title: XSL / XPath expression to check if a node contains at least one non-empty child
body: <p>I need to check if an XML node has at least one non-empty child. Applied to this XML the expression should return <code>true</code></p>
  
  <pre><code>&lt;xml&gt;
      &lt;node&gt;
         &lt;node1/&gt;
         &lt;node2/&gt;
         &lt;node3&gt;value&lt;/node3&gt;
      &lt;/node&gt;
  &lt;/xml&gt;
  </code></pre>
  
  <p>I tried to use this expression: <code>&lt;xsl:if test="not(/xml/node/child::* = '')"&gt;</code> but it seems to check if <strong>all</strong> children are not empty.</p>
  
  <p>How can I write an expression which returns <code>true</code> if <strong>at least one</strong> element is not empty? Is there a way to do this without creating another template to iterate over node chldren?</p>
  
  <p><strong>UPD:</strong> I'm thinking of counting non-empty nodes like<br>
  <code>test="count(not(/xml/node/child::* = '')) &amp;gt; '0'"</code><br>
  but somehow just can't make it work right. This expression is not a well-formed one.</p>