robinbuschmann/ts-di

TypeScript version of Angular Dependency Injection Framework

⚠️ THIS PACKAGE IS DEPRECATED

Please use https://github.com/mgechev/injection-js instead

---

Dependency Injection

di-typescript is a simple dependency injection framework, which is build upon ts-di and angular/di.js.

Install

npm install di-typescript --save

Configuration

tsconfig.json file needs the following flags:

"experimentalDecorators": true,
"emitDecoratorMetadata": true

Usage

Using @Inject and create an instance

The following shows how to inject an instance of UserService into the constructor of App.

import {Inject, Injector} from 'di-typescript';

class UserService{}

@Inject
class App
{
  constructor(protected userService: UserService){}

}

const injector = new Injector();
// resolves UserService by creating an instance or retrieves it, when already exists
const app = injector.get(App); 

Using factories and tokens

If a dependency should not been resolved from a class but a function or a simple value, @useFactory or @useToken can be used like:

import {Inject, createToken, useToken, useFactory} from 'di-typescript';

interface IStorage { /* ... */ }
const storage: IStorage = { /* ... */ };
const storageFactory = () => storage;

interface IConfig { /* ... */ }
const configToken = createToken('app.config');

@Inject
class App
{
  constructor(protected userService: UserService,
              @useToken(configToken) protected config: IConfig,
              @useFactory(storageFactory) protected storage: IStorage){}

}

const config: IConfig = { /* ... */ };
const injector = new Injector([{provide: configToken, useValue: config}]);
const app = injector.get(App);

Testing and providing different values for specific tokens

When it comes to testing and further a mock should be injected than the actual service, this can be achieved as the following.

class UserService{}
class UserServiceMock{}

function storageMockFactory() {
  /* ... */
}

@Inject
class App
{
  constructor(protected userService: UserService,
              @useFactory(storageFactory) protected storage: IStorage){}

}

const injector = new Injector([
  {provide: UserService, useClass: UserServiceMock},
  {provide: storageFactory, useFactory: storageMockFactory},
]);
const app = injector.get(App);

Differences between di-typescript and angular/di.js

Compared to ts-di and angular/di.js di-typescript uses reflect-metadata to store the meta information. A benefit from using reflect-metadata is, that theInject decorator don't need parameters anymore. di-typescript retrieves these values through the design:paramtypes meta information provided by typescript instead. Another features are the useFactory annotation and the angular2-like {provide: SomeService, useClass/useValue/useFactory} syntax when creating an injector.

ts-di's Issues

Implement ValueProvider, FactoryProvider like it is done in angular 2

Add possibility to inject a value or a factory(function). See this for further information.

Not working

Hello!

I've installed the module and tried to use example from the README, but it's not working.

userService is not injected to the App constructor.

Is this module works? Are you using it in production?

error TS7006: Parameter '_meta' implicitly has an 'any' type.

Hello!

Thank you for this great library!

However, when I try to compile it with a simple app, I'm getting the following error:

$ tsc

220         const foundMeta = meta.find(_meta => _meta.index === index);
                                        ~~~~~

node_modules/di-typescript/lib/annotations.ts(220,37): error TS7006: Parameter '_meta' implicitly has an 'any' type.

$ tsc --version
Version 2.2.1

tsconfig.json

{
  "compilerOptions": {
    "module": "commonjs",
    "target": "ES6",
    "alwaysStrict": true,
    "listEmittedFiles": true,
    "noImplicitAny": true,
    "outDir": "dist/",
    "pretty": true,
    "removeComments": true,
    "sourceMap": true,
    "typeRoots": [
      "node_modules/@types"
    ]
  },
  "include": [
    "src/**/*"
  ],
  "exclude": [
    "node_modules/"
  ]
}

What could be the problem?

Thanks!