Localization Plugin for Catberry Framework

Installation

npm install catberry-l10n --save

Description

This plugin adds localization support for Cat-components.

It supports two contexts of localization:

1. Application-based localization - files like en.json, en-us.json, en-gb.json and etc. inside the l10n directory at the root of your application
2. Component-based localization - the same as above but l10n directory should be placed inside a component's directory

Every localization file is a dictionary of key value pairs. Keys are called "localization keys" and values are strings in specified language or arrays with plural forms.

For example, your project tree can look like this:

catberry_components
    component1/
        l10n/
            en.json
            en-us.json
            en-gb.json
            ru.json
        ...
    component2/
        l10n/
            en.json
            en-us.json
            en-gb.json
            ru.json
        ...
l10n/
    en.json
    en-us.json
    en-gb.json
    ru.json

Your application-based localization directory should always have a default localization file and a default locale name should be set in a Catberry application's config, for example:

{
    l10n: {
        // default locale used when value for specified locale not found
        // this parameter is required
        defaultLocale: 'en-us',
        // display keys of not founded localization strings
        placeholder: false,
        cookie: {
            // name of locale cookie (Optional, 'locale' by default)
            name: 'locale',
            // max cookie age (Optional, 100 years by default)
            maxAge: 3155692600,
            // cookie path (Optional, empty by default)
            path: '/',
            // cookie domain (Optional, empty by default)
            domain: 'some.domain.org'
        }
    },
    someOtherParameter: 'someOtherValue'
}

It means that l10n/en-us.json file is required at the root of your application.

While localization file is being loaded it is merged with the default localization dictionary adding absent keys. Localization of components is overriding application-based localization values if they have matching keys. If localization set specified by user does not have the localization key then value from the default localization set is returned or empty string if default localization also does not have such key.

Usage

To use the localization plugin you should register its components into Catberry's Service Locator like this:

In server.js

const l10n = require('catberry-l10n');
const catberry = require('catberry');
const config = require('./config-server');
const app = connect();
const cat = catberry.create(config);

// register localization components as singletons
l10n.register(cat.locator);

// then resolve loader to get middleware
const localizationLoader = cat.locator.resolve('localizationLoader');

// use middleware to setup locale in user's cookie
// and get /l10n.js file for user's locale
app.use(localizationLoader.getMiddleware());

// localization middleware should be before Catberry
app.use(cat.getMiddleware());
...

In browser.js/build.js

const l10n = require('catberry-l10n');
const catberry = require('catberry');
const config = require('./config-client');
const cat = catberry.create(config);

// register localization components in locator
l10n.register(cat.locator);

As you might notice, catberry-l10n has a server-side middleware that automatically sets a browser's locale to the user's cookie and you can use this value from $context.cookie.get in your stores and components.

Also, you should include /l10n.js script into your HEAD element. This URL is served by catberry-l10n middleware.

Pluralization

Pluralization support was implemented using these rules. For pluralization of localized value, it should be set as an array with all required plural forms for locale's language.

How to use

Localization dictionary:

{
    "EAT": "eat",
    "APPLE": ["%d apple", "%d apples"]
}

Component code:

class Component {
    constructor(locator) {
        this._l10n = locator.resolve('localizationProvider');
    }

    render() {
        // user always has locale in context (thanks to l10n middleware)
        const locale = this._l10n.getCurrentLocale(this.$context);
        const appleCount = Number(this.$context.state.apples);
        return {
            localizedEat: this._l10n.get(locale, 'EAT'),
            localizedApple: util.format(
                this._l10n.pluralize(locale, 'APPLE', appleCount),
                appleCount
            )
        };
    }
}

Component's template (using Dust for example):

{localizedEat} {localizedApple}

For 1 apple it will be eat 1 apple

For 5 apples it will be eat 5 apples

Also, you can change current locale using changeLocale method of localizationProvider like this:

this._l10n.changeLocale('en-gb', this.$context);

it changes the locale value in cookie and reloads the page.

Contributing

There are a lot of ways to contribute:

• Give it a star
• Join the Gitter room and leave a feedback or help with answering users' questions
• Submit a bug or a feature request
• Submit a PR

Denis Rechkunov denis@rdner.de