Proposal extend existing DI framework to allow more than strings for keys

[mikehaas763]

I think it would be useful today to be able to use more than just strings as keys in Angular.js's injector. I'm already aware that the DI framework written for Angular 2 has this capability.

Now that I've been writing all my app code in ES6 and TS I find myself wanting to use a reference to classes/functions like below.

// Module.js
import EmailDao from './EmailDao.js';
export default angular.module('org.name', [])
    .service(EmailDao, EmailDao); // Using a reference token here

// EmailList.js
import EmailDao from './EmailDao.js';

export default class EmailList {
    static get $inject() {
        return [EmailDao]; // Using a reference token here
    }

    constructor(emailDao) {
        this.emails = [];
        emailDao.getForPerson(123)
            .then(emails => this.emails = emails);
    }
}

In very large apps and very large organizations with a lot of shared modules you will often see hacking in a namespace in the string as a result of the key needing to be a string + there is essentially just one injector per ng1 app. For example .service('org.name.namespace.a', EmailDao). By extending the ng1 DI system to be keys by other tokens, we lose the need to use a string for an injector key and being that it's a reference to specific class/function it's guaranteed to be unique.

Thoughts?

[Narretz]

I think this is a duplicate of #10347

My guess is that it's quite complex to support this in 1.x. But if someone has a PR, we can definitely consider it.