koa-locales

koa locales, i18n solution for koa:

1. All locales resources location on options.dirs.
2. resources file supports: *.js, *.json, *.yml, *.yaml and *.properties, see examples.
3. Api: __(key[, value, ...]), __n(key, count[, value, ...]).
4. Auto detect request locale from query, cookie and header: Accept-Language.

Installation

$ npm install koa-locales --save

Quick start

const koa = require('koa');
const locales = require('koa-locales');

const app = koa();
const options = {
  dirs: [__dirname + '/locales', __dirname + '/foo/locales'],
};
locales(app, options);

API Reference

locales(app, options)

Patch locales functions to koa app.

• {Application} app: koa app instance.
• {Object} options: optional params.
  • {String} functionName: locale function name patch on koa context. Optional, default is __.
  • {String} functionnName: locale function (with plurals management) name patch on koa context. Optional, default is __n.
  • {String} dirs: locales resources store directories. Optional, default is ['$PWD/locales'].
  • {String} defaultLocale: default locale. Optional, default is en-US.
  • {String} queryField: locale field name on query. Optional, default is locale.
  • {String} cookieField: locale field name on cookie. Optional, default is locale.
  • {String} cookieDomain: domain on cookie. Optional, default is ''.
  • {Object} localeAlias: locale value map. Optional, default is {}.
  • {String|Number} cookieMaxAge: set locale cookie value max age. Optional, default is 1y, expired after one year.

locales({
  app: app,
  dirs: [__dirname + '/app/locales'],
  defaultLocale: 'zh-CN',
});

Aliases

The key options.localeAlias allows to not repeat dictionary files, as you can configure to use the same file for es_ES for es, or en_UK for en.

locales({
  localeAlias: {
    es: es_ES,
    en: en_UK,
  },
});

context.__(key[, value1[, value2, ...]])

Get current request locale text.

async function home(ctx) {
  ctx.body = {
    message: ctx.__('Hello, %s', 'fengmk2'),
  };
}

Examples:

__('Hello, %s. %s', 'fengmk2', 'koa rock!')
=>
'Hello fengmk2. koa rock!'

__('{0} {0} {1} {1} {1}', ['foo', 'bar'])
=>
'foo foo bar bar bar'

__('{a} {a} {b} {b} {b}', {a: 'foo', b: 'bar'})
=>
'foo foo bar bar bar'

context.__n(key, count[, value1[, value2, ...]])

Get current request locale text with plural.

Works with package make-plural package. Support approximately 200 languages.

async function home(ctx) {
  ctx.body = {
    message: ctx.__n({one: 'I have one apple.', other: 'I have {0} apples.', 2, 2),
  };
}

Note:
The count parameter is not part of the displayed values. To have the number count displayed, one must add this parameter to the list of values.

Examples:

// With english locale
__n({one: 'I have one cat.', other: 'I have not one cat.'}, 0)
=>
'I have not one cat.'

// With french locale
// Note that the parameter 0 is put two times:
// The first one is used as the count parameter and the second is displayed as
// first value ({0}).
__n({one: "J'ai {0} chat.", other: "J'ai {0} chats."}, 0, 0)
=>
"J'ai 0 chat."

// If the targeted plural is not found (here 'one'), 'other' is selected.
__n({other: '{a} {a} {b} {b} {b}'}, 1, {a: 'foo', b: 'bar'})
=>
'foo foo bar bar bar'

Russian json file (from i18n example):

{
  "cat_key": {
    "one": "%d кошка",
    "few": "%d кошки",
    "many": "%d кошек",
    "other": "%d кошка",
  }
}

Use:

__n('cat_key', 0, 0);
=>
'0 кошек'

__n('cat_key', 1, 1); 
=>
'1 кошка'

__n('cat_key', 2, 2);
=>
'2 кошки'

__n('cat_key', 5, 5); 
=>
'5 кошек'

__n('cat_key', 6, 6);
=>
'6 кошек'

__n('cat_key', 21, 21);
=>
'21 кошка'

context.__getLocale()

Get locale from query / cookie and header.

context.__setLocale()

Set locale and cookie.

context.__getLocaleOrigin()

Where does locale come from, could be query, cookie, header and default.

app.__(locale, key[, value1[, value2, ...]])

Get the given locale text on application level.

console.log(app.__('zh', 'Hello'));
// stdout '你好' for Chinese

Usage on template

this.state.__ = this.__.bind(this);

Nunjucks example:

{{ __('Hello, %s', user.name) }}

Pug example:

p= __('Hello, %s', user.name)

Koa-pug integration:

You can set the property locals on the KoaPug instance, where the default locals are stored.

app.use(async (ctx, next) => {
  koaPug.locals.__ = ctx.__.bind(ctx);
  await next();
});

app.__n(locale, key, count[, value1[, value2, ...]])

Get the given locale text with plural management on application level.

console.log(app.__n('zh', {other: 'Hello'}, 0));
// stdout '你好' for Chinese

Usage on template

this.state.__n = this.__n.bind(this);

Nunjucks example:

{{ __n({other: 'Hello, %s'}, 2, user.name) }}

Pug example:

p= __n({other: 'Hello, %s'}, 2, user.name)

Koa-pug integration:

You can set the property locals on the KoaPug instance, where the default locals are stored.

app.use(async (ctx, next) => {
  koaPug.locals.__n = ctx.__n.bind(ctx);
  await next();
});

Debugging

If you are interested on knowing what locale was chosen and why you can enable the debug messages from debug.

There is two level of verbosity:

$ DEBUG=koa-locales node .

With this line it only will show one line per request, with the chosen language and the origin where the locale come from (queryString, header or cookie).

$ DEBUG=koa-locales:silly node .

Use this level if something doesn't work as you expect. This is going to debug everything, including each translated line of text.

License

MIT