title: PrimeFaces 3.4 Charts datatipFormat
body: <p>today I wanted to try the new PrimeFaces release 3.4.RC1.
  For charts there is a new attribute called datatipFormat.</p>
  
  <p>I want to show only the value (y-axis) in a line chart as datatip.
  Like this:</p>
  
  <pre><code>&lt;p:lineChart value="#{...}" datatipFormat="y-value"/&gt;
  </code></pre>
  
  <p>What do I have to do to show only this? 
  I could not find an example with a template String.</p>
  
  <p>Best Regards
  Veote</p>