image.js

import DS from 'ember-data';
import Ember from 'ember';

var attr      = DS.attr;
var belongsTo = DS.belongsTo;

export default DS.Model.extend({
  url:       attr(),
  image:     attr(),
  caption:   attr(),
  sortKey:   attr('number', { defaultValue: 99 }),
  event:     belongsTo('event'),

  backgroundImageStyle: Ember.computed('url', 'image', function() {
    var image = this.get('url');
    if(!image) {
      image = this.get('image');
    }
    return 'background-image:url(' + image + ');';
  })
});