nDI

nDI is a simple Dependency Injection framework.

Installation

npm install ndi

Example

var nDI = require('ndi');
var container = new nDI.Container();

container.setParameter('greeting.name', 'John');
container.set(
  'service.geeter',
  new nDI.FactoryWrapper(
    container,
    function(name) {
      return function() {
        return 'Hello ' + name + '!';
      };
    },
    ['$greeting.name']
  )
);

console.log(container.get('service.geeter')());

Example with express, see the example folder:

> git clone https://github.com/TeddyTN/nDI.git

> cd nDI
> npm install

> cd example
> npm install
> npm start

Define a parameter

The container.setParameter(name, value) method is used to define a parameter.

Arguments

• name: The name of parameter
• value: The value of the parameter

Define a service

The container.set(id, value) method is used to define a service.

Arguments

• id: The id of the service
• value: The value of the service

Load definitions from config file

You can load parameter and service definitions from a json file with the nDI.Loader class.

Usage

  var loader = new Loader(container, baseDir);

  loader.load(filePath);

Constructor arguments

• container: must be an instance of nDI.Container
• baseDir: is the path for loading files

loader.load arguments

• filePath: is the path of the json config file (file path must relative to baseDir)

Config structure

{
  "parameters": {
    "greeting.name": "John"
  },
  "services": {
    "service.geeter": {"type": "factory", "file": "greeter", "arguments": ["$greeting.name"]}
  }
}

Parameter entries are very simple, there are key value pairs.

Service definition fields

• type: The type of the service
  • class: Mark service as a reference to an constructor
  • factory: Mark service to wrapp an factory function
  • instance: Create a new instance of the given constructor
• file: The path to the service (file path must be relative to baseDir)
• arguments: The list of arguments for the service (will be ignored when type is class)
  • @...: Inject the service (must be the service id)
  • $...: Inject the parameter (must be the parameter name)