如何实现TypeScript decorator？

飞羽2020-06-02

有人可以提供一个简单的示例，演示实现 decorator的正确方法并描述可能的有效 decorator签名中的参数的含义吗？

declare type ClassDecorator = <TFunction extends Function>(target: TFunction) => TFunction | void;
declare type PropertyDecorator = (target: Object, propertyKey: string | symbol) => void;
declare type MethodDecorator = <T>(target: Object, propertyKey: string | symbol, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T> | void;
declare type ParameterDecorator = (target: Function, propertyKey: string | symbol, parameterIndex: number) => void;

此外，在实现 decorator时是否应牢记最佳实践考虑因素？

// This is a factory, returns one of ClassDecorator, // PropertyDecorator, MethodDecorator, ParameterDecorator function Entity(discriminator: string): { return function(target) { // this is the decorator, in this case ClassDecorator. } } @Entity("cust") export class MyCustomer { ... }

如何实现TypeScript decorator？

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