# Property Testers

###### Identifier:

org.eclipse.core.expressions.propertyTesters

###### Since:

3.0

###### Description:

This extension point allows to add properties to an already existing type. Those properties can then be used inside the expression language's test expression element.

###### Configuration Markup:

<!ELEMENT extension (propertyTester*)>

<!ATTLIST extension

point CDATA #REQUIRED

id CDATA #IMPLIED

name CDATA #IMPLIED>

- point - a fully qualified identifier of the target extension point
- id - an optional identifier of the extension instance
- name - an optional name of the extension instance

<!ELEMENT propertyTester EMPTY>

<!ATTLIST propertyTester

id CDATA #REQUIRED

type CDATA #REQUIRED

namespace CDATA #REQUIRED

properties CDATA #REQUIRED

class CDATA #REQUIRED>

- id - unique identifier for the property tester
- type - the type to be extended by this property tester
- namespace - a unique id determining the name space the properties are added to
- properties - a comma separated list of properties provided by this property tester
- class - the name of the class that implements the testing methods. The class must be public and extend `org.eclipse.core.expressions.PropertyTester` with a public 0-argument constructor.

###### Examples:

The following is an example of a property tester contribution:

      <extension point="org.eclipse.core.expressions.propertyTesters">
        <propertyTester
          id="org.eclipse.jdt.ui.IResourceTester"
          type="org.eclipse.core.resources.IResource"
          namespace="org.eclipse.jdt.ui"
          properties="canDelete"
          class="org.eclipse.jdt.ui.internal.ResourceTester">
        </propertyTester>
      </extension>

###### API Information:

The contributed class must extend `org.eclipse.core.expressions.PropertyTester`

Copyright (c) 2001, 2004 IBM Corporation and others.
All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse Public License v1.0 which accompanies this distribution, and is available at http://www.eclipse.org/legal/epl-v10.html