title: XPath filter not empty child element
body: <p>I need to filter a XPath expression to grab only a certain attribute as not empty.</p>
  
  <p>I tried this:</p>
  
  <pre><code>&lt;xsl:template match="DocumentElement/QueryResults[string(@FileName)]"&gt;
  </code></pre>
  
  <p>and this:</p>
  
  <pre><code>&lt;xsl:template match="DocumentElement/QueryResults[string-length(@FileName)&gt;0]"&gt;
  </code></pre>
  
  <p>but it did not work. I need the same kind of data returning from the folloing XPath expression...</p>
  
  <pre><code>&lt;xsl:template match="DocumentElement/QueryResults"&gt;
  </code></pre>
  
  <p>... but filtered to avoid items with empty attribute @FileName.</p>
  
  <p>Thanks!</p>