discourse-custom-wizard/assets/javascripts/discourse/components/wizard-mapper-pair.js.es6

import { connectorContent } from '../lib/custom-wizard';
import { gt, or, alias } from "@ember/object/computed";
import { computed, observes } from "@ember/object"; 

export default Ember.Component.extend({
  classNameBindings: [':mapper-pair', 'hasConnector::no-connector'],
  firstPair: gt('pair.index', 0),
  showRemove: alias('firstPair'),
  showJoin: computed('pair.pairCount', function() {
    return this.pair.index < (this.pair.pairCount - 1);
  }),
  connectors: computed(function() { 
    return connectorContent('pair', this.inputType, this.options);
  })
});