madig

Madig

Madig is a Javascript dependency injection engine.

Installation

npm add madig

Usage

Create configuration

Injectable configuration object needs to respect the following format :

[{
  class: ClassFile, // the class to instanciate
  dependsOn: [Dep1ClassFile, Dep2ClassFile] // the classes to inject in the constructor
}]

Module injection

In addition to classes, it is possible to inject modules into the class constructor. To do this, declare the dependency as follows.

[{
  class: ClassFile, // the class to instanciate
  dependsOn: [{name: 'MyModule', MyModule}] // the module to inject in the constructor
}]

Example :

const Madig = require('madig');

// Create new injectable configuration
const madig = new Madig([
  {
    class: TodoController,
    dependsOn: [TodoService],
  },
  {
    class: TodoService,
    dependsOn: [TodoRepository, { name: 'ModuleHelloBis', ModuleHelloBis }],
  },
  {
    class: TodoRepository,
    dependsOn: [Db, { name: 'ModuleHello', ModuleHello }],
  },
]);

Load configuration injection

madig.load method will instanciate all classes declared in the configuration object and inject them.

// Load injection
madig.load();

How does it works

The loading function determines the classes order of instantiation to be able to instantiate them with constructor dependencies.

For example, the previous configuration

[
  {
    class: TodoController,
    dependsOn: [TodoService],
  },
  {
    class: TodoService,
    dependsOn: [TodoRepository, { name: 'ModuleHelloBis', ModuleHelloBis }],
  },
  {
    class: TodoRepository,
    dependsOn: [Db, { name: 'ModuleHello', ModuleHello }],
  },
]

Will be injected in the following order :

• ModuleHelloBis
• Db
• ModuleHello
• TodoRepository
• TodoService
• TodoController

Access to the IOC container

The IOC container is not necessary in a classic usage because all dependencies are automaticly injected.

If you still need access to the container, you can do it like this : madig.container.get('ClassName');

Example :

madig.container.get('TodoController'); // returns TodoController instance

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT