title: Sending one time event to child components
body: <p>Im struggling to implement something which I think is pretty easy.</p>
  
  <p>In my Vue app I loop through a list. Each list item is a child component. Each list item has an expand/collapse button. That works fine, but I want to be able to close all open items from the parent and I don't seem to be able to get that working as I would like.</p>
  
  <p>The expand/collapse is controlled via a variable called <code>isOpen</code> so</p>
  
  <pre><code>&lt;div v-if="isOpen"&gt;Something here&lt;/div&gt;
  </code></pre>
  
  <p>I have tried using a computed property instead of the isOpen and passing props but that issue is I think it needs to act more like an event.</p>
  
  <p>Consider three open list items. If the list items are controlled by a prop, and setting it to <code>false</code> closes the items, when an item is reopened, the prop is still <code>false</code> so therefore will not work a second time. I know I could change it back on the parent, but it seems wrong.</p>
  
  <p>Whats the best way to accomplish this?</p>