compare 2 xml files

nguna · March 27th, 2009, 08:10 AM

Hi,

I'm trying to compare 2 xml files and if they are different want to output the nodenames and values where they differ.
I managed to compare then using the deep-equal() function but i don't know how to output the differences. Please help

mhkay · March 27th, 2009, 08:28 AM

Saxon has a variant of the deep-equal() function that outputs such information (though not necessarily in the format you want). See

http://www.saxonica.com/documentatio...deepequal.html

nguna · March 27th, 2009, 12:24 PM

Thanks Micheal,
I don't quite understand the function ( what does collation means here )
Could you please give an example

Martin Honnen · March 29th, 2009, 08:34 AM

The collation is specified in terms of a URI where the XSLT processor you use defines how to URI looks exactly. For Saxon 9 you can find an explanation here: http://www.saxonica.com/documentatio...collation.html
However you can simply use (), the empty sequence for that argument and the default collation is used which I think is the Unicode codepoint collation.
To give you an example using saxon:deep-equals, assume the XML input is as follows:

Code:

<root>
  <foo>bar</foo>
  <foo>BAR</foo>
</root>

and we want to compare root/foo[1] and root/foo[2] according to the English language as used in the US, one time case-sensitive, one time case-insensitive, then we can use

Code:

<xsl:stylesheet
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  version="2.0"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:saxon="http://saxon.sf.net/"
  exclude-result-prefixes="xs saxon">
  
  <xsl:output method="text"/>
  
  <xsl:template match="/">
    <xsl:value-of select="
      saxon:deep-equal(root/foo[1], root/foo[2], 'http://saxon.sf.net/collation?lang=en-US', '?'),
      saxon:deep-equal(root/foo[1], root/foo[2], 'http://saxon.sf.net/collation?lang=en-US;ignore-case=yes', '?')"
      separator="
"/>
  </xsl:template>

</xsl:stylesheet>

The output (tested with Saxon 9.1.0.5 Java) is as follows:

Warning: deep-equal(): text() values differ ("/root/foo[1]/text()[1], /root/foo[2]/text()[1]: bar", "BAR")
Warning: deep-equal(): nodes at position 1 differ
false
true

nguna · March 30th, 2009, 06:17 AM

Thanks for the information Martin

I want to do the comparison in datapower and it doesn not suppory saxon extensions. Are there any other ways to do is without using extensions ?

mhkay · March 30th, 2009, 07:02 AM

Datapower doesn't even support XSLT 2.0 deep-equal()!

You've got various options:

* write it yourself

* get a product like DeltaXML (but Saxon is cheaper)

nguna · March 30th, 2009, 07:26 AM

My only option is to write my own code
Could you please give me some idea on where to start..
thanks

mhkay · March 30th, 2009, 06:38 PM

>My only option is to write my own code
>Could you please give me some idea on where to start..

Try writing a recursive template diag-deep-equal() as follows:

compare two nodes using deep-equal().

if equal, exit with result true.

if not equal, examine the children. If the number of children of the two nodes is different, output an xsl:message to say so and return false. Otherwise compare the child nodes one-by-one, using a recursive call on your function diag-deep-equal(). When you hit the first pair that are not equal (the function returns false), output an xsl:message to say which elements you found, and return false.

Use a supporting function to output the path to a node to construct diagnostics, which you can obtain by walking up the ancestor axis.

[I know that this is well beyond the level of anything you've written before. Please don't come back asking me to implement it for you. You asked for advice on where to start, and I've given you that. Now it's your job to finish.]

nguna · March 31st, 2009, 04:04 AM

Thanks for the suggestion