL BE IN NUMBER FORMAT THAT CAN BE SORTED EASILY

Answer 7

check a similar example on http://www.easytipsandtricks.com/browse/sort-xml-by-date-using-xslt

it worked great for me.

cheers, aditya

Answer 8

what if my xml nodes are nested then how to do that.

XML example :

Tree AllowNodeEditing="True" OnClientContextMenuItemClicking="onClientContextMenuItemClicking" Skin="Web20" EnableAjaxSkinRendering="False" Width="410px" sort="ascending">

Answer 9

this is working fine with given examoples but when i inserted a node as a child of a node then its is not working it is only sorting at first level i wanted to sort upto the child level pls help

Answer 10

hi pls help me to sort with this XML file.