Tracking Component Arguments

controllers.application\.js

import Controller from '@ember/controller'; 
import { tracked, TrackedObject } from 'tracked-built-ins';
import { action } from '@ember/object';

class Container {
  @tracked options;

  constructor(options = {}) {
    this.options = options;
  }
}

class Options {
  @tracked foo;
  
  constructor(foo) {
    this.foo = foo;
  }
}

export default class ApplicationController extends Controller {
  // Option 1: Tracked binding, no tracking in object
  @tracked container1 = {
    options: { foo: 'bar' }
  };

  // Option 2: Tracked binding, tracked `options`, no tracking on `options` fields
  @tracked container2 = new Container({ foo: 'bar' });

  // Option 3: Tracked binding, options, and one specific field in `options`
  // Note: `@tracked` appears to make the field non-enumerable...
  // https://github.com/emberjs/ember.js/issues/18220
  @tracked container3 = new Container(new Options('bar'));

  // Option 4: Tracked binding, all recursive objects are tracked
  @tracked container4 = new TrackedObject({
    options: new TrackedObject({
      foo: 'bar'
    })
  });

  /** Action for using `tracked` to update object **/

  @action updateContainer(container, key, { target: { value } }) {
    container.options[key] = value;
  }
}

templates.application\.hbs

<OptionsDisplay style="color: red" @container={{this.container1}} />

<input 
	value={{this.container1.options.foo}} 
  {{on 'input' (fn this.updateContainer this.container1 'foo')}} 
/>

{{this.container1.options.foo}}

<OptionsDisplay style="color: blue" @container={{this.container2}} />

<input 
	value={{this.container2.options.foo}} 
  {{on 'input' (fn this.updateContainer this.container2 'foo')}} 
/>

{{this.container2.options.foo}}

<OptionsDisplay style="color: green" @container={{this.container3}} />

<input 
	value={{this.container3.options.foo}} 
  {{on 'input' (fn this.updateContainer this.container3 'foo')}} 
/>

{{this.container3.options.foo}}

<OptionsDisplay style="color: orange" @container={{this.container4}} />

<input 
	value={{this.container4.options.foo}} 
  {{on 'input' (fn this.updateContainer this.container4 'foo')}} 
/>

{{this.container4.options.foo}}

templates.components.options-display\.hbs

<ul ...attributes>
  {{#each-in @container.options as |key value|}}
    <li>{{key}}: {{value}}</li>
  {{else}}
    <li>There don't appear to be any keys on this object...</li>
  {{/each-in}}
</ul>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0",
    "tracked-built-ins": "1.0.2"
  }
}