get() with dots

controllers.application.js

import Ember from 'ember';

const { get } = Ember;

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  transition: Ember.Object.create({ 
    params: { 
      'dynamicForm.show': { vendor_id: 'WINNER' } 
    } 
  }),
  vendorId: Ember.computed(function() {
  	let transition = get(this, 'transition');
    // MAGIC GOES HERE
    
    // this works but is awkward...
    //let vendorId = transition.params && transition.params['dynamicForm.show'] && transition.params['dynamicForm.show'].vendor_id;
    
    // would like to do something like this, but noooo
    //let vendorId = get(transition, 'params["dynamicForm.show"].vendor_id');
    
    let vendorId;
    
    // END MAGIC
    return vendorId;
  })
});

templates.application.hbs

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

vendorId = "{{vendorId}}"

twiddle.json

{
  "version": "0.10.6",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.9.0",
    "ember-data": "2.9.0",
    "ember-template-compiler": "2.9.0",
    "ember-testing": "2.9.0"
  },
  "addons": {}
}