Relationship Cache

controllers.application.js

import Ember from 'ember';

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

models.city.js

import LibraryOwner from "./libraryowner";
import { belongsTo } from "ember-data/relationships";

export default LibraryOwner.extend({
  main: belongsTo('library'),
  science: belongsTo('library')
});

models.library.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo } from "ember-data/relationships";

export default Model.extend({
  owner: belongsTo('libraryowner', { polymorphic: true }),
  ownerType: attr('string'),
  ownerId: attr('string'),
  name: attr('string')
});

models.libraryowner.js

import Model from "ember-data/model";

export default Model.extend({
});

routes.application.js

import Ember from 'ember';

const { RSVP: { hash } } = Ember;

const library1Data = {
  data: {
    id: 1,
    type: 'library', 
    attributes: {
    	name: 'Main branch'
    },
    relationships: {
      data: { id: 1, type: 'city' }
    }
  }
};

const library2Data = {
  data: {
    id: 2,
    type: 'library', 
    attributes: {
    	name: 'Science branch'
    },
    relationships: {
      data: { id: 1, type: 'city' }
    }
  }
};

const cityData = {
  data: {
    id: 1,
    type: 'city',
    attributes: {},
    relationships: {
      main: { 
        data: { id: 1, type: 'library' }
      },
      science: {
        data: { id: 2, type: 'library' }
      }
    }
  }
};

export default Ember.Route.extend({
  model() {
    this.store.push(library1Data);
    this.store.push(library2Data);
    this.store.push(cityData);
		this.store.unloadAll('library');
    this.store.unloadAll('city');
    
    this.store.push(library1Data);
    this.store.push(library2Data);
    let city = this.store.push(cityData);
    return hash({
      city,
      main: city.get('main'),
      science: city.get('science')
    });
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
Main library name: {{model.main.name}}
<br>
Science library name: {{model.science.name}}
<br>
<br>

twiddle.json

{
  "version": "0.13.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.16.2",
    "ember-template-compiler": "2.16.2",
    "ember-testing": "2.16.2"
  },
  "addons": {
    "ember-data": "2.18.2"
  }
}