I have made an xslt stylesheet wich works great.

In this stylesheet there are includes to other stylesheets.
What i want is to 'extend' xslt to be able to give the user choises for different 'themes' in a website.
The stylesheet i made now is really basic, it has no css, no javascript, etc.

I was wondering what the best way is to extend this stylesheet to add for example some css or javascript without having to copy the entire xslt directory to another directory and make the changes there. When i do that i have to edit my basic theme, then copy my changes to my other 'theme' wich is kinda stupid i think.

My problem is i can let my php check if a file exists (for example my Advanced file) and if it doesn't exist, fall back on the Basic file, but then all the includes in my xslt files should also do this and i don't know if this is possible and if it is a smart choice.

If anyone has some idea or has already done this please explain to me how to do it, my xslt sheet isn't too big so i can make drastic changes if needed.

I hope i explained my problem good enough for you guys to understand :)

Use xsl:import. You can define a number of specializations of your stylesheet, each of which overrides some or all of its templates and other declarations. Each should import the common generic code that you have already written. You then start the processing by invoking the "special-purpose" stylesheet, which in turn invokes the general-purpose stylesheet.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

Thank you very much for the info michael, i think i understand the concept, looking forward to try it out, will do so this weekend!

Wow, this works like a charm. I can extend my themes fully now. I can develop in the 'Basic' theme and then add some styles in my 'Styled' theme. Thanks for the info michael, i finnaly get this import tag, it's awsome!