Introduction: di-type

This npm module support the ability of dependency injection and thereby also dependency inversion. It can be used to provide singletons to any class that might need a singleton of another class. The module is designed to be used as an decorator. This means experimentalDecorators: true should be set in your projects tsconfig.json.

Usage

To use this in your project and save it in the package.json file do: npm install di-type --save

Please be aware that we use semantic versioning. This means that you should be able to safely subscribe to updates on this module for versions 1.x.x or 2.x.x etc. Major versions for example from 1.x.x to 2.x.x is not safe as the module API might change.

Getting dependencies

In order to include a dependency it is important to understand WHEN it is needed. For applications there might be a runtime configuration phase. This is where a class might need acces to some providers. When this phase has ended there might be a need to acces the configured providers or directives as they are called here.

Example

An example is given here. Please be aware that the class SetConfig will run before SomeConsumer even tho it is denoted after the other class.

// import the Component and bootstrap from our libery make sure that it is installed first
import {Component, bootstrap}  from 'di-type';

// another class that is needed a singleton of
import {SomeConfigService} from './somepath';
import {SomeService}       from './someotherpath';

@Component({
    directives: [SomeConfigService],
    providers: []
})
class SomeConsumer {
    constructor(scs: SomeConfigService) {

        // here we can use the configured config service
    }
}

@Component({
    directives: [SomeService],
    providers: [SomeConfigService]
})
class SetConfig {
    constructor(scs: SomeConfigService, ss: SomeService) {

        // here we can change the content of scs using the ss
    }
}

class Application {
    constructor () {

        // doing something cool here
    }
}

// start up everthing
bootstrap(Application);

The bootstrap function takes one parameter. This parameter is the MAIN class of your application.

License

The MIT License (MIT)