Ember.JS - toggleProperty toggling all items in list

I have a toggleProperty in the container to toggle a set of actions on each item. The problem is, when the toggle button on 1 item is clicked, every item is toggled, instead of the one that's clicked.

I would love to know how to toggle only the clicked item, not everything from the list.

I am using the ember-cli to build my application.

My category model:

import DS from 'ember-data';

export default DS.Model.extend({
  pk: DS.attr('string'),
  category: DS.attr('string'),
  products: DS.hasMany('product'),
});

My category route:

import Ember from 'ember';

export default Ember.Route.extend({
  model: function() {
    return this.store.findAll('category');
  },
});

My category controller

expand: function() {
  this.toggleProperty('isExpanded', true);
}

My template:

{{#each model as |i|}}
      <tr>
        <td>
          <a {{action 'expand'}}>{{i.category}}</a>
        </td>
        <td>
          {{i.pk}}
        </td>
        <td>
          {{#if isExpanded}}
            <button {{action "deleteCategory"}}>Edit</button>
            <button {{action "deleteCategory"}}>Delete</button>
          {{else}}
            <button {{action 'expand'}}>Actions</button>
          {{/if}}
        </td>
      </tr>
    {{/each}}

Since stackoverflow, is not letting me post without adding more text, I would also like to know how to show all the products associated with the category, on the same route (same page), by clicking on each category?

Cheers and thank you.