typedi 是typestack團隊提供的依賴注入解決方案，對於typescript 我們可以使用注解的開發方式，官方的文檔也比較詳細
javascript 使用
- 基於函數的服務注入
var Service = require("typedi").Service;
var Container = require("typedi").Container;
var PostRepository = Service(() => ({
getName() {
return "hello from post repository";
}
}));
var PostManager = Service(() => ({
getId() {
return "some post id";
}
}));
class PostQueryBuilder {
build() {
return "SUPER * QUERY";
}
}
var PostController = Service([
PostManager,
PostRepository,
PostQueryBuilder
], (manager, repository, queryBuilder) => {
return {
id: manager.getId(),
name: repository.getName(),
query: queryBuilder.build()
};
});
var postController = Container.get(PostController);
console.log(postController);
- 基於名稱的注入
var Container = require("typedi").Container;
class BeanFactory {
constructor(container){}
create() {
console.log("BeanFactory")
}
}
class SugarFactor {
constructor(container){}
create() {
console.log("SugarFactory")
}
}
class WaterFactory{
constructor(container){}
create() {
console.log("WaterFactory")
}
}
class CoffeeMaker {
constructor(container) {
this.beanFactory = container.get("bean.factory");
this.sugarFactory = container.get("sugar.factory");
this.waterFactory = container.get("water.factory");
}
make() {
this.beanFactory.create();
this.sugarFactory.create();
this.waterFactory.create();
}
}
Container.set("bean.factory", new BeanFactory(Container));
Container.set("sugar.factory", new SugarFactory(Container));
Container.set("water.factory", new WaterFactory(Container));
Container.set("coffee.maker", new CoffeeMaker(Container));
var coffeeMaker = Container.get("coffee.maker");
coffeeMaker.make();
typescript 使用
對於typescript 的使用我們可以利用ts提供的強大類型能力,以及注解可以編寫強大的功能
- 簡單service注解
項目結構
ts
└── service
├── SomeClass.ts
└── demo.ts
demo.ts
import {Container} from "typedi";
import {SomeClass } from "./SomeClass"
let someClass = Container.get(SomeClass);
someClass.someMethod();
SomeClass.ts
import "reflect-metadata";
import {Service} from "typedi";
@Service()
class SomeClass {
someMethod() {
console.log("call from service")
}
}
export default SomeClass
export {
SomeClass
}
- 基於屬性的注入
import "reflect-metadata"
import {Container, Inject, Service} from "typedi";
@Service()
class BeanFactory {
create() {
console.log("BeanFactory")
}
}
@Service()
class SugarFactory {
create() {
console.log("SugarFactory")
}
}
@Service()
class WaterFactory {
create() {
console.log("WaterFactory")
}
}
@Service()
class CoffeeMaker {
@Inject()
beanFactory: BeanFactory;
@Inject()
sugarFactory: SugarFactory;
@Inject()
waterFactory: WaterFactory;
make() {
this.beanFactory.create();
this.sugarFactory.create();
this.waterFactory.create();
}
}
let coffeeMaker = Container.get(CoffeeMaker);
coffeeMaker.make();
- 基於服務名的注入
import "reflect-metadata"
import {Container, Service, Inject} from "typedi";
interface Factory {
create(): void;
}
@Service("bean.factory")
class BeanFactory implements Factory {
create() {
console.log("BeanFactory")
}
}
@Service("sugar.factory")
class SugarFactory implements Factory {
create() {
console.log("SugarFactory")
}
}
@Service("water.factory")
class WaterFactory implements Factory {
create() {
console.log("WaterFactory")
}
}
@Service("coffee.maker")
class CoffeeMaker {
beanFactory: Factory;
sugarFactory: Factory;
@Inject("water.factory")
waterFactory: Factory;
constructor(@Inject("bean.factory") beanFactory: BeanFactory,
@Inject("sugar.factory") sugarFactory: SugarFactory) {
this.beanFactory = beanFactory;
this.sugarFactory = sugarFactory;
}
make() {
this.beanFactory.create();
this.sugarFactory.create();
this.waterFactory.create();
}
}
let coffeeMaker = Container.get<CoffeeMaker>("coffee.maker");
coffeeMaker.make();
- 循環依賴的處理
對於循環依賴我們需要指定類型，如下：
// Car.ts
@Service()
export class Car {
@Inject()
engine: Engine;
}
// Engine.ts
@Service()
export class Engine {
@Inject()
car: Car;
}
應該為:
// Car.ts
@Service()
export class Car {
@Inject(type => Engine)
engine: Engine;
}
// Engine.ts
@Service()
export class Engine {
@Inject(type => Car)
car: Car;
}
- 注入繼承
// Car.ts
@Service()
export abstract class Car {
@Inject()
engine: Engine;
}
// Engine.ts
@Service()
export class Bus extends Car {
// you can call this.engine in this class
}
- 服務組
方便組合依賴的服務
// Factory.ts
import "reflect-metadata"
import {Container, Service,Token} from "typedi";
export interface Factory {
create(): any;
}
// FactoryToken.ts
export const FactoryToken = new Token<Factory>("factories");
// BeanFactory.ts
@Service({ id: FactoryToken, multiple: true })
export class BeanFactory implements Factory {
create() {
console.log("bean created");
}
}
// SugarFactory.ts
@Service({ id: FactoryToken, multiple: true })
export class SugarFactory implements Factory {
create() {
console.log("sugar created");
}
}
// WaterFactory.ts
@Service({ id: FactoryToken, multiple: true })
export class WaterFactory implements Factory {
create() {
console.log("water created");
}
}
// app.ts
// now you can get all factories in a single array
Container.import([
BeanFactory,
SugarFactory,
WaterFactory,
]);
const factories = Container.getMany(FactoryToken); // factories is Factory[]
factories.forEach(factory => factory.create());
說明
typedi 功能還是很強大，是web開發中的一個利器
參考資料
https://github.com/typestack/typedi
https://github.com/rongfengliang/typedi-learning