title: What does ExtJS ComboBox triggerAction: "all" really do?
body: <p>I tried to create a simple ComboBox:</p>
  
  <pre><code>var combo1 = new Ext.form.ComboBox({
    store: [1,2,3],
    renderTo: document.body
  });
  </code></pre>
  
  <p>But written this way it acts strangely:</p>
  
  <ul>
  <li>When you first time pop open the dropdown, it offers three choices.</li>
  <li>You choose one.</li>
  <li>But when you after that try to change your selection, the dropdown only offers one choice - the one you previously selected.</li>
  </ul>
  
  <p>I compared my code to the <a href="http://extjs.com/deploy/dev/examples/form/combos.html" rel="noreferrer">samples</a> on Ext homepage and discovered that adding <code>triggerAction: "all"</code> solves my problem:</p>
  
  <pre><code>var combo2 = new Ext.form.ComboBox({
    triggerAction: "all",
    store: [1,2,3],
    renderTo: document.body
  });
  </code></pre>
  
  <p>ExtJS documentation for <code>triggerAction</code> doesn't tell me a lot:</p>
  
  <blockquote>
    <p>The action to execute when the trigger is clicked.
    Use 'all' to run the query specified by the allQuery
    config option (defaults to 'query')</p>
  </blockquote>
  
  <p>I haven't specified the allQuery option. Actually, I don't want to perform a query to the server at all.</p>
  
  <p>So what does this <code>triggerAction</code> really do?</p>
  
  <p>And is setting it to <code>"all"</code> really what I should do when I just want a simple static combobox?</p>