具名绑定

原文链接

TIP

具名绑定和带标签绑定类似

我们可以通过具名绑定来修复AMBIGUOUS_MATCH错误。该错误的产生原因是：两个以上的具体类被绑定到一个抽象。注意Ninja类的构造函数参数是如何使用@named装饰器修饰的：

interface Weapon {}

@injectable()
class Katana implements Weapon {}

@injectable()
class Shuriken implements Weapon {}

interface Ninja {
    katana: Weapon;
    shuriken: Weapon;
}

@injectable()
class Ninja implements Ninja {
    public katana: Weapon;
    public shuriken: Weapon;
    public constructor(
        @inject("Weapon") @named("strong") katana: Weapon,
        @inject("Weapon") @named("weak") shuriken: Weapon
    ) {
        this.katana = katana;
        this.shuriken = shuriken;
    }
}

我们将Katana和Shuriken绑定到了Weapon，同时添加了whenTargetNamed约束条件来避免产生AMBIGUOUS_MATCH错误:

container.bind<Ninja>("Ninja").to(Ninja);
container.bind<Weapon>("Weapon").to(Katana).whenTargetNamed("strong");
container.bind<Weapon>("Weapon").to(Shuriken).whenTargetNamed("weak");