<p>
This rule allows to define some homemade Java rules with help of an XPath expression.
</p>

<p>
Issues are created depending on the return value of the XPath expression. If the XPath expression returns:
</p>
<ul>
  <li>a single or list of AST nodes, then a line issue with the given message is created for each node</li>
  <li>a boolean, then a file issue with the given message is created only if the boolean is true</li>
  <li>anything else, no issue is created</li>
</ul>

<p>
Here is an example of an XPath expression to log an issue on each if statement : //ifStatement
</p>