nali

a service registry for dependency injection and application composition

usage

const nali = require('nali')

// we can register services
// type Service: (...) => Instance
// Services are functions with
// optional dependency names as parameters
// and which return an initialized instance of itself
// the return value can be a Promise or a Value
nali.register({
  config: function () {
    return P
    conn_str: 'http://foo.bar'
  },
  db: function (config) {
    return Doodaboos.connect(config.conn_str)
  
  })

// we can resolve an instance of our `db` service:

nali.resolve('db').then(function (db) {
  // now we can do stuff with our db service
})

nali will fetch or lazily instantiate arbitrary trees of service dependencies.

api

nali(name: String) => service:any

(alias: nali.fetch)

Synchronously fetch a service instance

Can also be used to asynchronously resolve multiple dependencies, for example:

nali(function (db, log, sessions, webService) {
  // now we have all the things
})

nali.resolve(name: String) => Promise<service: Any>

Asynchronously resolve an instance of a service, lazily instantiating any dependencies if necessary

nali.registerInstance(name: String, instance: Object) => void

deprecated use nali.register('name', () => instance) instead

nali.registerService(name: String, service: Service) => void

deprecated use nali.register('name', service) instead

Service Dependencies

DI works similar to Angular. Service init functions state the names of their dependencies as parameter names, which are parsed out when the Service is registered. They are not called with new or with any particular this context.

Return a Promises/A+ promise if you need to asynchronously instantiate a service

Resolution algorithm

Work in progress.

Try get local instance Try get new instance of local service Try get parent instance Try get new instance of parent service Etc

not implemented

• scopes
• disposing instances / lifecycle management
• anything else

installation

$ npm install nali

running the tests

From package root:

$ npm install
$ npm test

contributors

• jden [email protected]

license

MIT. (c) MMXV AgileMD. See LICENSE.md