i18n for XSLT in 4Suite

Prodded by discussion on the CherryPy list I have implemented and checked in a 4Suite XSLT extension for internationalization using Python's gettext facilities for the underlying support. Here is how it works. Sample XML:

<doc>
  <msg>hello</msg>
  <msg>goodbye</msg>
</doc>

Sample XSLT:

<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:f="http://xmlns.4suite.org/ext"
  extension-element-prefixes="f"
>
  <f:setup-translations domain="test"/>
  <xsl:template match="msg">
    <f:gettext><xsl:apply-templates/></f:gettext>
  </xsl:template>
</xsl:stylesheet>

The f:setup-translations and f:gettext extension elements are the key. The former looks up and installs the domain "test" for use in your XSLT. Replace it with the domain used by your application. The latter extension evaluates its body to get a string value, and then looks up this string in the installed translation.

Assuming you have a test.mo installed in the right place, say that translates "hello" to "howdy" and "goodbye" to "so long".

$ 4xslt test.xml test.xsl
<?xml version="1.0" encoding="UTF-8"?>
howdy
  so long

I trimmed some white space for formatting, but you get the idea. The translations are applied automatically according to your locale.

This operates via Python's gettext facilities which means that it's much more efficient than, say, the docbook XSLT approach to i18n.

For those who want to give it a whirl, here's a quick step-by-step. All the needed files are available here on copia.

Create a sandbox locale directory:

mkdir -p /tmp/locale/en_US/LC_MESSAGES/

Copy in the catalog. You may need to create a different catalog for your own language if your system will not be selecting en_US as locale (remember that you can hack the locale via the environment)

cp en_US.mo /tmp/locale/en_US/LC_MESSAGES/test.mo

Your locale is probably not en_US. If not, you can:

  • temporarily override your locale to en_us using export LANG=en_US, or the equivalent command for your shell
  • create translations for your locale (just two strings to translate). I use poedit, which is makes dealing with .pos simple enough. Then replace en_US in all the above instructions with your own locale and the .mo file you created.

Anyway, the f:setup-translations and f:gettext extensions are now checked into 4Suite. You can either update to current 4Suite CVS, or just download the one changed file, Ft/Xml/Xslt/BuiltInExtElements.py and copy it into your 4Suite codebase. It works fine as a drop-in to 4Suite 1.0b1.

[Uche Ogbuji]

via Copia