title: XSLT - Is there a way to append to attributes added with <xsl:attribute>?
body: <p>Simplified example:</p>
  
  <pre><code>&lt;xsl:template name="helper"&gt;
    &lt;xsl:attribute name="myattr"&gt;first calculated value&lt;/xsl:attribute&gt;
  &lt;/xsl:template&gt;
  
  &lt;xsl:template match="/&gt;
    &lt;myelem&gt;
      &lt;xsl:call-template name="helper" /&gt;
      &lt;xsl:attribute name="myattr"&gt;second calculated value&lt;/xsl:attribute&gt;
    &lt;/myelem&gt;
  &lt;/xsl:template&gt;
  </code></pre>
  
  <p>Is there some way for the second  to <em>append</em> the second calculated value to the same <code>myattr</code> attribute in the result node?</p>
  
  <p>I've seen it is possible to use an attribute value template if the target attribute is in the source xml, but can I reference somehow the value of the attribute I have earlier appended to the result node?</p>
  
  <p>Thanks in advance!</p>