Find item in one result in another result

mphare · October 27th, 2011, 03:30 PM

First, let me say that many people here, at work, have told me XSLT is the completely wrong language to be working in. I should be using JAVA or PERL or EXPECT, etc..

Since all my data sits squarely in the XML space, I believe there is no better language than XSLT to be doing my work.

Now, I develop using Saxon 9 on a Windows 7 box, but my code also runs in production on Solaris.

I have two temporary results, they are structured the same:

Code:

<base>
   <entity>A</entity>
   <entity>B</entity>
   <entity>C</entity>
</base>

and

<base>
   <entity>X</entity>
   <entity>Y</entity>
   <entity>Z</entity>
</base>

My quest is to determine if any of the entities in the first result exist in the second result. If it does, I would like for the function/template to give me the value-of the entity that matched. If none matched, then I'd like an empty string. I don't care if more than one matches, I just need to know if at least one matches.

I believe there to a a simple solution to this problem, one that I completely passed over as I jumped to the more difficult solutions.

Please, help!

Thanks,

- mike

mphare · October 27th, 2011, 03:58 PM

So many good things to learn about XPath.. for example.. the 'some' 'satisfies' construct.

Code:

<xsl:sequence select="some $i in base1//entity satisfies exists(base2//entity[. eq $i])"></xsl:sequence>

Seems to do exactly what I was looking for.

mhkay · October 27th, 2011, 06:04 PM

Actually it's even simpler:

Code:

base1/entity = base2/entity

returns true if any node in base1/entity has the same value as some node in base2/entity

mphare · October 28th, 2011, 10:51 AM

This is where my lack of understanding the XSLT processing model really shines.

I would have looked at base1/entity = base2/entity as meaning the two are only equal if the entire sequence: base1/entity was equal to the entire sequence: base2/entity.

As I said.. lots to learn in XPath.

Thanks again, Michael. Have a nice weekend!