EXT DI (EXT Dependency Injector)

Features

• simple dependency injection helper module
• let's you write unit-testable code
• simple access to your dependency - all dependencies can be accessed via the injector: createdClassInstanceByInjector.ext.get(dependencyModule)

Usage

Firstly, install it:

npm install ext-di --save

Use it like this

const Injector = require('ext-di');
let injector = new Injector({ 'redis' : { module : 'ioredis', className : 'Redis' }});

API

constructor(config)

• config.ALIAS_NAME The alias name for the class/module
• config.ALIAS_NAME.module This value will be used for 'require'
• config.ALIAS_NAME.className The actual class name ( leave empty if not used )
• config.ALIAS_NAME.params The list of params for this instance of the class ( leave empty if not used )
• config.ALIAS_NAME.instantiate Should the injector create a new instance of the 'class' ( leave empty if not used )

Options	Effect
{"alias": "fs"}	This will directly use the given module
{"alias": {"module": 'm'}}	require('m')
{"alias": {"module": "m", "instantiate": true}}	new require('m')()
{"alias": {"module": 'm', "className": 'C'}}	require('m').C
{"alias": {"module": "m", "className": 'C', "instantiate": true}}	new require('m').C()

get(aliasName)

• aliasName string The alias name for the class. It will be instantiated using the configured params

/** complex.js **/
class Complex {

    async getNr() {
        let nativeService = await this.getService('native');
        return nativeService.nr;
    }

}

/** native.js **/
module.exports = {
    nr: 123456
};

/** index.js **/
let injector = new Injector({
    'complex': {module: 'complex.js', className: 'Complex', instantiate: true},
    'native': {module: 'native.js'}
});

let complex = await injector.get('complex');
complex.getNr();