Basics for setting up localized PHP applications using gettext functions.

PHP_I18N_basics.md

Overview

Localizing/internationalizing any PHP application is easy through gettext functions. Basically you'll have a set of localization files (*.po) that have a binary format version (*.mo) across a simple and standard directory structure. Then gettext functions will use existing binary files based on current language locale.

Directory structure and localization files

locale/
├── en_US
│   └── LC_MESSAGES
│       ├── messages.mo
│       └── messages.po
└── pt_PT
    └── LC_MESSAGES
        ├── messages.mo
        └── messages.po

*.mo files are to be auto generated based on pot (*.po) files.

pot file example

In this case the file was generated using Poedit but you can create using your favorite editor.

msgid ""
msgstr ""
"Project-Id-Version: YouProjectID\n"
"POT-Creation-Date: 2013-07-30 12:44-0000\n"
"PO-Revision-Date: 2013-07-30 12:56-0000\n"
"Last-Translator: James Brown <jb@uuuuuuuuuuu.com>\n"
"Language-Team: jb@Music <jb@uuuuuuuuuuu.com>\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"X-Generator: Poedit 1.5.7\n"
"X-Poedit-KeywordsList: _;gettext;gettext_noop\n"
"X-Poedit-Basepath: .\n"
"X-Poedit-SourceCharset: UTF-8\n"
"Language: English\n"

msgid "TotalOnPayment"
msgstr "Total on payment"

This example contains one localized string identified by TotalOnPayment.

Create a bash script for generating locales binary (*.mo) files

gettext functions will read binary files that must be generated. This is a requirement and can be easily satisfied with the help of simple bash script:

#!/bin/sh

# repeat for all needed *.po files
find . -name \*.po -execdir msgfmt messages.po -o messages.mo \;

Make script file executable:

$ chmod +x generate-locales-binaries.sh

For example if saved as generate-locales-binaries.sh every time you edit .po files just execute to have all binaries updated:

$ ./generate-locales-binaries.sh

Set locale on your PHP code

<?php

// I18N support
$language = 'pt_PT';
putenv("LANG=$language"); 
setlocale(LC_ALL, $language);

// set the text domain as 'messages' and 
//  define where *gettext* is going to find your resources
$domain = 'messages';
bindtextdomain($domain, "locale"); 
textdomain($domain);

Usage example

<?php

/* ... */

echo(gettext('TotalOnPayment'));

/* ... */

The output would be...

Total on payment