如何在Aurelia的父类中注入？

Question

我有一个父类,我想要注入一些模块,然后我有一些派生类,我想使用这些注入的模块.但是在派生类中,您必须在super()没有参数的情况下调用,因此未在父类中注入模块.怎么可以这样做？

import {inject} from 'aurelia-framework';
import {HttpClient} from 'aurelia-http-client';

@inject (HttpClient)
export class Parent{
   constructor(module){
       //this constructor is called from derived class without parameters,
       //so 'module' is undefined !!
       this.injectedmodule = module;
   }
}


export class ClassA extends Parent{
    constructor(){
       super();
       this.injectedmodule.get()  // injectedmodule is null !!!   
    }
}

Answer 1

好吧,刚刚找到解决方案,模块实际上是在派生类中注入并通过super()调用传递给父类:

import {inject} from 'aurelia-framework';
import {HttpClient} from 'aurelia-http-client';

@inject (HttpClient)
export class Parent{
    constructor(module){
       this.injectedmodule = module;
    }
}


export class ClassA extends Parent{
    constructor(module){
       super(module);
       this.injectedmodule.get()  // ok !!!   
    }
}

Answer 2

一般建议是尽可能避免继承.而是利用构图.在这种情况下:

import {inject} from 'aurelia-framework';
import {HttpClient} from 'aurelia-http-client';

@inject (HttpClient)
export class Parent{
    constructor(module){
       this.injectedmodule = module;
    }
}

@inject(Parent)
export class ClassA {
    constructor(parent){
       this.parent = parent;
       this.parent.injectedmodule.get()  // ok !!!   
    }
}