Petal::I18N.3pm

Langue: en

Version: 2004-09-03 (debian - 07/07/09)

Section: 3 (Bibliothèques de fonctions)

Sommaire

NAME

Petal::I18N - Attempt at implementing ZPT I18N for Petal

SYNOPSIS

in your Perl code: 
   use Petal;
   use Petal::TranslationService::Gettext;
 
   my $translation_service = new Petal::TranslationService::Gettext (
       locale_dir  => '/path/to/my/app/locale',
       target_lang => gimme_target_lang(), 
   );
 
   my $template = new Petal (
       file => 'example.html',
       translation_service => $translation_service
   );
 
   # we want to internationalize to the h4x0rz 31337 l4nGu4g3z. w00t!
   my $translation_service = Petal::TranslationService::h4x0r->new();
   my $template = new Petal (
       file => 'silly_example.xhtml',
       translation_service => $ts,
   );
 
   print $template->process ();

I18N Howto


Preparing your templates:

Say your un-internationalized template looks like this:

   <html xmlns:tal="http://purl.org/petal/1.0/">
     <body>
       <img src="/images/my_logo.png"
            alt="the logo of our organisation" />
 
       <p>Hello,
          <span petal:content="user_name">Joe</span>.</p>
 
       <p>How are you today?</p>
     </body>
   </html>

You need to markup your template according to the ZPT I18N specification, which can be found at http://dev.zope.org/Wikis/DevSite/Projects/ComponentArchitecture/ZPTInternationalizationSupport

   <html xmlns:tal="http://purl.org/petal/1.0/"
         xmlns:i18n="http://xml.zope.org/namespaces/i18n"
         i18n:domain="my_app">
     <body>
       <img src="/images/my_logo.png"
            alt="the logo of our organisation"
            i18n:attributes="alt" />
       <p i18n:translate="">Hello, <span petal:content="user_name">Joe</span>.</p>
       <p i18n:translate="">How are you today?</p>
     </body>
   </html>

Extracting I18N strings:

Once your templates are marked up properly, you will need to use a tool to extract the I18N strings into .pot (po template) files. To my knowledge you can use i18ndude (standalone python executable), i18nextract.py (part of Zope 3), or I18NFool.

I use i18ndude to find strings which are not marked up properly with i18n:translate attributes and I18NFool for extracting strings and managing .po files.

Assuming you're using i18nfool:

   mkdir -p /path/to/my/app/locale
   cd /path/to/my/app/locale
   i18nfool-extract /path/to/my/template/example.html
   mkdir en
   mkdir fr
   mkdir es
   i18nfool-update

Then you translate the .po files into their respective target languages. When that's done, you type:

   cd /path/to/my/app/locale
   i18nfool-build

And it builds all the .mo files.

Making your application use a Gettext translation service:

Previously you might have had:

   use Petal;
   # lotsa code here
   my $template = Petal->new ('example.html');

This needs to become:

   use Petal;
   use Petal::TranslationService::Gettext;
   # lotsa code here
   my $template = Petal->new ('example.html');
   $template->{translation_service} = Petal::TranslationService::Gettext->new (
       locale_dir  => '/path/to/my/app/locale',
       target_lang => gimme_language_code(),
   );

Where gimme_language_code() returns a language code depending on LC_LANG, content-negotiation, config-file, or whatever mechanism you are using to decide which language is desired.

And then?

And then that's it! Your application should be easily internationalizable. There are a few traps / gotchas thought, which are described below.

BUGS, TRAPS, GOTCHAS and other niceties


Translation Phase

The translation step takes place ONLY ONCE THE TEMPLATE HAS BEEN PROCESSED.

So if you have:

   <p i18n:translate="">Hello,
     <span i18n:name="user_login" tal:replace="self/user_login">Joe</span>
   </p>

It most likely will not work because the tal:replace would remove the <span> tag and also the i18n:name in the process.

This means that instead of receiving something such as:

   Hello, ${user_login}

The translation service would receive:

   Hello, Fred Flintstone

Or

   Hello, Joe SixPack

etc.

To fix this issue, use tal:content instead of tal:replace and leave the span and its i18n:name attribute.

Character sets

I haven't worried too much about them (yet) so if you run into trouble join the Petal mailing list and we'll try to fix any issues together.

Limitations

At the moment, Petal::I18N supports the following constructs:

xmlns:i18n="http://xml.zope.org/namespaces/i18n"
i18n:translate
i18n:domain
i18n:name
i18n:attribute

It does *NOT* (well, not yet) support i18n:source, i18n:target or i18n:data.