Templating Systems Compared and Contrasted

Independent Zope and Python consultant. Using Zope and Python since 1999.

Python 2.4 gives string templating, which is better than e.g. print statements.

Quixote - PTL:

import quixote quixote.enable_ptl()

Positives:

• allows template re-use

Negatives:

• broken html possible
• what would an html-only person think?

Zope - DTML:

• It is a generic scripting language
• Highly tied to acquisition
• Tell the html writers to leave the dtml variable alone and they can do the rest.

Positives:

• simple templates
• not just xml/html

Negatives:

• acquisition
• one big namespace
• not good with dreamweaver and friends

Zope - ZPT

Well known in the Zope community.

Positives: - Clean namespaces

• limits you from introducing business logic in templates
• source is valid xml/html

Negatives:

• 2 or 3 new languages
• macros are confusing, especially nesting them
• very tied to Zope
• tied to generating xml/html

Cheetah

• not limited to xml
• not tied to one framework

Positives:

• familiar, python-like
• compact
• caching

Negatives:

• not enough python-like, so yet another language
• we're not helping the web monkeys

Nevow: really aimed at twisted.nevow

Positives:

• Clean separation of data, logic and presentation
• does help the web monkeys

Negatives:

• very verbose
• meant for Twisted and yes it is twisted!

Others: - Myghty

• Preppy
• XSLT
• PyMeld, meld2, meld3
• Kid attribute language like ZPT

Types: preprocessor, class based, attribute languages, DOM based

We want to:

• Replace attributes, values and tags.
• Repeat tags
• Remove attributes, values, tags and node
• html quoting

What if we did that?

• simple
• no new languages
• work with raw html

Twiddler

• n = t.getById(Something)
• n.replace(value, tag, **attributes)
• n.repeat(value, tag, **attributes)
• n.remove()
• Put code in html comments, mostly at the top.
• t.clone() for reusing common material
• Use name attributes:

Positives:

• works with real html
• no new language
• simple as possible

Negatives:

• verbose
• not battle-proven
• maybe slow

I hadn't seen meld3 when i started developing Twiddler, but they are scarily similar. It uses meld:id attribute.

But it's not just about html. Think about sending an email. Or a css file. Or things that are just not xml.

What about i18n, html quoting, stx, rst? We can do that.

See the presentation.