Configurable plugin to determine request language in hapi.js applications.

This plugin determines requested loclale by looking at the following: (Order can be changed or skipped via options.order)

• URL parameter,
• Cookie,
• Query parameter,
• HTTP header.

Optionally creates getter and setters or uses already available ones in request. Calls setter method with requested locale. Also provides plugin methods such as server.plugins['hapi-locale'].getLocale();

Nearly every aspect of the plugin can be configured with options. Sensible defaults are tried to be provided.

Create server

...
var plugins = [{ 
    register: 'hapi-locale'
    options: {
        createAccessors: true,
        getter: 'i18n.getLocale',
        setter: 'i18n.setLocale'
    }
}]
...
server.register(plugins, function (err) {
    if (err) throw err;
    server.start(function () {
        console.log('Server started at: ' + server.info.uri);
    });
});

In handlers:

var locale = request.i18n.getLocale();

It is easy to determine locale in hapi.js. So why is this plugin written? We are tired of writing repetitive code for every application/module and decided to export this functionality as a hapi plugin.

Also we make it tested and documented.

The options below are the most important ones, because they change/write the request object and may cause undesirable results if not properly configured to suit your needs.

Please see all options below in hapiLocale~PluginOptions in API section

The workflow of the plugin is as below:

Plugin

1. Determines which locales are available in application. This happens one time during plugin registration.
2. Tries to find which locale is prefered looking incoming request. This and other steps below happen in every request. Event for this step is configured by options.onEvent
3. Matches requested locale with available locales. If no match is found: a. If options.throw404 is true and URL param has a locale which is not available. b. Sets default locale.
4. (Optional) Adds getter and setter methods in request object. By deafult request.i18n.getLocale and request.i18n.setLocale.
5. Setter is called.

Available locales are determined with methods in the following order. If one of the methods succeeds no other methods are tried. One or more steps may be cancelled via options. Available locales are searched one time during plugin registration.

Plugin

1. Looks locales up in plugin options options.locales. Set empty [] to skip.
2. Looks package.json or other json file set by options.configFile and options.configKey. Key may be set with nested format such as 'pref.of.my.app.locales'. Set null to skip.
3. Scans path given by options.scan.path excluding files and directories given by options.path.exclude. Set null to skip.

One or more locale may be preferred in requests. To determine the most wanted locale for every request the following steps are taken in order set by options.order. One or more steps may be cancelled via setting null in related options or not including to options.order.

Plugin (in default order, which can be changed from options.order)

1. params looks path paramater such as {lang}/member for /en_US/member. Path parameter name can be set via options.param.
2. cookie looks cookie. Cookie name can be set via options.cookie, cookie key to look in cookie can be set options.cookieKey.
3. query looks query paramater such as /member?lang=en_US. Query parameter name can be set via options.query.
4. header looks accept-language header of request. Header name can be set via options.header.

Plugin tries to find first preferred locale which is available in application:

1. If a match is found, locale is determined.
2. If no match is found plugin either throws 404 for URL parameter if options.throw404 set true.
3. If no 404 is thrown, default locale is used as a result. Default locale may set via options.default, otherwise first available locale is used as default.

Plugin uses getter and setter methods. It creates them if options.createAccessors is true and they do not exist. Name of the methods are set via options.getter and options.setter options. Default values are i18n.getLocale and i18n.setLocale.

Callback is called with locale name as only parameter. Callback name is configured via options.callback. If callback name is given as a function reference, it is called directly. If it is given as string it is called as a chained method of request object. Default is "i18n.setLocale" which results as request.i18n.setLocale. It is possible to use a chained method name such as "i18n.setLocale" which results as request.i18n.setLocale.

By default this plugin looks URL Part (request.params), Cookie (request.state), Query String (request.query), Header (request.headers) in this order: 'params', 'cookie', 'query', 'headers'. If you wish to change this order you can set it with options.order array.

Available locales are determined one time during server start plugin registration. Per request operations happens on event set by options.onEvent.

This plugin exposes some functions and attributes using server.expose mechanism of hapi.js. They are documented under API section's exposed part. See there for details.

// This function may be used to access requested locale manually.
var locale  = request.server.plugins['hapi-locale'].getLocale(request, reply); // 'tr_TR'
    
var locales = request.server.plugins['hapi-locale'].getLocales();   // ['tr_TR', 'en_US'] etc.

var server  = new hapi.Server(),
    path    = require('path');

server.connection({
    host: 'localhost',
    port: 8080
});

var plugins = ['hapi-locale']

server.route([
    {
        path: "/locale",
        method: "GET",
        handler: function(request, reply) {
            reply({ locale: request.i18n.getLocale() });    // This method is added by hapi-locale
        }
    },
    {
        path: "/{lang}/locale",
        method: "GET",
        handler: function(request, reply) {
            reply({ locale: request.i18n.getLocale() });    // This method is added by hapi-locale
        }
    }
]);


server.register(plugins, function (err) {
    if (err) throw err;
    server.start(function () {
        console.log('Server started at: ' + server.info.uri);
    });
});

Options below are also default options.

var server  = new hapi.Server(),
    path    = require('path');

server.connection({
    host: 'localhost',
    port: 8080
});

var rootDir = __dirname;

// Those are also default options:
var plugins = [
    {
        register: 'hapi-locale',
        options: {
            locales         : [],
            configFile      : path.join(rootDir, 'package.json'),
            configKey       : 'locales',
            scan            : {
                path        : path.join(rootDir, 'locales'),
                fileType    : 'json',
                directories : true,
                exclude     : ['templates', 'template.json']
            },
            param           : 'lang',
            query           : 'lang',
            cookie          : 'lang',
            cookieKey       : 'lang',
            header          : 'accept-language',
            order           : ['params', 'cookie', 'query', 'headers'],
            throw404        : true,
            getter          : 'i18n.getLocale',
            setter          : 'i18n.setLocale',
            createAccessors : true,
            attribute       : 'i18n.locale',
            callback        : 'setLocale',
            onEvent         : 'onPreAuth'
         }
    }
];

server.route([
    {
        path: "/locale",
        method: "GET",
        handler: function(request, reply) {
            reply({ locale: request.i18n.getLocale() });    // This method is added by hapi-locale
        }
    },
    {
        path: "/{lang}/locale",
        method: "GET",
        handler: function(request, reply) {
            reply({ locale: request.i18n.getLocale() });    // This method is added by hapi-locale
        }
    }
]);


server.register(plugins, function (err) {
    if (err) throw err;
    server.start(function () {
        console.log('Server started at: ' + server.info.uri);
    });
});

'hapi-locale'

Configurable plugin to determine request language in hapi.js applications.

exposed

Exposed functions and attributes are listed under exposed name. To access those attributes request.server.plugins['hapi-locale'] can be used.

• 'hapi-locale'
  • static
    • .register(server, options, next)
  • inner
    • ~PluginOptions : Object

Hapi plugin function which adds i18n support to request and response objects.

Kind: static method of 'hapi-locale'

Plugin configuration options.

Kind: inner typedef of 'hapi-locale'
Properties

Exposed functions and attributes are listed under exposed name. To access those attributes request.server.plugins['hapi-locale'] can be used.

Example

var locales = request.server.plugins['hapi-locale'].getLocales(); // ['tr_TR', 'en_US'] etc.

• exposed
  • ~getLocales() ⇒ Array.<string>
  • ~getDefaultLocale() ⇒ string
  • ~getLocale(request) ⇒ string

Returns all available locales as an array.

Kind: inner method of exposed
Returns: Array.<string> - - Array of locales.
Example

var locales = request.server.plugins['hapi-locale'].getLocales(); // ['tr_TR', 'en_US'] etc.

Returns default locale.

Kind: inner method of exposed
Returns: string - - Default locale

Returns requested language.

Kind: inner method of exposed
Returns: string - Locale

Note: Simple documentation updates are not listed here.

• Changed: node.js 4 (ES6) is used.
• Some changes are incompatible with 0.x versions.
• Changed: Internal structure of the plugin is completly changed. It is class based now.
• Added: JOI validations for plugin options.
• Changed: Code cleaned up to make it easily understandable.
• Changed: Documentation is updated.
• Changed: Option names are simplified.
• Changed: options.throw404 only affects URL parameter now.
• Changed: options.callback is not used anymore. options.setter is used both as a setter and as a callback.
• Changed: Best match algorithm now tries every method until requested language is one of the available ones.

• Fixed: Accept language header parsed wrong.

• Changed: Tests ported from Mocha/Chai to Lab/Code.
• Fixed: Created setter function does not work.

• Changed: options.createGetterOn and options.createSetterOn are renamed as options.getter and options.setter.
• Added: options.createAccessorsIfNotExists added.
• Fixed: Wrong path parameter caused reply called twice. Fixed.

• Added: Cookie support. options.order to change order of process to determine locale. It is possible to proritize query etc. over url parameters now.

• Changed: options.createGetter and options.createSetter are renamed as options.createGetterOn and options.createSetterOn

• Added: getDefaultLocale() exposed function.

• Added: getLocale() and getLocales() exposed functions.

• Initial version.

The MIT License (MIT)

Copyright (c) 2015 Özüm Eldoğan

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.