[xsl] Simple XML Diff

Subject: [xsl] Simple XML Diff
From: Mark Anderson <mark.anderson@xxxxxxxxxxxxxxxxxxx>
Date: Thu, 10 Jul 2008 21:17:03 +0100
Hi All

I'm trying to write an XML template that will compare two XML files that have
*identical* structures. I thought it would be easy or in the archives, but all
I can find is references to full DIFF functions that look for new elements,
etc.

My style sheet and an XML file (let's call it "new.xml") will get called from
a 32-bit windows app and it needs to transform the XML to HTML.

My stylesheet will contain a reference to a "master" xml doc (let's call it
"master.xml").

What I need to do is compare every element an attribute in new.xml with the
equivalent in master.xml and then highlight differences (the easy bit). What
I'm stuck with is something that (I'm guessing) is dead easy, but I can't
figure it out: how to iterate through all elements and attributes in new.xml
and find the equivalent in master.xml.

Example

"New.xml"
<nodeA attribute1="XXX" attribute2="YYY">
        <nodeA1>ZZZ</nodeA1>
</nodeA>
<nodeB>AAA</nodeB>
<nodeC>BBB</nodeC>

"Master.xml"
<nodeA attribute1="111" attribute2="222">
        <nodeA1>FFF</nodeA1>
</nodeA>
<nodeB>AAA</nodeB>
<nodeC>BBB</nodeC>

So, this XSLTemplate I need to create needs to compare

New.xml/nodeA/@attribute1 to Master.xml/nodeA/@attribute1
New.xml/nodeA/nodeA1 to Master.xml/nodeA/nodeA1

I'm guessing there's a single apply-templates element I can use that will do
this. The contents of this will be writing either HMTL listing all the
elements that do no match in the two files. I don't anticipate a problem with
this.

So the output would say something like:
New.xml/nodeA/@attribute1 = XXX   -   Master.xml/nodeA/@attribute1 = 111
New.xml/nodeA/nodeA1 = ZZZ        -   Master.xml/nodeA/nodeA1 = FFF

Ideally, I'd like to ignore certain elements (like creation date and time
fields) as they will always be different between New.xml and Master.xml

I have to use XSLT1.0 for this

Could someone point me in the right direction?

Thanks

Mark

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