Compare two XML files

[dawgfather]

Hi there!

Does anyone know how to compare two xml files?

what i wanna do is compare the two xml Files and then display the difference to the datagrid...thanks in advance.

[nemaroller]

You could probably get away with writing XSL that would be the envy of your peers:

<?xml version='1.0'?>
 
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
   <xsl:output method="xml"/>
 
<xsl:variable name="doc-file">[url]http://mymachine.com/changed.xml[/url]</xsl:variable>
 
<!-- copy everything that has no other pattern defined -->
<xsl:template match="* | @*">
   <xsl:copy><xsl:copy-of select="@*"/><xsl:apply-templates/></xsl:copy>
</xsl:template>
 
<!-- check for every <address> element if an updated one exists -->
<xsl:template match="//address">
   <xsl:param name="addresseeName">
      <xsl:value-of select="addressee"/>
   </xsl:param>
 
   <xsl:choose>
      <xsl:when test="document($doc-file)//addressee[text()=$addresseeName]">
         <xsl:copy-of select="document($doc-file)//address[child::addressee[text()=$addresseeName]]"/>
      </xsl:when>
      <xsl:otherwise>
         <xsl:apply-templates/>
      </xsl:otherwise>
   </xsl:choose>
</xsl:template>

But that's mind-numbing stuff and I certainly wouldn't be able to help you.

[nemaroller]

You can use .Net xml classes to find the differences, but differences really depend on the structure of the XML documents in queston.

I mean I could have

<root>
<Address>
<AddressID>1</AddressID>
<StreetNumber>111</StreetNumber>
</Address>
<Address>
...

and

<root>
<Address>
<AddressID>1</AddressID>
<StreetNumber>123</StreetNumber>
</Address>
<Address>
...

And you could certainly tell that for the Address uniquely identified by 1, there is a difference in the two XML documents (the streetnumber is differen).

Or, it could be that the 2nd XML document has a different address structure :

<root>
<Address>
<AddressID>1</AddressID>
<StreetNumber>111</StreetNumber>
<StreetName>Franklin</StreetName>
</Address>
<Address>
...

in which case the difference would be this 2nd file has a StreetName child attribute.

So, which is the one you want?

[dawgfather]

i guess the first example of the xml document is what i am looking for. what i'm doing is scanning a computer for software. and then after a few days later scan the machine again. and then compare the two scans. i'm writing the files as xml schemas....thanks

[Mr.No]

I suppose you want .NET code to compare XML files but in the meantime have a look at this tool XML Diff Demo