Assisted injection in Aurelia?

Question

I have a class whose constructor has two arguments; one is a dependency, the other is a configuration property:

@injec         


        

Answer 1

In the end I created a custom resolver, which means the code is nice and modular and easy to use in other classes.

foo.js

import {inject} from 'aurelia-framework';
import {FooDependency} from './foo-dependency';

@inject(Dependency)
export class Foo{
  constructor(dep, cfg){}

  static useArgs(...args){
     return new Resolver(Foo, args);
  }
}

@resolver
class Resolver{
  constructor(Class, args){
    this.Class = Class;
    this.args = args;
  }

  get(container){
    var Class = this.Class,
      // Class.inject is the array of the class's dependencies
      // we need to resolve them all before they're useful
      dependencies = Class.inject.map((dep)=>container.get(dep)),
      // Pass the resolved dependencies + any additional arguments to the new class
      args = dependencies.concat(this.args);

    return new Class(...args);
  }
}

needs-foo.js

import {inject} from 'aurelia-framework';
import {Foo} from 'foo';

@inject(Foo.useArgs('my config'))
export class NeedsFoo{
    constructor(fooConfigured){
    }
}