Tom Moertel's Weblog: PXSL Tools 1.0: Your ticket out of XML Hell

PXSL Tools 1.0: Your ticket out of XML Hell

Tom Moertel — Mon, 17 Dec 2007 22:33:00 -0500

XML is fine for representing document-like things, but when it’s twisted to represent build recipes, configuration files, and little programming languages, it opens the gates to XML Hell. Once the gates are opened, the demons of cargo-cult thinking are loosed upon the world, where they are free to trick innocent programmers into working with grotesquely twisted XML documents – something no human mind was designed to comprehend. Ensnared, these programmers are slowly drawn into the depths of XML Hell, from which their lamentations echo across the universe.

When the demons of cargo-cult thinking come for you, don’t be ensnared! Instead, be prepared – with PXSL – the Parsimonious XML Shorthand Language (pronounced “pixel”).

What’s PXSL? It’s a luxurious, thermonuclear smoking jacket that you can slip on using a convenient preprocessor. Use it whenever you see grotesque XML on the horizon. Within PXSL’s plush (and stylish) protection, you can create all the nasty, twisted XML that may be demanded of you, but you need not descend into XML Hell to do it. Instead, you can work from the comfort of a well-stocked lounge, where clarity and conciseness are always on tap.

For example, here’s a snippet from an XSLT stylesheet, in the original XML:

<xsl:template match="/">
  <xsl:for-each select="//*/@src|//*/@href">
    <xsl:value-of select="."/>
    <xsl:text>&#10;</xsl:text>
  </xsl:for-each>
</xsl:template>

And here’s the same snippet, written in PXSL:

template /
  for-each //*/@src|//*/@href
    value-of .
    text <<&#10;>>

Isn’t that refreshing?

Why PXSL?

There are lots of XML shorthands available. (The PXSL FAQ lists about ten of them.) So why choose PXSL? Here’s why:

PXSL lets you intermix PXSL and XML syntax in one document. Feel free to use whichever syntax works best for each portion of your documents. (See the PXSL documentation for some examples.)
PXSL is customizable with application-specific shortcuts. (The PXSL snippet above, for example, uses XSLT shortcuts. Again, the PXSL documentation has examples.)
PXSL has a powerful macro system that lets you build complicated document structures safely and conveniently. (Read about macros in the PXSL documentation. For an advanced example of what you can do with PXSL macros, see this article on refactoring XSLT one-offs into clean, maintainable code.)

Also, PXSL is battle tested. It was first released in 2003 and has been saving people from XML Hell since. People who try it seem to like it:

I think PXSL could do wonders for soothing my irrational hatred for all things XML. —kowey
Impressive… I converted some of my files from XML to PXSL and the readability was much improved. —chris
Quite aside from the fact that XSLT is finally somewhat readable, the fact that you’ve added a serious macro system means that some serious scripting of XML can occur. I’m very impressed. —invisible

The next time you’re headed for XML Hell, why not give the venerable PXSL a try? You might just find that you like it, too.

This public service announcement was brought to you in celebration of the 1.0 release of the pxsl-tools package. The PXSL-to-XML compiler pxslcc is written in Haskell and uses the cross-platform Haskell Cabal build/package system to let you use PXSL just about anywhere.

"PXSL Tools 1.0: Your ticket out of XML Hell" by Tom Moertel

Mon, 30 Jun 2008 10:21:04 -0400

hdh, there is not a PXSL mode for Emacs, as far as I know.

Writing one would be an interesting exercise. A simple PXSL mode, supporting only PXSL syntax, would be straightforward to implement. A more advanced PXSL mode, offering XML editing features within PXSL’s XML fragments (you can embedd XML in PXSL documents), would be a much more difficult project.

If you (or anybody) is interested in writing a PXSL mode, I would be happy to add it to the official PXSL distribution. ;-)

Cheers,
Tom

"PXSL Tools 1.0: Your ticket out of XML Hell" by hdh

Mon, 30 Jun 2008 04:07:23 -0400

Hi, is there an emacs mode for PXSL? I see the PXSL page has “mode: outline” at the end, but I don’t see any use for it when editing PXSL.

"PXSL Tools 1.0: Your ticket out of XML Hell" by Tom Moertel

Sun, 20 Apr 2008 10:45:47 -0400

Thanks for the kind words, Quark! You made my day. :-)

"PXSL Tools 1.0: Your ticket out of XML Hell" by Quark

Fri, 18 Apr 2008 18:30:54 -0400

1.0! Lovely :). I’ve been a PXSL user for years now. PXSL is a really nice language and a really elegant design.

I use it for all web pages I generate from XML, and these days I use it for a fair number of configuration files too (e.g. for OPML for bookmarks).

Thanks for the lovely tool Tom.

"PXSL Tools 1.0: Your ticket out of XML Hell" by defel

Mon, 04 Feb 2008 04:48:04 -0500

Many thanks for PXSL .. I am using XML and XSL for years, and waited always for something like pxsl, great utility! :)

"PXSL Tools 1.0: Your ticket out of XML Hell" by Cory von Wallenstein

Mon, 07 Jan 2008 09:01:08 -0500

Thanks to your tip that I picked up last week, I’ve found myself requiring my XML validator probably about a quarter as often as I required when I was buried deep in XML Hell. Thanks!

"PXSL Tools 1.0: Your ticket out of XML Hell" by Tom Moertel

Sun, 23 Dec 2007 21:09:51 -0500

Kristian, the PXSL-to-XML preprocessor is written in Haskell, but the result is a stand-alone binary – you don’t need to learn (or use) Haskell to use it. If you’re running Fedora Linux, for example, you can just install one of the pxsl-tools RPMs I’ve packaged, and you’ll be ready to roll. Other folks have contributed binaries for Windows and Mac OS X, but they are a bit out of date. (Contributions of more-recent versions are welcome.)

"PXSL Tools 1.0: Your ticket out of XML Hell" by Kristian

Sun, 23 Dec 2007 18:56:55 -0500

That’s very nice and all (and I remember you espousing PSXL before on HuSi), but what if one isn’t running Haskell? Any idea how har it would be to wrap this for, say, Python?