在没有构造函数的情况下将服务单例实例注入到另一个服务

Question

I have:

• BaseService that would be used as parent class
• UtilService is used for utility functions
• AService is child class of BaseService (AService extends from BaseService)
• BService is also child class of BaseService

I want to inject UtilService singleton instance to BaseService but without using constructor ( constructor(baseService: BaseService){} ) because if not, both AService and BService need to pass UtilService singleton instance as argument when calling UtilService 's constructor ( super(arguments) ) which is obviously a redundant step. So I want to know if there is any another way to do this without passing UtilService singleton instance in AService/BService constructor's super call. Thanks in advance.

Answer 1

I don't know if it will be singelton, but you can inject a service using

constructor(private inj: Injector) { }
....where you need..
const customService= this.inj.get(CustomService)