uditalias / injex Goto Github PK

Hi @uditalias,
First of all, great work, I really like the idea of auto-scanning all the classes/modules annotated with @define.

I've created this small demo https://github.com/flowck/injex-demo where I attempt to implement injex/node, but I can't make it work, and the run() method from the bootstrap class doesn't quite run. I probably made a basic mistake somewhere but I can't quite figure it out.

When I try to run the application after being compiled, I get this error:

Sorry for this issue.

Kind regards,
Firmino.

There should be an option to inject the container into itself, so a module can require it using the @inject() decorator.

For example:

@define()
export class MyModule {
    // injecting the runtime container
    @inject() private $injex: Injex;

    public addItem(item, name) {
        // using the runtime container API
        this.$injex.addObject(item, name);
    }
}

Today, when creating a runtime container, its reference is not accessible from the ecosystem of Injex.

Is your feature request related to a problem? Please describe.

Wondering if it were possible in this library to do parameter dependency injection into the constructor instead of property dependency injection. Various articles seem to be against the latter though I am learning DI at the moment so I have no idea what the correct answer is.

Describe the solution you'd like

I have not tested this, but I ended up writing a small wrapper to implement this.

// src/lib/runtime/injex.ts
export const injectParam = (shadowedKey: string, dependencyNameOrType?: any) => {
  return function (target: any, _key: string | symbol, _index: number) {
    // _key is `undefined` in the constructor, I think, and _index doesn't
    // seem to be useful in guessing the value of `shadowedKey`
    inject(dependencyNameOrType)(target.prototype, shadowedKey);
  };
}

// Usage
import { Dependency } from "somewhere/in/my/project"

export class SomeService {
  constructor(
    // Here `dep` is required as I couldn't find a way to 
    // get the name of the paramter in the constructor using 
    // `reflect-metadata`
    @injectParam("dep", Dependency) private dep: Dependency) {}
  
  public someMethod() {
    const someResult = this.dep.someResource();
    // ...
  }
}

It's not great as two function parameters in the decorator go unused, but I'm sure someone more qualified can come up with a solution to that - maybe even detect the parameter names in the constructor.

Describe alternatives you've considered
InversifyJS includes the desired functionality with the caveat that it requires explicit registration of dependencies which I am too lazy to consider (I am only building a small app at the moment, no need for overkill, methinks).

Additional context
What prompted this feature request: