InversifyJS轻量级反转控件容器
InversifyJS 一个强大而轻量级的反转控件 (IoC) 容器，适用于由TypeScript编写的JavaScript和Node.js应用。它使用类构造函数去定义和注入它的依赖。InversifyJS API友好易懂，鼓励对OOP和IoC最佳实践的应用。
InversifyJS有4个主要目标:
-
允许JavaScript开发人员编写遵循 SOLID 原则的代码。
-
促进并鼓励遵守最佳的面向对象编程和依赖注入实践。
-
尽可能少的运行时开销。
-
提供艺术编程体验和生态。
使用
步骤 1：定义接口
// file interfaces.ts
export interface Warrior {
fight(): string;
sneak(): string;
}
export interface Weapon {
hit(): string;
}
export interface ThrowableWeapon {
throw(): string;
}
步骤 2：定义依赖
// file entities.ts
import { injectable, inject } from "inversify";
import "reflect-metadata";
import { Weapon, ThrowableWeapon, Warrior } from "./interfaces";
import { TYPES } from "./types";
@injectable()
class Katana implements Weapon {
public hit() {
return "cut!";
}
}
@injectable()
class Shuriken implements ThrowableWeapon {
public throw() {
return "hit!";
}
}
@injectable()
class Ninja implements Warrior {
private _katana: Weapon;
private _shuriken: ThrowableWeapon;
public constructor(
@inject(TYPES.Weapon) katana: Weapon,
@inject(TYPES.ThrowableWeapon) shuriken: ThrowableWeapon
) {
this._katana = katana;
this._shuriken = shuriken;
}
public fight() { return this._katana.hit(); }
public sneak() { return this._shuriken.throw(); }
}
export { Ninja, Katana, Shuriken };
步骤 3：创建并配置 IOC 容器
// file inversify.config.ts
import { Container } from "inversify";
import { TYPES } from "./types";
import { Warrior, Weapon, ThrowableWeapon } from "./interfaces";
import { Ninja, Katana, Shuriken } from "./entities";
const myContainer = new Container();
myContainer.bind<Warrior>(TYPES.Warrior).to(Ninja);
myContainer.bind<Weapon>(TYPES.Weapon).to(Katana);
myContainer.bind<ThrowableWeapon>(TYPES.ThrowableWeapon).to(Shuriken);
export { myContainer };
步骤4：依赖解析
import { myContainer } from "./inversify.config";
import { TYPES } from "./types";
import { Warrior } from "./interfaces";
const ninja = myContainer.get<Warrior>(TYPES.Warrior);
expect(ninja.fight()).eql("cut!"); // true
expect(ninja.sneak()).eql("hit!"); // true
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