Re: [xsl] Unravelling Imports

["G. Ken Holman" <gkholman@xxxxxxxxxxxxxxxxxxxx>]

At 2012-04-11 20:36 +0100, ihe onwuka wrote:
> There is a supposed requirement that we deliver monolithic XSLT with
> includes unravelled (there are no imports).
>
> I don't need to be convinced it's a bad and misguided idea but I won't
> close off anyone who wants to comment as they may think of stuff that I
> haven't.
>
> The purpose of my post though is this.
>
> Suppose we did go ahead and code with imports, would it be possible to
> define a transform that mechanically transformed everything into monolithic
> XML.
>
> I'm thinking it would involve alot of use of priorities at the very least.

For "includes" it isn't a problem ... simply stream the included 
fragments in-situ.  I cannot think of any changes to the coding.

But for "imports" I think it would be a challenge to do quickly or 
even at all completely.  Any <xsl:apply-imports> that you have could 
not easily be changed into <xsl:next-match> because you cannot keep 
the other matches in the original fragment from being engaged.  And 
that is only if you are working with XSLT 2.0.

Then there is the mixing of user-specified priorities with your own 
imposed priorities that mimic importation precedence.  If a user used 
arbitrarily large priority values, how would you ensure your imposed 
values would always exceed those?

You would have to aggregate like-named attribute sets in such a way 
as to eliminate lower-priority like-named attributes.

You would have to cull like-named template rules of lower priority 
than the highest of each.

Because precedence trumps priority it might be a good first step just 
to assign higher priorities of the same value to templates higher in 
import precedence ... adding in any user-specified priorities to the 
number selected for that fragment.

It would likely work for the simplest uses of XSLT.  But if you are 
using <xsl:import> then it must be for a good reason of overriding 
constructs, which then makes it a challenge.

I think it would take a lot more thinking than provided for in a 
volunteer mail list response.

But I hope the above helps somewhat.

. . . . . . . . . Ken

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