GalacticJS

GalacticJS is a framework for building and running pluggable architectures in JavaScript. It allows you to keep configuration manageable in one central place, while the framework deals with wiring up the correct dependencies and pushing updates throughout the application.

:warning: Currently a development snapshot only; use with care!

Features

• Advanced dependency injection (DI) framework with support for constructor injection and multi-injection
• Dependencies are hot-swappable, meaning that changes to your configuration become effective immediately.
• Rich and effectve interactive command-line tool for changing the state of your application on-the-fly.

How it works

Conceptually, GalacticJS generates a complete graph of how your application components are wired and then calculates the difference between the current wiring graph and the previous one. It then swaps, injects and removes components where needed.

Example

First make sure you have TypeScript installed and experimentalDecorators is set to true in your tsconfig.json.

tsconfig.json

{
  "compilerOptions": {
    "module": "commonjs",
    "target": "es6",
    "experimentalDecorators": true
  }
}

The following code snippet demonstrates how you can define a knight, which can yield different types of weapons based on some configuration.

example.ts

import { detail, provide, inject } from "galacticjs"

interface Weapon {
  hitPoints: number;
}

@provide('weapon')
@detail({ weaponType: 'sword' })
export class Sword {
  hitPoints = 7; 
}

@provide('weapon')
@detail({ weaponType: 'crossbow' })
export class Crossbow {
  hitPoints = 5;
}

@provide('knight')
export class Knight {

  @inject('weapon')
  weapon: Weapon;

}

You can run this application after compiling with the command $ galactic example.js. If you run $ galactic --interactive example.js, you will be provided with a minimal command-line interface in which you can change the configuration while your application is running.

> set weaponType sword
> set weaponType boo!
Error: invalid configuration.
No dependency satisfied for Knight.weapon
> get weaponType
sword
> services
- knight (Knight)
- weapon (Sword)

The default dependency resolver will resolve when the details provided to individual objects are a partial of the full configuration object, which isn't very flexible. Therefore, GalacticJS allows defining custom resolvers that map specific configurations to specific dependencies.

@resolve("weapon")
export class WeaponResolver {
  resolve(config, detail) {
    return config.isRanged && detail.weaponType === 'crossbow'
        || !config.isRanged && detail.weaponType === 'sword'
  }
}

License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.