Flow-Master

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  flow: Ember.inject.service(),
  
  routes: Ember.computed.readOnly('flow.routes'),
  
  
});

models.flow.js

import Model from 'ember-data/model';
import attr from "ember-data/attr";

export default Model.extend({
  title: attr('string'),
  routes: attr()
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  setupController() {
    let data = {title: 'myRoute', routes: [1,2,3,4,5]};
  }
});
  

services.flow.js

// import Ember from 'ember';
import Service from 'ember-service';
import computed from 'ember-macro-helpers/computed';
import set from 'ember-metal/set';
import get from 'ember-metal/get';
import { readOnly } from 'ember-computed';

export default Service.extend({

  // the flow model
  flow: null,

  // number of times the
  // service has been flushed
  flushCount: 0,

  routes: readOnly('flow.routes'),

  isFirst: computed('_currentIndex', 'routes', 'flushCount', {
    get(index) {
      return index === 0;
    }
  }),

  isLast: computed('_currentIndex', 'routes', 'flushCount', {
    get(index, collection) {
      let lastItem = get(collection, 'length') - 1;
      return index === lastItem;
    }
  }),

  currentRoute: computed('_currentIndex', 'routes', 'flushCount', {
    get(index, collection) {
      return collection[index];
    }
  }),

  nextRoute: computed('_currentIndex', 'routes', 'isLast', 'flushCount', {
    get(index, collection, isLast) {
      if (!isLast) {
        return collection[index + 1];
      } else {
        return null;
      }
    }
  }),

  _currentIndex: computed(),

  reset(flow) {
    let isSet = set(this, 'flow', flow);

    if (isSet) {
      this.incrementProperty('flushCount');
      set(this, '_currentIndex', 0);
    }
  },

  next() {
    let _currentIndex = get(this, '_currentIndex');
    _currentIndex.incrementProperty();
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>
<p>number of routes :: </p>

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"
  }
}