decorators.md

Decorators

Creating service definition via container (definitionWithConstructor etc) might be a tedious and error-prone work. That's why alpha-dic supports decorators for classes.

NOTE! Hopefully this is obvious but Decorators are not supported by node.js natively. You need to use Typescript (highly recommended) or other transpiler (like Babel) to make it work.

const {Service, Annotation, Inject} = require('alpha-dic');

@Service() // you can also provide a name @Service('name'). By default class/function name inferred.
@Annotation({name: 'extraAnnotation'})
export class NotificationCenter {
    
    @Inject('superExtraService')
    public extraService: ExtraService;
    
    constructor(
        @Inject('EmailRenderer') emailRenderer: EmailRenderer, 
        @Inject('EmailSender') emailSender: EmailSender) {
    }
}

Setup

Since decorator is just regular function you need to give it an opportunity to get called. To do soo you can use loadServices function that loads all modules matching given patterns.

import {createStandard, loadServices} from 'alpha-dic';

const container = createStandard();

// loads all files (with extensions .ts, .js, .tsx but ignores .d.ts, .d.tsx) in given directory so all @Service decorator calls got a chance to register service definitions
loadServices(container, {
    patterns: './services/*.*' // note ".*" to make sure glob can catch all files
});