Passing normal Java Objects to Transformer.setParameters

BuckBazooka · December 1st, 2010, 04:05 AM

Hi,
Can one pass plain java objects to setParameters and use them in a stylesheet without having them transformed into a string?

I don't know how to define the parameter in the stylesheet in order to be able to access as a normal java object. Is it possible?

The only examples I saw were always using Strings, Double, Integers or values. Can we also pass a java object like com.myown.GreatJavaObject?

Thanks

mhkay · December 1st, 2010, 05:23 AM

The JAXP interface doesn't define what kinds of Java object you can pass to setParameter(), or how such objects are mapped to XPath values. It depends which implementation of JAXP you are using.

If you are using Saxon, the rules can be found at http://www.saxonica.com/documentatio...ion-result.xml (the rules are expressed in terms of converting the result of an extension function, but the same rules apply for setParameter()). Note the last rule ("If none of the above, it's passed as a wrapped Java object") - in such cases, the only thing your stylesheet can usefully do with the value is to pass it to a Java extension function.

If you are using Xalan, the rules will be different.

BuckBazooka · December 1st, 2010, 06:34 AM

Thanks for your reply.
As I said I am using saxon-EE, and today I am using in my stylesheet something similar to this:

Code:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0" 
	xmlns:abc="java:com.abc.MyClass"
>
	
	<xsl:output method="xml" indent="yes" encoding='UTF-8' />
	<xsl:variable name="myObject" select="abc:new()" />

...

	<xsl:template match="i18n_translate">
		<xsl:value-of select="abc:myMethod($myObject, 'aparameter')" />
	</xsl:template>

</xsl:stylesheet>

So my question is really, is it possible to instantiate the object myObject in my Java program and pass it as a parameter to my stylesheet with the transformer's method setParameters, instead of instantiating in my stylesheet where my object is used as a variable? In code I would like my solution to look like this:

My Java program

Code:

MyClass myObject = new MyClass();
transformer.setParameters("myObject", myObject);

In my Stylesheet it would be something like this:

Code:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0" 
	xmlns:abc="java:com.abc.MyClass"
>
	
	<xsl:output method="xml" indent="yes" encoding='UTF-8' />
	<xsl:param name="myObject" />

...

	<xsl:template match="i18n_translate">
		<xsl:value-of select="abc:myMethod($myObject, 'aparameter')" />
	</xsl:template>

</xsl:stylesheet>

Could something similar to this make sence?

samjudson · December 1st, 2010, 06:57 AM

a) If you look at your original post you didn't say you were using Saxon at all.

b) Have you tried the code you posted? Seems the quickest and easiest way to work out if you can do it is to try and see if it works. I would suspect from what Michael said that it will work exactly as you expect.

BuckBazooka · December 2nd, 2010, 06:18 AM

Thanks again for your answer.
Sorry if I forgot to mention Saxon.

Thanks for giving me inspiration to continue my quest. You are right my code is working. I had forgotten actually to place, in the property list, the object I wanted to pass!!!

Very embarrassing, I was making loads of tests and I have forgotten the most important. I had gotten confused when I saw the error message:

Code:

net.sf.saxon.trans.XPathException: Cannot convert from xs:string to myObject

and really got confused. That is when I thought it was not accepting objects. Stupid thought....

Anyhow passing objects to stylesheet through properties and referring the object in the stylesheet works like a charm, and with this in hand I can solve all problems.

I will solve one of the problems I had posted (Fetching variable from an XSLT transformation) with this technique.

One last thing. Saxon is REALLY GREAT. I like it a lot, fast and as you guys told me before much better than the old XSLT V 1.0 I use to work with. So thanks a lot.