Introduction

enum-i18n extends the excellent enum implementation adrai/enum. It exposes an Enum constructor that can be configured with a translate function.

Installation

npm install -S enum-props

Usage

This document addresses the i18n features added here. For full documentation see adrai/enum.

Constructor Factory

The default export of this module is a factory that returns partially configured Enum constructors. You can pass any config values supported by adrai/enum and they will be used for any enumerations instantiated with the returned constructor.

var enumI18n = require( "enum-i18n" );
var FrozenEnum = enumI18n( { freez: true } ); // Constructor for readonly enums
var InsensitiveEnum = enumI18n( { ignoreCase: true } ); // Constructor for case insensitive enums

Translate Functions

Every enumeration must be provided a translate function. This function will be called to get a plain-text description of each enum member. A translate function will be passed an enum member and is expected to return a string.

You can pass a translate function to the constructor factory:

var Enum = require( "enum-i18n" )( {
    translate: function( member ) {
        return getTranslation( "enums." + member.enum.name + "." + member.key );
    }
} );

// Same as this shorthand:
var Enum = require( "enum-i18n" )( function( member ) {
    return getTranslation( "enums." + member.enum.name + "." + member.key );
} );

Or you can pass a translate function to the constructor:

var Enum = require( "enum-i18n" )();
var colors = new Enum( [ "red", "yellow", "green" ], {
    name: "colors",
    translate: function( member ) {
        return member.key;
    }
} );

If you pass both then the constructor's translate function will win.

Enum Construction

Every enumeration must be provided with a name and a translate function. The name must be provided at the time the enumeration is instantiated.

var Enum = require( "enum-i18n" )( translator );
var colors = Enum( [ "red", "yellow", "green" ], {
    name: "colors"
} );

// Same as shorthand:
var colors = Enum( [ "red", "yellow", "green" ], "colors" );

You can also pass any options supported by adrai/enum.

Example (shared translation set)

If you have a single translation collection for your app, you can pass a translate function in the enum-i18n options:

// Pass config and get back an Enum constructor
var Enum = require( "enum-i18n" )( function( member ) {
    // Return a string to use as the enum member's description
    return getTranslation( "enums." + member.enum.name + "." + member.key );
);

// Define a simple enum
var colors = new Enum( [ "red", "yellow", "green" ], "colors" );

// Render the member keys/values/descriptions
colors.enums.map( function( member ) {
    return member.key + ", " + member.value + ", " + member.toDescription();
} );
/*
[
    "red, 1, enums.colors.red",
    "yellow, 2, enums.colors.yellow",
    "green, 4, enums.colors.green"
]
*/

Example (independent translation sets)

If you have a translation collection per enumeration, you can pass a translate function in the constructor options:

// Pass config and get back an Enum constructor
var Enum = require( "enum-i18n" )();

var COLOR_NAMES = {
    red: "stop",
    yellow: "caution",
    green: "go"
};

// Define a simple enum
var colors = new Enum( [ "red", "yellow", "green" ], {
    name: "colors",
    translate: function( member ) {
        // Return a string to use as the enum member's description
        return COLOR_NAMES[ member.key ];
    }
} );

// Render the member keys/values/descriptions
colors.enums.map( function( member ) {
    return member.key + ", " + member.value + ", " + member.toDescription();
} );
/*
[
    "red, 1, stop",
    "yellow, 2, caution",
    "green, 4, go"
]
*/

Development

npm test # run tests
gulp coverage # run tests with linting and coverage
gulp show-coverage # show coverage full report
gulp # build compiled lib