New Twiddle

application.controller.js

import Ember from 'ember';

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

application.template.hbs

{{#my-parent as |disabled enable|}}
  {{my-child is-disabled=disabled.A enable=enable id='A' opposite='B'}}
  {{my-child is-disabled=disabled.B enable=enable id='B' opposite='A'}}
  {{my-child is-disabled=disabled.C enable=enable id='C' opposite='D'}}
  {{my-child is-disabled=disabled.D enable=enable id='D' opposite='C'}}
{{/my-parent}}

my-child.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  actions: {
    enable: function() {
      this.getAttr('enable')(this.getAttr('id'), this.getAttr('opposite'));
    }
  }
});

my-child.template.hbs

{{#if is-disabled}}
  {{id}} is disabled.
{{else}}
  {{id}} is enabled.
{{/if}}
<button {{action 'enable'}}>Enable</button>

my-parent.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  disabled: Ember.computed(function() {
  	return {};
  }),
  enableId(id, opposite) {
    this.set('disabled.'+id, false);
    this.set('disabled.'+opposite, true);
  }
});

my-parent.template.hbs

{{yield disabled (action enableId)}}

twiddle.json

{
  "version": "0.4.16",
  "EmberENV": {
    "FEATURES": {}
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.1.0/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.1.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.1.0/ember-template-compiler.js"
  }
}