Translator

translator.php

<?php
use \MessageFormatter;

class Translator {
	// This should be loading from a file. Eg: .po files (http://en.wikipedia.org/wiki/Gettext)
	protected static $messages = [
		'pt' => [
			'Hello world' => 'Olá mundo',
		],
		'nl' => [
			'Hello world' => 'Hello wereld',
		],
	];

	// Probably changes once during a request
	protected static $locale = 'en';

	public static function setLocale($locale) {
		static::$locale = $locale;
	}

	public static function translate($message, array $args = []) {
		// Use the localized message if found
		if (!empty(static::$messages[static::$locale][$message])) {
			$message = static::$messages[static::$locale][$message];
		}

		return MessageFormatter::formatMessage(static::$locale, $message, $args);
	}
}

function sayHello() {
	return Translator::translate('Hello world');
}

// Default = english
var_dump(sayHello());

// Portuguese
Translator::setLocale('pt');
var_dump(sayHello());

// Italian, fallback to original
Translator::setLocale('it');
var_dump(sayHello());