Locale::Maketext::Gettext::Functions3pm

Usage

  use Locale::Maketext::Gettext::Functions;
  bindtextdomain(DOMAIN, LOCALEDIR);
  textdomain(DOMAIN);
  get_handle("de");
  print __("Hello, world!\n");

Overview

Locale::Maketext::Gettext::Functions is a functional interface to Locale::Maketext::Gettext(3) (and Locale::Maketext(3)). It works exactly the GNU gettext way. It plays magic to Locale::Maketext(3) for you. No more localization class/subclasses and language handles are required at all.

The "maketext", "dmaketext", "pmaketext" and "dpmaketext" functions attempt to translate a text message into the native language of the user, by looking up the translation in an MO lexicon file.

Functions

bindtextdomain(DOMAIN, LOCALEDIR)

Register a text domain with a locale directory. Returns "LOCALEDIR" itself. If "LOCALEDIR" is omitted, the registered locale directory of "DOMAIN" is returned. This method always success.

textdomain(DOMAIN)

Set the current text domain. Returns the "DOMAIN" itself. if "DOMAIN" is omitted, the current text domain is returned. This method always success.

get_handle(@languages)

Set the language of the user. It searches for an available language in the provided @languages list. If @languages was not provided, it looks checks environment variable LANG, and HTTP_ACCEPT_LANGUAGE when running as CGI. Refer to Locale::Maketext(3) for the magic of the "get_handle".

$message = maketext($key, @param...)

Attempts to translate a text message into the native language of the user, by looking up the translation in an MO lexicon file. Refer to Locale::Maketext(3) for the "maketext" plural grammar.

$message = __($key, @param...)

A synonym to "maketext()". This is a shortcut to "maketext()" so that it is cleaner when you employ maketext to your existing project.

($key, @param...) = N_($key, @param...)

Returns the original text untouched. This is to enable the text be caught with xgettext.

$message = dmaketext($domain, $key, @param...)

Temporarily switch to another text domain and attempts to translate a text message into the native language of the user in that text domain. Use "--keyword=dmaketext:2" for the xgettext utility.

$message = pmaketext($context, $key, @param...)

Attempts to translate a text message in a particular context into the native language of the user. Use "--keyword=pmaketext:1c,2" for the xgettext utility.

$message = dpmaketext($domain, $context, $key, @param...)

Temporarily switch to another text domain and attempts to translate a text message in a particular context into the native language of the user in that text domain. Use "--keyword=dpmaketext:2c,3" for the xgettext utility.

encoding(ENCODING)

Set or retrieve the output encoding. The default is the same encoding as the gettext MO file. You can specify "undef", to return the result in unencoded UTF-8.

key_encoding(ENCODING)

Specify the encoding used in your original text. The "maketext" method itself is not multibyte-safe to the _AUTO lexicon. If you are using your native non-English language as your original text and you are having troubles like:

Unterminated bracket group, in:

Then, specify the "key_encoding" to the encoding of your original text. Returns the current setting.

WARNING: You should always use US-ASCII text keys. Using non-US-ASCII keys is always discouraged and is not guaranteed to be working.

encode_failure(CHECK)

Set the action when encode fails. This happens when the output text is out of the scope of your output encoding. For example, output Chinese into US-ASCII. Refer to Encode(3) for the possible values of this "CHECK". The default is "FB_DEFAULT", which is a safe choice that never fails. But part of your text may be lost, since that is what "FB_DEFAULT" does. Returns the current setting.

die_for_lookup_failures(SHOULD_I_DIE)

Maketext dies for lookup failures, but GNU gettext never fails. By default Lexicon::Maketext::Gettext follows the GNU gettext behavior. But if you are Maketext-styled, or if you need a better control over the failures (like me :p), set this to 1. Returns the current setting.

reload_text()

Purges the MO text cache. By default MO files are cached after they are read and parsed from the disk, to reduce I/O and parsing overhead on busy sites. reload_text() purges this cache, so that updated MO files can take effect at run-time. This is used when your MO file is updated, but you cannot shutdown and restart the application. for example, when you are a virtual host on a mod_perl-enabled Apache, or when your mod_perl-enabled Apache is too vital to be restarted for every update of your MO file, or if you are running a vital daemon, such as an X display server.

%Lexicon = read_mo($MO_file)

Read and parse the MO file. Returns the read %Lexicon. The returned lexicon is in its original encoding.

If you need the meta information of your MO file, parse the entry $Lexicon{""}. For example:

  /^Content-Type: text\/plain; charset=(.*)$/im;
  $encoding = $1;

Notes

NOTE: Since localization classes are generated at run-time, it is not possible to override the Maketext language functions, like "quant" or "numerate". If that is your concern, use Locale::Maketext::Gettext(3) instead. Suggestions are welcome.

You can now add/remove languages/MO files at run-time. This is a major improvement over the original Locale::Maketext::Gettext(3) (and Locale::Maketext(3)). This is done by registering localization classes with random IDs, so that the same text domain can be re-declared infinitely, whenever needed (language list changes, LOCALEDIR changes, etc.) This is not possible to the object-interface of Locale::Maketext::Gettext(3) (and Locale::Maketext(3)).

Language addition/removal takes effect only after "bindtextdomain" or "textdomain" is called. It has no effect on "maketext" calls. This keeps a basic sanity in the lifetime of a running script.

If you set "textdomain" to a domain that is not "bindtextdomain" to specific a locale directory yet, it will try search system locale directories. The current system locale directory search order is: /usr/share/locale, /usr/lib/locale, /usr/local/share/locale, /usr/local/lib/locale. Suggestions are welcome.

Story

The idea is that: I finally realized that, no matter how hard I try, I can never get a never-failure "maketext". A common wrapper like:

  sub __ { return $LH->maketext(@_) };

always fails if $LH is not initialized yet. For this reason, "maketext" can hardly be employed in error handlers to output graceful error messages in the natural language of the user. So, I have to write something like this:

  sub __ {
      $LH = MyPkg::L10N->get_handle if !defined $LH;
      return $LH->maketext(@_);
  }

But what if "get_handle" itself fails? So, this becomes:

  sub __ {
      $LH = MyPkg::L10N->get_handle if !defined $LH;
      $LH = _AUTO->get_handle if !defined $LH;
      return $LH->maketext(@_);
  }
  package _AUTO;
  use base qw(Locale::Maketext);
  package _AUTO::i_default;
  use base qw(Locale::Maketext);
  %Lexicon = ( "_AUTO" => 1 );

Ya, this works. But, if I always have to do this in my every application, why should I not make a solution to the localization framework itself? This is a common problem to every localization projects. It should be solved at the localization framework level, but not at the application level.

Another reason is that: Programmers should be able to use "maketext" without the knowledge of object-oriented programming. A localization framework should be neat and simple. It should lower down its barrier, be friendly to the beginners, in order to encourage the use of localization and globalization. Apparently the current practice of Locale::Maketext(3) does not satisfy this request.

The third reason is: Since Locale::Maketext::Gettext(3) imports the lexicon from foreign sources, the class source file is left empty. It exists only to help the "get_handle" method looking for a proper language handle. Then, why not make it disappear, and be generated whenever needed? Why bother the programmers to put an empty class source file there?

How neat can we be?

imacat, 2003-04-29