QP Service

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  paramsService: Ember.inject.service('params'),
  appName: 'Ember Twiddle',
  queryParams: ['theme', { isSidebar: 'sidebar' }],
  theme: 'bye',
  isSidebar: false,
  counter: 0,
  
  init() {
     this._super(...arguments);
    var paramsService = this.get('paramsService');
    
    //paramsService.subscribe('theme', (key, theme) => this.set('theme', theme));
    paramsService.subscribeAll(this);
    paramsService.subscribe('theme', (key, theme) => this.set('theme2', theme+2));
  },
  
  actions: {
  	updateTheme() {
    	var paramsService = this.get('paramsService');
      var counter = this.incrementProperty('counter');
      
      paramsService.setParam('theme', `hi${counter}`);
      paramsService.setParam('isSidebar', counter % 2 === 1);
    }
  }
});

services.params.js

import Ember from 'ember';

const map = new Map();

export default Ember.Service.extend({
  setParam(name, value) {
    if (map.has(name)) {
      map.get(name).value = value;
      this.callCbs(name);
    } else {
      map.set(name, {
        value,
        cbs: []
      });
    }
  },
  
  getParam(name) {
  	var item = map.get(name);
    return item ? item.value : undefined;
  },

  subscribe(name, cb) {
    if (map.has(name)) {
      let item = map.get(name);
      item.cbs.push(cb);
    } else {
    	map.set(name, {
				value: undefined,
        cbs: [cb]
      });
    }
  },
  
  subscribeAll(context) {
  	if (!context || !context.queryParams) {
    	return;
    }
    
    let keys = context.queryParams.reduce((all, item) => {
    	if (typeof item === 'string') {
      	all.push(item);
      } else if (typeof item === 'object') {
      	all = all.concat(Object.keys(item));
      }
      
      return all;
    }, []);
    
    let update = (name, val) => { Ember.run(context, 'set', name, val); }
    keys.forEach(key => this.subscribe(key, update));
  },
 
  callCbs(name) {
  	if (map.has(name)) {
      let item = map.get(name);
      item.cbs.forEach(cb => cb(name, item.value));
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>
<button type="button" {{action 'updateTheme'}}>Test</button><br>
{{theme}}<br/>
{{theme2}}<br/>
{{isSidebar}}

twiddle.json

{
  "version": "0.7.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.4.4",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.3/ember-data.js",
    "ember-template-compiler": "2.4.4"
  }
}