gistfile1.txt

import Ember from 'ember';

export default Ember.Component.extend({
  didReceiveAttrs() {
    this._super(...arguments);
    const viz = this.get('viz');
    Ember.Logger.info(viz.get('type')); // <--here data is undefined?
  },
});

show.hbs

{{#each model.visualizations as |v idx|}}
<div id="vis-{{idx}}">
    <div class="chart"></div>
</div>
<p>id: {{v.id}}, type: {{v.type}}</p> <--- type printed here without issue

{{chart-widget viz=v}} {{/each}}