title: Get name of an HTML element with PHP parsing
body: <p>so say I have an HTML page like this.</p>
  
  <pre><code>&lt;input type="text" name="name" /&gt;
  &lt;input type="hidden" name="test" value="test_result1" /&gt;
  &lt;input type="hidden" name="test2" value="test_result2" /&gt;
  </code></pre>
  
  <p>I want to parse that HTML page (from a url, using file_get_contents?), then get the names of the input elements that have the type "hidden".</p>
  
  <p>Basically what I want parsed from that page is</p>
  
  <pre><code>test
  test2
  </code></pre>
  
  <p>Is there a way to do this? I looked into some parsing libraries (like SimpleHTMLDom), but I just couldn't do it.</p>