# Preferences

###### Identifier:

org.eclipse.core.runtime.preferences

###### Since:

3.0

###### Description:

The preferences extension point allows plug-ins to add new preference scopes to the Eclipse preference mechanism as well as specify the class to run to initialize default preference values at runtime.

###### Configuration Markup:

<!ELEMENT extension (scope* , initializer* , modifier*)>

<!ATTLIST extension

point CDATA #REQUIRED

id CDATA #IMPLIED

name CDATA #IMPLIED

>

<!ELEMENT scope EMPTY>

<!ATTLIST scope

name CDATA #REQUIRED

class CDATA #REQUIRED

>

Element describing a client's definiton of a new preference scope.

- name - The name of the scope.
- class - The name of the class.

<!ELEMENT initializer EMPTY>

<!ATTLIST initializer

class CDATA #REQUIRED

>

Element which defines the class to use for runtime preference initialization.

- class - The name of the class.

<!ELEMENT modifier EMPTY>

<!ATTLIST modifier

class CDATA #REQUIRED

>

Element which defines the class to use for preference modification listening.

- class - The name of the class.

###### Examples:

Following is an example of a preference scope declaration. This example declares that this plug-in will provide a preference implementation for the scope "foo". It also declares that when the default values are loaded for this plug-in, the class "MyPreferenceInitializer" contains code to be run to initialize preference default values at runtime.

          <extension point="org.eclipse.core.runtime.preferences">
             <scope name="foo" class="com.example.FooPrefs"/>
             <initializer class="com.example.MyPreferenceInitializer"/>
             <modifier class="com.example.MyModifyListener"/>
          </extension>

###### API Information:

Supplied preference initializers must subclass `org.eclipse.core.runtime.preferences.AbstractPreferenceInitializer`. Preference modify listeners must subclass `org.eclipse.core.runtime.preferences.PreferenceModifyListener`. The preference service (obtained by calling `org.eclipse.core.runtime.Platform.getPreferencesService()`) is the hook into the Eclipse preference mechanism.

###### Supplied Implementation:

The org.eclipse.core.runtime plug-in provides preference implementations for the "configuration", "instance", and "default" scopes. The org.eclipse.core.resources plug-in provides an implementation for "project" preferences.

Copyright (c) 2004, 2005 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