title: Extract sub-elements from XPATH Fetch Page pipe
body: <p>I'm hoping to convert the content of 3 adjacent <code>TD</code> elements in a <code>TR</code> using Yahoo Pipes to a comma-delimited list of values.  Source: <a href="http://epic.usergroup.healthitsocial.com/page/epic-hospitals" rel="nofollow noreferrer">Epic Systems Hospitals</a>.</p>
  
  <p>HTML snippet:</p>
  
  <p>...</p>
  
  <pre><code>&lt;table width="623" cellspacing="0" cellpadding="0" border="0"&gt;
    &lt;colgroup&gt;
      &lt;tbody&gt;
        &lt;tr height="20"&gt;
          &lt;td width="425" height="20"&gt;Institution 0&lt;/td&gt;
          &lt;td width="134"&gt;Minneapolis&lt;/td&gt;
          &lt;td width="64"&gt;MN&lt;/td&gt;
        &lt;/tr&gt;
        &lt;tr height="20"&gt;
          &lt;td height="20"&gt;Institution 1&lt;/td&gt;
          &lt;td&gt;Philadelphia&lt;/td&gt;
          &lt;td&gt;PA&lt;/td&gt;
        &lt;/tr&gt;
  </code></pre>
  
  <p>...</p>
  
  <p>I've used the "XPath fetch page" source to correctly isolate the <code>TR</code> elements using an XPATH=<code>//tr[@height='20']</code>.</p>
  
  <p>I'm having difficulty getting the <code>TD</code> elements, however.  It's not obvious to me which component I should be using, so I chose a Sub-element with the '<a href="http://pipes.yqlblog.net/2012/04/24/new-module-xpath-fetch-page/" rel="nofollow noreferrer">special variable substitution</a>' syntax.  Unfortunately, <code>${td.0.content}</code> doesn't work.</p>
  
  <p>What am I not understanding?</p>
  
  <p>** edit **</p>
  
  <p>My goal is to create an XML stream that resembles:</p>
  
  <pre><code>&lt;institutions&gt;
    &lt;institution name='Institution 0' city='Minneapolis' region='MN'/&gt;
    &lt;institution name='Institution 1' city='Philadelphia' region='PA'/&gt;
    ...
  &lt;institutions/&gt;
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/jwR3U.png" alt="enter image description here"></p>