====== Core Expressions ======
Core expressions are declared in the plugin.xml file.

===== Selection of Specific Class =====
To check if the selection is an instance of a specific class.

<sxh xml>
    <extension
         point="org.eclipse.core.expressions.definitions">
      <definition
            id="miworkplace.ui.core.expression.isConnection">
         <with
               variable="org.eclipse.ui.selection">
            <iterate
                  ifEmpty="false"
                  operator="or">
               <instanceof
                     value="miworkplace.connection.api.IConnection">
               </instanceof>
            </iterate>
         </with>
      </definition>
   </extension>
</sxh>

The bundle ''org.eclipse.core.expressions'' needs to be added as a dependency to get the core expression extension point.

{{tag>eclipse e4}}