Theme Service

components.x-button.js

import Ember from 'ember';
import ThemeMixin from 'app/mixins/theme';

export default Ember.Component.extend(ThemeMixin, {
  tagName: 'button',
  label: '',
  themeType: 'button'
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  themeService: Ember.inject.service('theme'),
  
  buttonSubmitTheme: Ember.computed('themeService.themes.[]', function() {
    return this.get('themeService').lookupTheme('button', 'submit');
  }),
  
    
  buttonCancelTheme: Ember.computed('themeService.themes.[]', function() {
    return this.get('themeService').lookupTheme('button', 'cancel');
  }),
  
});

mixins.theme.js

import Ember from 'ember';

export default Ember.Mixin.create({
  attributeBindings: 'style',

  themeService: Ember.inject.service('theme'),
  
  themeType: '',
  themeSubtype: '',
  
  theme: Ember.computed('themeService.themes.[]', 'themeType', 'themeSubtype', function() {
    let type = this.get('themeType');
    let subtype = this.get('themeSubtype');
    return this.get('themeService').lookupTheme(type, subtype);
  }),
  
  style: Ember.computed('theme.style', function() {
    let style = this.get('theme.style') || '';
    return Ember.String.htmlSafe(style);
  })
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  themeService: Ember.inject.service('theme'),
  
  afterModel() {
    return this.get('themeService').fetchThemes();
  }
});

services.theme.js

import Ember from 'ember';

export let ThemeModel = Ember.Object.extend({
  type: '',
  subtype: '',
  
  backgroundColor: '#FFF',
  fontSize: '13px',
  
  style: Ember.computed('backgroundColor', 'fontSize', function() {
    let bgColor = this.get('backgroundColor');
    let fontSize = this.get('fontSize');
    
    return Ember.String.htmlSafe(`font-size: ${fontSize}; background-color: ${bgColor};`);
  })
});

export default Ember.Service.extend({
  init() {
    this._super(...arguments);
    this.set('themes', []);
  },
  
  themes: null,
  
  fetchThemes() {
    // NORMALLY AJAX
    let themes = [
      ThemeModel.create({ type: 'button', subtype: 'submit', backgroundColor: '#6FB400' }),
      ThemeModel.create({ type: 'button', subtype: 'cancel', backgroundColor: '#98AAB3' })
    ];
    this.set('themes', themes);
  },
  
  lookupTheme(type, subtype) {
    return this.get('themes').find(theme => {
      return theme.get('type') === type && theme.get('subtype') === subtype;
    });
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
Submit Theme
{{input value=buttonSubmitTheme.backgroundColor}}
{{input value=buttonSubmitTheme.fontSize}}
<br>
Cancel Theme
{{input value=buttonCancelTheme.backgroundColor}}
{{input value=buttonCancelTheme.fontSize}}
<hr>
{{outlet}}
<br>
{{x-button label="Submit" themeSubtype="submit"}}
{{x-button label="Cancel" themeSubtype="cancel"}}

templates.components.x-button.hbs

{{label}}

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}