/*******************************************************************************
 *
 * Copyright (c) 2004-2009, Oracle Corporation
 *
 * 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
 *
 * Contributors:
 *
 *
 *
 *
 *******************************************************************************/ 

package hudson.model;

import hudson.Extension;
import hudson.ExtensionList;
import hudson.ExtensionPoint;
import hudson.tasks.BuildStep;

import java.util.Collection;

/**
 * Extension point for inserting transient {@link Action}s into
 * {@link AbstractProject}s.
 *
 * <p> Actions of projects are primarily determined by {@link BuildStep}s that
 * are associated by configurations, but sometimes it's convenient to be able to
 * add actions across all or many projects, without being invoked through
 * configuration. This extension point provides such a mechanism.
 *
 * Actions of {@link AbstractProject}s are transient — they will not be
 * persisted, and each time Hudson starts or the configuration of the job
 * changes, they'll be recreated. Therefore, to maintain persistent data per
 * project, you'll need to do data serialization by yourself. Do so by storing a
 * file under {@link AbstractProject#getRootDir()}.
 *
 * <p> To register your implementation, put {@link Extension} on your subtype.
 *
 * @author Kohsuke Kawaguchi
 * @since 1.327
 * @see Action
 */
public abstract class TransientProjectActionFactory implements ExtensionPoint {

    /**
     * Creates actions for the given project.
     *
     * @param target The project for which the action objects are requested.
     * Never null.
     * @return Can be empty but must not be null.
     */
    public abstract Collection<? extends Action> createFor(AbstractProject target);

    /**
     * Returns all the registered {@link TransientProjectActionFactory}s.
     */
    public static ExtensionList<TransientProjectActionFactory> all() {
        return Hudson.getInstance().getExtensionList(TransientProjectActionFactory.class);
    }
}