/*
* The MIT License
*
* Copyright (c) 2012, CloudBees, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package jenkins;
import hudson.ExtensionComponent;
import hudson.ExtensionFinder;
import hudson.ExtensionList;
import hudson.ExtensionPoint;
import hudson.model.AdministrativeMonitor;
import hudson.model.Describable;
import hudson.model.Descriptor;
import hudson.model.DescriptorVisibilityFilter;
/**
* Filters out {@link ExtensionComponent}s discovered by {@link ExtensionFinder}s,
* as if they were never discovered.
*
* <p>
* This is useful for those who are deploying restricted/simplified version of Jenkins
* by reducing the functionality.
*
* <p>
* Because of the way {@link ExtensionFinder} works, even when an extension component
* is rejected by a filter, its instance still gets created first.
*
* @author Kohsuke Kawaguchi
* @since 1.472
* @see DescriptorVisibilityFilter
* @see ExtensionComponentSet#filtered()
*/
public abstract class ExtensionFilter implements ExtensionPoint {
/**
* Checks if a newly discovered extension is allowed to participate into Jenkins.
*
* <p>
* To filter {@link Descriptor}s based on the {@link Describable} subtypes, do as follows:
*
* <pre>
* return !component.isDescriptorOf(Builder.class);
* </pre>
*
* @param type
* The type of the extension that we are discovering. This is not the actual instance
* type, but the contract type, such as {@link Descriptor}, {@link AdministrativeMonitor}, etc.
* @return
* true to let the component into Jenkins. false to drop it and pretend
* as if it didn't exist. When any one of {@link ExtensionFilter}s veto
* a component, it gets dropped.
*/
public abstract <T> boolean allows(Class<T> type, ExtensionComponent<T> component);
public static <T> boolean isAllowed(Class<T> type, ExtensionComponent<T> component) {
// to avoid infinite recursion, those extension points are handled differently.
if (type==ExtensionFilter.class || type==ExtensionFinder.class)
return true;
for (ExtensionFilter f : all())
if (!f.allows(type, component))
return false;
return true;
}
/**
* All registered {@link ExtensionFilter} instances.
*/
public static ExtensionList<ExtensionFilter> all() {
return ExtensionList.lookup(ExtensionFilter.class);
}
}