如何找到当前节点（n）和先前节点（n-1）的差异

Question

Would you please help and advice on how to insert a node into my XML file, whereby this node will have the inner value of : difference between current node and previous node (just one previous data).

My input XML is:

    <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
    <Root>
      <Test>
        <TestPhase>1</TestPhase>
        <TestFlow>1</TestFlow>
        <TestParameter>1</TestParameter>
        <OriIndex>0</OriIndex>
      </Test>
      <Test>
        <TestPhase>1</TestPhase>
        <TestFlow>1</TestFlow>
        <TestParameter>2</TestParameter>
        <OriIndex>1</OriIndex>
      </Test>
      <Test>
        <TestPhase>1</TestPhase>
        <TestFlow>3</TestFlow>
        <TestParameter>1</TestParameter>
        <OriIndex>2</OriIndex>
      </Test>
      <Test>
        <TestPhase>1</TestPhase>
        <TestFlow>2</TestFlow>
        <TestParameter>2</TestParameter>
        <OriIndex>3</OriIndex>
      </Test>
      <Test>
        <TestPhase>2</TestPhase>
        <TestFlow>1</TestFlow>
        <TestParameter>1</TestParameter>
        <OriIndex>4</OriIndex>
      </Test>
.
.
.
.
.

My XSLT is :

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">

<xsl:output method="xml" encoding = "UTF-8" indent="yes" omit-xml-declaration="no" standalone="yes" />


  <xsl:template match="Root">
   <xsl:copy>
    <xsl:apply-templates select="Test">
      <xsl:sort select="TestPhase" data-type="number" order="ascending"/>
      <xsl:sort select="TestFlow" data-type="number" order="ascending"/>
      <xsl:sort select="TestParameter" data-type="number" order="ascending"/>
    </xsl:apply-templates>
   </xsl:copy>
  </xsl:template>


  <xsl:template match="@* | node()">
    <xsl:copy>
          <xsl:apply-templates select="@* | node()"/>
    </xsl:copy>
  </xsl:template>


   <xsl:template match="Test">
     <xsl:copy>
       <xsl:apply-templates select="@* | *"/> 
       <SortedIndex><xsl:value-of select="position() - 1"/></SortedIndex>
       <DiffSortedIndex><xsl:value-of select="position() - 1 - OriIndex" /></DiffSortedIndex>
       <DiffOriIndex><xsl:value-of select="OriIndex - preceding-sibling::Test[position()-1]/OriIndex" /></DiffOriIndex>
     </xsl:copy>
   </xsl:template>


</xsl:stylesheet>

My output XML is :

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<Root>
  <Test>
    <TestPhase>1</TestPhase>
    <TestFlow>1</TestFlow>
    <TestParameter>1</TestParameter>
    <OriIndex>0</OriIndex>
    <SortedIndex>0</SortedIndex>
    <DiffSortedIndex>0</DiffSortedIndex>
    <DiffOriIndex>NaN</DiffOriIndex>
  </Test>
  <Test>
    <TestPhase>1</TestPhase>
    <TestFlow>1</TestFlow>
    <TestParameter>2</TestParameter>
    <OriIndex>1</OriIndex>
    <SortedIndex>1</SortedIndex>
    <DiffSortedIndex>0</DiffSortedIndex>
    <DiffOriIndex>NaN</DiffOriIndex>
  </Test>
  <Test>
    <TestPhase>1</TestPhase>
    <TestFlow>2</TestFlow>
    <TestParameter>2</TestParameter>
    <OriIndex>3</OriIndex>
    <SortedIndex>2</SortedIndex>
    <DiffSortedIndex>-1</DiffSortedIndex>
    <DiffOriIndex>NaN</DiffOriIndex>
  </Test>
  <Test>
    <TestPhase>1</TestPhase>
    <TestFlow>2</TestFlow>
    <TestParameter>2</TestParameter>
    <OriIndex>12</OriIndex>
    <SortedIndex>3</SortedIndex>
    <DiffSortedIndex>-9</DiffSortedIndex>
    <DiffOriIndex>NaN</DiffOriIndex>
  </Test>
.
.
.
.
.

My Expected output is :

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<Root>
  <Test>
    <TestPhase>1</TestPhase>
    <TestFlow>1</TestFlow>
    <TestParameter>1</TestParameter>
    <OriIndex>0</OriIndex>
    <SortedIndex>0</SortedIndex>
    <DiffSortedIndex>0</DiffSortedIndex>
    <DiffOriIndex>NaN</DiffOriIndex>
  </Test>
  <Test>
    <TestPhase>1</TestPhase>
    <TestFlow>1</TestFlow>
    <TestParameter>2</TestParameter>
    <OriIndex>1</OriIndex>
    <SortedIndex>1</SortedIndex>
    <DiffSortedIndex>0</DiffSortedIndex>
    <DiffOriIndex>1</DiffOriIndex>
  </Test>
  <Test>
    <TestPhase>1</TestPhase>
    <TestFlow>2</TestFlow>
    <TestParameter>2</TestParameter>
    <OriIndex>3</OriIndex>
    <SortedIndex>2</SortedIndex>
    <DiffSortedIndex>-1</DiffSortedIndex>
    <DiffOriIndex>2</DiffOriIndex>
  </Test>
  <Test>
    <TestPhase>1</TestPhase>
    <TestFlow>2</TestFlow>
    <TestParameter>2</TestParameter>
    <OriIndex>12</OriIndex>
    <SortedIndex>3</SortedIndex>
    <DiffSortedIndex>-9</DiffSortedIndex>
    <DiffOriIndex>9</DiffOriIndex>
  </Test>
  <Test>
    <TestPhase>1</TestPhase>
    <TestFlow>3</TestFlow>
    <TestParameter>1</TestParameter>
    <OriIndex>2</OriIndex>
    <SortedIndex>4</SortedIndex>
    <DiffSortedIndex>2</DiffSortedIndex>
    <DiffOriIndex>-10</DiffOriIndex>
  </Test>
  <Test>
    <TestPhase>2</TestPhase>
    <TestFlow>1</TestFlow>
    <TestParameter>1</TestParameter>
    <OriIndex>4</OriIndex>
    <SortedIndex>5</SortedIndex>
    <DiffSortedIndex>1</DiffSortedIndex>
    <DiffOriIndex>2</DiffOriIndex>
  </Test>
  <Test>
    <TestPhase>2</TestPhase>
    <TestFlow>1</TestFlow>
    <TestParameter>2</TestParameter>
    <OriIndex>5</OriIndex>
    <SortedIndex>6</SortedIndex>
    <DiffSortedIndex>1</DiffSortedIndex>
    <DiffOriIndex>1</DiffOriIndex>
  </Test>
  <Test>
    <TestPhase>2</TestPhase>
    <TestFlow>2</TestFlow>
    <TestParameter>1</TestParameter>
    <OriIndex>6</OriIndex>
    <SortedIndex>7</SortedIndex>
    <DiffSortedIndex>1</DiffSortedIndex>
    <DiffOriIndex>1</DiffOriIndex>
  </Test>
  <Test>
    <TestPhase>2</TestPhase>
    <TestFlow>2</TestFlow>
    <TestParameter>2</TestParameter>
    <OriIndex>7</OriIndex>
    <SortedIndex>8</SortedIndex>
    <DiffSortedIndex>1</DiffSortedIndex>
    <DiffOriIndex>1</DiffOriIndex>
  </Test>
.
.
.
.
.

I am not able to get the 1 part correct. The expected inner value = OriIndex (present position) - OriIndex (previous position) or OriIndex (position n) - OriIndex (position n-1).

Please help me on this. Your effort is very much appreciated.

Thank you very much.

Cheers!

Answer 1

I used xml linq. You expected output isn't using the same xml as your input xml so my results aren't matching yours. I think my code is right.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;

namespace ConsoleApplication1
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            XDocument doc = XDocument.Load(FILENAME);

            List<XElement> tests = doc.Descendants("Test").OrderBy(x => (int)x.Element("OriIndex")).ToList();

            int previousOriIndex = 0;
            for (int i = 0; i < tests.Count; i++)
            {
                XElement test = tests[i];
                int currentOriIndex = (int)test.Element("OriIndex");
                test.Add(new XElement("SortedIndex", i));
                test.Add(new XElement("DiffSortedIndex", i - currentOriIndex));

                if (i == 0)
                {
                    test.Add(new XElement("DiffOriIndex", "NaN"));
                }
                else
                {
                    test.Add(new XElement("DiffOriIndex", currentOriIndex - previousOriIndex));
                }
                previousOriIndex = currentOriIndex;

            }
        }
    }

}