node-service-locator

node-service-locator
====================

service locator for node js

Allow to load instanse of service with injected dependency of other service. Service dependencies are described in declarative way. Locator is a singletone so you can register services ones and then use it everywhere in your app

##Install
``
npm install node-service-locator
`

##Usage

$3

Lets assume that we have a folder 'Services' in project and and file Logger with logger service in it.
`javascript
// Services/Logger.js

exports.log = function (msg) {
console.log(msg);
};

`

Service description example

`javascript
// services.js file

module.exports = {
"logger": {
"path": "Services/Logger"
}
}
`

Usage Example
`javascript
var serviceList = require('./services');

var basePath = __dirname;

var locator = require('node-service-locator');
locator.init(serviceList, basePath);

//load simple object
var logger = locator.get('logger');
`




$3


`javascript
// Services/ClassLogger.js

var ClassLogger = function (errorLevel) {
this.level = errorLevel || "debug";
};

ClassLogger.prototype.log = function(message) {
console.log(this.level, message);
};

module.exports = ClassLogger;

`

In order to return from locator an instance of this service you should add instantiate and parameters keys to service description

`javascript
"warningLogger": {
"path": "Services/ClassLogger",
"instantiate": true,
"params": ["warning"]
}
`
And than in you app:
`javascript
var warningLogger = locator.get('warningLogger');

warningLogger.log('Alarm!');

`

Also you have possibility to pass one service as a parameter to anather to do this add '@' to service name in the params field

`javascript
"ClassWithWarningLogger": {
"path": "Services/ClassWithWarningLogger",
"instantiate": true,
"params": ["foo", "@warningLogger", 23]
}
`

Also you can register some services on th fly
`javascript
locator.register('foo', {name: 'foo'});

console.log(locator.get('foo').name);
// => foo
`

###Invoke some function with services as parameters

`javascript
locator.register('foo', {name: 'foo'});

locator.invoke('foo', 'logger', function (foo, logger) {
logger.log(foo.name);
});


// => foo
``

##LICENSE
MIT

More examples in example folder