But XSLT has a lot more possibilities than any templating system.
You had me up to here. Then I lost you, because you never justify it,
and this is the point we differ on.
A "templating system" like Template Toolkit has all of Perl to escape
to, without shifting gears. To extend XSLT, you have to code in some
non-XSLT language. This implies the opposite of your statement.
What axis of interest are you looking at to say what you said?
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You are quite right Merlyn, I did not make myself entirely clear. (make note to /me : never start discussing with Merlyn in the morning unless you have at least had your second cup of strong tea)The trouble I have with templates is indeed that you can (and many times have) to fall back to Perl (or whatever language is supported in the templating system), which defeats the purpose of making a clean split between logic and layout. To get the data out the database, I rely on my good, old and trusted Perl-scripts. This is the "logic" part. Once the data is in XML-format, I hand it to the XSLT-script which does all the nice formatting (putting it in tables, adding headers and footers, coding the links, calculating sums and percentages, even providing the parameters to the GD-script for making the charts). Thanks to the filtering capacities of XSLT and XPath, the same XML-data can be used to present different views or extract different type of data. I find that I rarely have to amend the basic Perl-scripts and that most of the work can be done in the XSLT-file. DTD or Schema describes the XML-data, so (theoretically) anyone who knows DTD/Schema and XSLT can work with the data my scripts provide. Practically I'm the only one who does, so I could have put everything in one big Perl-script with tons of print statements and heredocs.
CountZero "If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law
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I think you're missing the point of a templating system. It has nothing to do with making sure that your display logic doesn't have any programming stuff in it. In fact, I am switching from HTML::Template to Template Toolkit precisely because it has better programming stuff in it.
Within MVC (which it seems you do use - good for you!), you will have three programming layers, hopefully separated by rather strict APIs. Each of the layers, most likely, will have a ton of programming in them, and that's ok. Very often, one cannot convert a data structure into something to be displayed without it.
The notion that templating systems should be as dumb is possible is a mis-meme, promulgated by the facts that
- HTML::Template is the most popular templating system in Perl, even though
- it's only a stripped-down version of the first version of Template Toolkit
- it was never meant to be a complete templating system
- Most programmers think that designers make for poor programmers
- Most programmers make for poor designers
Yes, good display logic is expensive. Sometimes, the only way to do something is to drop into a full-featured language. So?
Remember something - a popular templating system for Windows programs written in Visual C++ is Visual Basic.
Being right, does not endow the right to be rude; politeness costs nothing.
Being unknowing, is not the same as being stupid.
Expressing a contrary opinion, whether to the individual or the group, is more often a sign of deeper thought than of cantankerous belligerence.
Do not mistake your goals as the only goals; your opinion as the only opinion; your confidence as correctness. Saying you know better is not the same as explaining you know better.
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My oh my, old sins do get visited upon us in eternity!dragonchild, I must confess that for the second version of my intranet claims system, I have switched to Template::Toolkit, but it still outputs XML and this XML still gets tranformed into HTML through the services of XSLT and CSS. The reason I (finally) switched to a templating system was that is allowed me to write more "condensed" code, i.e. lots of back-ground functions get "glossed over" by using the template-constructs (such as connecting to the database; managing arrays and hashes; ...). I'm still not entirely happy with the ideas behind templating systems,nor with the practical implementations, but untill I have lots of free time and start writing it myself, I will have to use and make-do with what exists! That being said Template::Toolkit is certainly one of the better templating systems around.
CountZero "If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law
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