Installation

Different installation methods:

• NPM: npm install lang.js
• Bower: bower install lang.js
• Manually: Download latest release

Documentation

Initialization

var lang = new Lang({
    messages: source,
    locale: 'fr',
    fallback: 'zn'
});

To use Lang.js we need to specify at least the messages sources. This can be done during instantiation as shown in the previous code or later using the setMessages() method.

Messages source format

The messages source format looks like:

{
    "locale1.name": {
        "key1": "value1",
        "key2": "value2",
        // ... and more key-value pairs.
    },
    "locale2.name": {
        "key1": "value1",
        "key2": "value2",
        // ... and more key-value pairs.
    },
    // ... and more locales.
}

See the sample used in tests located at: test/fixture/messages.json.

Methods

setMessages

Set messages source. Check messages source format.

var lang = new Lang();
lang.setMessages(source);

getLocale

Get the current locale, if none set, the default locale will be returned (en).

var lang = new Lang();

lang.getLocale();
// > "en"

lang.setLocale('fr');
lang.getLocale();
// > "fr"

setLocale

Set the current locale.

var lang = new Lang();

lang.setLocale('ht');
lang.getLocale();
// > "ht"

getFallback

Get the fallback locale.

var lang = new Lang();

lang.getFallback();
// > undefined

lang.setFallback('de');
lang.getFallback();
// > "de"

setFallback

Set the fallback locale. When retrieving a message (using get() or has()) which is not defined in the specified locale, then it will try to find a message with the fallback locale (if set).

var lang = new Lang({
    messages: {
        'en.greetings': {
            'hi': 'Hi',
            'hello': 'Hello'
        },
        'it.greetings': {
            'hi': 'Salve'
        }
    }
});

lang.setLocale('it');
lang.get('greetings.hello');
// > "greetings.hello"

lang.setFallback('en');
lang.get('greetings.hello');
// > "Hello"

has

Indicate if a given key is defined on the messages source. Return true if the key is defined on the messages source, otherwise false. This method will try to get a message for the specified locale, if not found, then it will return a message for the fallback locale, if not found, then false will be returned.

var lang = new Lang({
    messages: {
        'en.greetings': {
            'hi': 'Hi'
        },
        'es.greetings': {
            'hi': 'Hola'
        }
    }
});

lang.has('greetings.hi');
// > true

lang.has('greetings.hi', 'es');
// > true

lang.has('greetings.hello');
// > false

get

Get a translation message if found, otherwise return the given key. This method will try to get a message for the specified locale, if not found, then it will return a message for the fallback locale, if not found, then the given key will be returned.

var lang = new Lang({
    messages: {
        'en.greetings': {
            'hi': 'Hi'
        },
        'es.greetings': {
            'hi': 'Hola'
        }
    }
});

lang.get('greetings.hi');
// > "Hi"

lang.get('greetings.hi', {}, 'es');
// > "Hola"

lang.get('greetings.hello');
// > "greetings.hello"

Get a translation file from a nested directory

Lang.get('forum/thread.hello');
// > "Hello"

Lang.get('forum/thread.hello', {}, 'es');
// > "Hola"

trans

This method act as an alias of get().

choice

Get the plural or singular form of the message specified based on an integer value.

var lang = new Lang({
    messages: {
        'en.fruits': {
            'apple': 'apple|apples'
        },
        'es.fruits': {
            'apple': 'manzana|manzanas'
        }
    }
});

lang.choice('fruits.apple', 1);
// > "apple"

lang.choice('fruits.apple', 4);
// > "apples"

lang.choice('fruits.apple', 4, {}, 'es');
// > "manzanas"

You may even create more complex pluralization rules which specify translation strings for multiple number ranges:

var lang = new Lang({
    messages: {
        'en.fruits': {
            'apple': '{0} There are none|[1,19] There are some|[20,*] There are many'
        }
    }
});

lang.choice('fruits.apple', 0);   
// > "There are none"

lang.choice('fruits.apple', 1);   
// > "There are some"

lang.choice('fruits.apple', 3);   
// > "There are some"

lang.choice('fruits.apple', 20);   
// > "There are many"

lang.choice('fruits.apple', 22);   
// > "There are many

transChoice

This method act as an alias of choice().

Development

1. Fork this repository and clone it.
2. Create a branch from develop: git checkout -b feature/xxxxxxx
3. Submit a PR to be merge into develop branch.

Get help!

Testing

To run the tests use the following commands:

• Single run: npm run test
• Run on changes: npm run test:watch