Example: Language Resource Bundles

Defining your Custom Module

We use Loader's groups support to add a custom module called "translator" under the group "myapp". The "lang" property in the module's metadata specifies which set of languages it supports.

var appMetaData = {
    myapp: {
        base: '../assets/intl',
        modules : {
            "translator" : {
                path: 'translator/translator.js',
                lang: ["en", "fr", "es"]
            }
        }
    }
};

YUI({
    lang:'fr',
    groups: appMetaData
}).use(...);

NOTE: Since this example is hosted on a page with other YUI instances, we don't want to pollute their configuration, so we just pass our groups: appMetaData configuration property to each YUI instance we create as shown above.

If you own all YUI instances on the page, you can use the global YUI_Config variable to define a global configuration for all YUI instances on the page, to avoid passing the same meta-data to all your instances as shown below:

var YUI_Config = {
    groups: {
        myapp: {
            base: '../assets/intl',
            modules : {
                "translator" : {
                    path: 'translator/translator.js',
                    lang: ["en", "fr", "es"]
                }
            }
        }
    }
};

YUI({
    lang:'fr'
}).use(...);

What Language Resource Bundles Look Like

The language resource bundles for any module follows the pattern below:

YUI.add("lang/translator_fr", function(Y) {

    Y.Intl.add(

        "translator",     // Associated Module
        "fr",             // BCP 47 Language Tag

        {                 // Translated String Key/Value Pairs
            hello:"Bonjour",
            goodbye: "Au revoir"
        }

    );

}, "3.1.0");

The "lang/[for-module]_[lang]" passed to YUI.add is the default module name used for language resource bundles, and the Y.Intl.add method is used to register the string name/value pair hash for a given module and language combination.

Generating Language Resource Bundles

YUI Builder will handle the creation of the boiler plate code shown above, from the raw language files found in the module's src/[module]/lang subdirectory. The raw files under the lang directory contain just the string name/value pairs for each language.

As the component developer, the only thing you need to do is specify the component.lang property in the build properties file:

# In your component's build properties file (src/[module]/build.properties for example):
component.lang=en,fr,es

Provide the raw string name/value pairs in the src/[component]/lang subdirectory in your component's source area:

// Contents of the raw src/[component]/lang/[component]_fr.js file
{
    hello:"Bonjour",
    goodbye: "Au revoir"
}

And whenever you build your component code, the language resource bundles will be built and deployed too.

You can checkout the YUI 3 Source Code and see the source code and build configuration files for the "console" and "datatype-date-format" modules to see a concrete example of this.

Accessing Localized Resources In Your Class

The Translator class implementation gets access to the localized strings by using Y.Intl.get, passing in the module name whose strings we need access to:

function Translator() {
    // Get localized strings in the current language
    this._strs = Y.Intl.get("translator");
}

Translator.prototype = {

    hi : function() {
        return this._strs.hello;
    },

    bye : function() {
        return this._strs.goodbye;
    }

    ...
}

Specifying the Language for an Instance

We specify the language to use for each instance, using the "lang" configuration property for the instance.

An English instance

YUI({
    lang:"en",
    ...
}).use("node-base", "translator", function(Y) {
    var translator = new Y.Translator(),
        out = Y.one("#out");

    say("Speaking in: " + Y.Intl.getLang("translator"), out);
    say(translator.hi(), out);
    say(translator.bye(), out);
});

A French YUI Instance

YUI({
    lang:"fr",
    ...
}).use("node-base", "translator", function(Y) {
    ...
});

A Spanish YUI Instance

YUI({
    lang:"es",
    ...
}).use("node-base", "translator", function(Y) {
    ...
});

Modules Shipping With Language Resource Bundles

As mentioned above, the datatype module (specifically the datatype-date-format module) and console are shipped with language resource bundles. Datatype ships with over 50 different languages supported, and Console ships with en and es language resource bundles, mainly as a demonstration of how language resource bundles are defined and used for Widget development.

Complete Example Source

<div id="out"></div>

<script>
(function() {

    var say = function(msg, node, cls) {
        node.append('<p class="' + cls + '">' + msg + '</p>');
    };

    var appMetaData = {
        myapp: {
            base: '../assets/intl/',
            modules : {
                "translator" : {
                    path: 'translator/translator.js',
                    lang: ["en", "fr", "es"]
                }
            }
        }
    };

    YUI({
        lang:"en",
        groups: appMetaData
    }).use("node-base", "translator", function(Y) {
        var translator = new Y.Translator(),
            out = Y.one("#out");

        say("Speaking in: " + Y.Intl.getLang("translator"), out, "speaking");
        say(translator.hi(), out, "word");
        say(translator.bye(), out, "word");
    });

    YUI({
        lang:"fr",
        groups: appMetaData
    }).use("node-base", "translator", function(Y) {
        var translator = new Y.Translator(),
            out = Y.one("#out");

        say("Speaking in: " + Y.Intl.getLang("translator"), out, "speaking");
        say(translator.hi(), out, "word");
        say(translator.bye(), out, "word");
    });

    YUI({
        lang:"es",
        groups: appMetaData
    }).use("node-base", "translator", function(Y) {
        var translator = new Y.Translator(),
            out = Y.one("#out");

        say("Speaking in: " + Y.Intl.getLang("translator"), out, "speaking");
        say(translator.hi(), out, "word");
        say(translator.bye(), out, "word");
    });

}());
</script>