Config

 ![npm]()

A configuration file handler. Config can load configuration files from a local file system or a remote server.

Once the config module is initialized you can access config properties as you would a simple POJOs JavaScript object.

Examples

Load a local file

``javascript
const config = require('fwsp-config');
config.init('properties.json')
.then(() => {
console.log(config.aws);
console.log(config.hydra.aws.apiVersions);
});
`

Load a remote file

`javascript
const config = require('fwsp-config');
config.init('http://cjus.me/properties.json');
.then(() => {
console.log(config.aws);
console.log(config.hydra.aws.apiVersions);
});
`

Load from an object

const config = require('fwsp-config');
config.init({
hydra: {
serviceName: 'offers-service',
serviceIP: '',
servicePort: 7000,
serviceType: 'offers',
serviceDescription: 'Phone validation for use with first ride class offers',
redis: {
url: 'redis', port: 6379, db: 15
}
}
})
.then(() => {
console.log(config.hydra);
});
`


Usage

The config module returns a Promise and resolves if it successful loaded and parsed a configuration file, otherwise it rejects. This allows you to sequence application concerns which require configuration data until after the configuration is loaded.

Sharing config files

Sometimes multiple instances of a service might share the same configuration file. To support this use-case, config allows you to define a local configuration file with a location field that specifies the remote location where a configuration file can be found.

`javascript
{
"location": "http://services.com/imageprocesser/properties.json"
}
`

Retrieving a plain JS object

The config module behaves like a JavaScript object once it has configuration files loaded. However, for times when you really do what a pure JS object you can use the getObject() method:

`javascript
const config = require('fwsp-config');
config.init('properties.json')
.then(() => {
let obj = config.getObject();
console.log(JSON.stringify(obj));
});
`

Overriding config properties

Config allows you to use plain JavaScript setter patterns to update a loaded configuration file. This is useful in a shared configuration file scenario where each service loads a config file and needs to override one or more fields.

`javascript
const config = require('fwsp-config');
config.init('properties.json')
.then(() => {
config.hydra.serviceName = 'NewServiceName';
console.log(config.hydra.serviceName);
});
`

Implementation details

This config module is implemented using ES6 Proxy support and so it requires NodeJS 6.2.1 or greater Chrome 49 or greater.

Tests

This project has a series of mocha tests in the specs folder.

To run them you'll need mocha installed:

`shell
$ npm install mocha -g
`

then just:

`shell
$ npm run test
``