New Twiddle

components.my-slider-item.js

import Ember from 'ember';
import { A } from '@ember/array';


export default Ember.Component.extend({
    
  init() {
  	this._super(...arguments);
  	//this.get('registerItem')(this);
  }
});

components.my-slider.js

import Ember from 'ember';
import { A } from '@ember/array';
import { computed } from '@ember/object';



export default Ember.Component.extend({
    
  itemsPerSlide: 2,
  
  currentScreen: 0,
  
  
  init() {
    this._super(...arguments);
    this.set('items', A());
    this.set('slides', Array.from({ length: 2 }, (v, i) => i));
  },
  
  actions: {
  
    next() {
    	this.incrementProperty('currentSlide');
    },
    
    prev() {
    	this.decrementProperty('currentSlide');
    },
    
    registerItem(item) {
    	this.get('items').pushObject('item');
    }
  
		
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
1

{{#my-slider itemPerSlide=2 as |s|}}
	{{#s.item}}
  		bah1
  {{/s.item}}
  {{#s.item}}
  		bah2
  {{/s.item}}
  {{#s.item}}
  		bah3
  {{/s.item}}
  {{#s.item}}
  		bah4
  {{/s.item}}
{{/my-slider}}
<br>
<br>

templates.components.my-slider-item.hbs

{{yield}}

templates.components.my-slider.hbs

currentScreen: {{currentSlide}}
<nav>
	<button {{action "prev"}}>&lt;</button>
	<button {{action "next"}}>&gt;</button>
</nav>

<section>
		{{#each slides as |slide index|}}
      <div class={{concat 'slide-' index }}>
        {{yield (hash item=(component 'my-slider-item' ))}}
      </div>
		{{/each}}	

</section>

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}