Approach2 - DataService

components.alerts\.js

import Component from '@glimmer/component';
import { action, get } from '@ember/object';
import { tracked } from '@glimmer/tracking';
import { inject as service } from '@ember/service';
import { getOwner } from '@ember/application';

export default class Filters extends Component {
  // get dataService() {
  //   const fullName = 'service:' + get(this.args, 'dataServiceName');
  //   return getOwner(this).lookup(fullName);
  // }
  
  get filterValue() {
    const dataService = get(this.args, 'dataService');
    return get(dataService, 'filterValue');
  }
}

components.filters\.js

import Component from '@glimmer/component';
import { action, get } from '@ember/object';
import { getOwner } from '@ember/application';

export default class Filters extends Component {
  // get dataService() {
  //   const fullName = 'service:' + get(this.args, 'dataServiceName');
  //   return getOwner(this).lookup(fullName);
  // }
  
  constructor() {
    super(...arguments);
    get(this.args, 'dataService').updateFilterValue(1);
  }
  
  @action
  increaseFilter() {
    const filterValue = get(this.args, 'dataService').filterValue;
    get(this.args, 'dataService').updateFilterValue(filterValue + 1);
  }
}

controllers.application\.js

import Controller from '@ember/controller';

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
}

controllers.index\.js

import Controller from '@ember/controller';

import { inject as service } from '@ember/service';

export default class IndexController extends Controller {
  @service('index-data-service')
  indexDataService;
};

controllers.jymbii\.js

import Controller from '@ember/controller';

export default class IndexController extends Controller {
};

router\.js

import EmberRouter from '@ember/routing/router';
import config from './config/environment';

const Router = EmberRouter.extend({
  location: 'none',
  rootURL: config.rootURL
});

Router.map(function() {
  this.route('jymbii');
});

export default Router;

services.index-data-service\.js

import Service from '@ember/service';
import { tracked } from '@glimmer/tracking';

export default class IndexDataService extends Service{
  // ONLY contains data that is shared across components
  @tracked filterValue = null;

	@action
	updateFilters(filterValue) {
    this.filterValue = filterValue;
  }
// getter, setter, data fetchers, data formatters; state
};

services.jymbii-data-service\.js

import Service from '@ember/service';
import { tracked } from '@glimmer/tracking';

export default class JymbiiDataService extends Service{
  @tracked filterValue = null;
  
  initializeFilters(filterValue) {
    this.filterValue = filterValue;
  }

  increaseFilter() {
    this.filterValue++;
  }
};

templates.application\.hbs

<div style="outline: 1px solid black;">
  <h1>Approach 2 - QC as Data Service</h1>
  {{outlet}}
</div>

templates.components.alerts\.hbs

<div style="outline: 1px solid black; width: 80%; margin: 20px; padding: 10px;">
    <h3>
        Alerts component
    </h3>

    <div>
      Data passed down into the component reflects here
    </div>
    
    {{!--
    <code>
      <div> get dataService() { </div>
      <div> &nbsp; &nbsp; getOwner(this).lookup(this.args.dataServiceName); </div>
      <div> } </div>

      <div> filterValue() { </div>
      <div> &nbsp; &nbsp; get(this, 'dataService').filterValue; </div>
      <div> } </div>
    </code>
    --}}
  
    <div style="color:red;">
      Current Filter Value = {{this.filterValue}}
    </div>
</div>

templates.components.filters\.hbs

<div style="outline: 1px solid black; width: 80%; margin: 20px; padding: 10px">
    <h3>
        Filters component
    </h3>

    <div>
      Actions triggered here are invoked from the dataService
    </div>
    
    {{!-- 
    <code>
      <div> get dataService() { </div>
      <div> &nbsp; &nbsp; getOwner(this).lookup(this.args.dataServiceName); </div>
      <div> } </div>

      <div> constructor() { </div>
      <div> &nbsp; &nbsp; get(this, 'dataService').initializeFilters(1); </div>
      <div> } </div>

      <div> increaseFilter() { </div>
      <div> &nbsp; &nbsp; get(this, 'dataService').increaseFilter(); </div>
      <div> } </div>
    </code>
    --}}

    <div>
      <button onclick={{action "increaseFilter"}}> Click to increase filter value </button>
    </div>
</div>

templates.index\.hbs

<div style="outline: 1px solid black; width: 80%; margin: 20px;padding: 10px;">
  <h2>
    Index route loaded
  </h2>
  
  <div>
  	<p> Route defines the dataService </p>
    <p> index-data-service handles the state and actions</p>
  	<p> index-data-service implements filterValue, increaseFilter etc </p>
  </div>

	<h4> Index Template </h4>
  <div> Filters </div>
  <div> &nbsp; &nbsp; @dataService=this.indexDataService </div>

  <Filters
    @dataService={{this.indexDataService}}
 	/>
  
  <div> Alerts </div>
  <div> &nbsp; &nbsp; @dataService=this.indexDataService </div>
  <Alerts
    @dataService={{this.indexDataService}}
  />
</div>

templates.jymbii\.hbs

<div style="outline: 1px solid black; width: 80%; margin: 20px;padding: 10px;">
  <h2>
    Jymbii route loaded
  </h2>
  
  <div>
  	<p> Route defines the dataService </p>
    <p> jymbii-data-service handles the state and actions</p>
  	<p> jymbii-data-service implements filterValue, increaseFilter etc </p>
  </div>

	<h4> Jymbii Template </h4>
  <div> Filters </div>
  <div> &nbsp; &nbsp; @dataServiceName='jymbii-data-service' </div>

  <Filters
    @dataServiceName='jymbii-data-service'
  />
  
  <div> Alerts </div>
  <div> &nbsp; &nbsp; @dataServiceName='jymbii-data-service' </div>
  <Alerts
    @dataServiceName='jymbii-data-service'
  />
</div>

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"
  }
}