config-js

config.js

A config utility for node.js, that uses a single JavaScript file with an export JavaScript object. After loading the JavaScript object from the configuration file, all properties are set constant, preventing changes. However, if the file is changed on disk, it is automatically reloaded.

There is support for environment targets. If you have the environment variable NODE_ENV set and you have '##' in your file path, config.js substitutes the '##' with the contents of NODE_ENV and then loads that file. If you have a file named ./conf/app_PRODUCTION.js, you would load it like so:

process.env.NODE_ENV = 'PRODUCTION';
var Config = require('config-js');
var config = new Config('./conf/app_##');

config.js uses "have" to validate arguments passed to it. If you pass incorrect arguement types, have will throw. You should not wrap your calls in try/catch handlers, but test the inputs you are using. The logic is, if you are not passing the correct types, it's a bug to fix not a run-time situation to handle.

Features

• Support for multiple configuration files using NODE_ENV
• Support for an optional defaults file that is overritten by target config
  • The file, defaults.js must be next to the target config file(s)
• Configurable separation character to specify value in object path
• If an ENVIRONMENT variable exists in all upper case with the sep character relpaced by underscores, e.g. _ Then the environment variable overrides any values in the configuration files.
• On a get, if there is no matching environment variable, no config file value, default config value, or default agrgument, the function throws.

Installation

$ npm install config-js

Examples

The configuration file should export an object via module exports as seen in the following example:

module.exports = {

    logging : {
        level: 'info',              // INFO logging level
        name: 'mush.js',            // Category name for logging
    },

    server : { port : 4201 }
};

Using the above configuration file, the following code will not throw an exception:

var Config = require('config-js');
var config = new Config('./test/cfg_example.js');
assert.ok(config.get('server.port') === 4201);
assert.ok(config.get('logging.name') === 'mush.js');
// test default value
assert.ok(config.get('No.Such.Value.Exists', 511) === 511);
assert.ok(config.setSepChr('/') === true);
assert.ok(config.get('server/port') === 4201);
assert.ok(config.get('logging/name') === 'mush.js');

Additionally, the configuration file can have regions:

module.exports = {

    en: {
        welcome: "Welcome to this file."
    },

    de: {
        welcome: "Willkommen zu dieser datei."
    },

    es: {
        welcome: "Bienvenidos a este archivo."
    }
};

The regions can be used with the getByRegion method:

// if no region is specified, 'en' is assumed.
assert.ok(config.getByRegion('welcome') === 'Welcome to this file.');

// You can change the above assumption in the constructor
config = new Config('./test/cfg_example2.js', 'de');
assert.ok(config.getByRegion('welcome') === 'Willkommen zu dieser datei.');

// the get method can still be used
assert.ok(config.get('de.welcome') === 'Willkommen zu dieser datei.');

// and you can always specify the region
assert.ok(config.getByRegion('welcome', 'es') === 'Bienvenidos a este archivo.');

API

Config(pathToConfigFile [, region])

Config provides a simple read-only API to a configuration object.

Params:

• String pathToConfigFile The configuration file
• String [region] An optional indicator for the current region (e.g. 'US','JP').

loadConfig(pathToConfigFile)

Loads the configuration from the location specified by the parameter.

Params:

• string pathToConfigFile The file name path to the configuration file.

get(propertyName [, defaultValue] [, sepChr])

Return the value associated with the specified property. If no such property is found, the provided defaultValue will be returned or undefined if no defaultValue was provided.

Params:

• string propertyName The name of the property to look for. May include '.' characters indicating an object traversal (e.g. 'parent.child.age', 'parent').
• string defaultValue A default value to use in case no property having propertyName was found.
• string sepChar Change the default separator character in the path from '.' to whatever you want.

Returns:

• The value found, if no value is found, then the default value. If there is no default value then undefined.

getByRegion(propertyName [, defaultValue] [,sepChar])

Return the region-specific value associated with the specified property. If no such property is found, the provided defaultValue will be returned or undefined if no defaultValue was provided. The region should be provided in the constructor to this object. If no region was specified when this object was created, the defaultValue will be returned.

Params:

• String propertyName The name of the property to look for. May include '.' characters indicating an object traversal (e.g. 'parent.child.age', 'parent').
• String defaultValue A default value to use in case no property having propertyName was found.
• string sepChar Change the default separator character in the path from '.' to whatever you want.

Returns:

• The value found, if no value is found, then the default value. If there is no default value, then undefined.

setSepChr(chr)

Change the default separator character from '.' to whatever character you want.

Params:

• string chr The new default separator character in the path.

Returns:

• {Boolean} True if the value was set and false otherwise.

License

The MIT License (MIT)

Copyright (c) 2013,2014 Edmond Meinfelder

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.