带标签的绑定

我们可以通过为绑定设置标签来修复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@tagged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") @tagged("canThrow", false) katana: Weapon,
        @inject("Weapon") @tagged("canThrow", true) shuriken: Weapon
    ) {
        this.katana = katana;
        this.shuriken = shuriken;
    }
}

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我们将Katana和Shuriken绑定到了Weapon，同时添加了whenTargetTagged约束条件来避免出现AMBIGUOUS_MATCH错误:

container.bind<Ninja>(ninjaId).to(Ninja);
container.bind<Weapon>(weaponId).to(Katana).whenTargetTagged("canThrow", false);
container.bind<Weapon>(weaponId).to(Shuriken).whenTargetTagged("canThrow", true);

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# 带标签的绑定

带标签的绑定