/*
 * Copyright 2003,2004 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.pluto.internal;

import org.apache.pluto.internal.InternalPortletPreference;
import org.apache.pluto.descriptors.portlet.PortletDD;
import org.apache.pluto.descriptors.servlet.ServletDD;

import javax.portlet.PreferencesValidator;
import javax.portlet.ValidatorException;

/**
 * The PortletEntity encapsulates all data pertaining to a single portlet
 * instance.  This instance may appear zero or more times per user. The
 * PortletEntity consists of two primary peices of information, the Portlet
 * Definition as defined by the {@link PortletDD} and the Wrapping Servlet
 * information as defined by the{@link ServletDD}
 * 
 * @author <a href="mailto:zheng@apache.org">ZHENG Zhong</a>
 * @author <a href="mailto:ddewolf@apache.org">David H. DeWolf</a>
 */
public interface PortletEntity {
	
    /**
     * Returns the URI to the controller servlet that wraps this portlet.
     * @return the URI to the controller servlet that wraps this portlet.
     */
    public String getControllerServletUri();
    
    /**
     * Returns an array of default preferences of this portlet. The default
     * preferences are retrieved from the portlet application descriptor.
     * <p>
     * Data retrieved from <code>portlet.xml</code> are injected into the domain
     * object <code>PortletPreferenceDD</code>. This method converts the domain
     * objects into <code>PortletPreference</code> objects.
     * </p>
     * <p>
     * Note that if no value is bound to a given preference key,
     * <code>PortletPreferenceDD.getValues()</code> will return an empty string
     * list, but the value array of <code>PortletPreference</code> should be set
     * to null (instead of an empty array).
     * </p>
     * <p>
     * This method never returns null, but the values held by PortletPreference
     * may be null.
     * </p>
     * @return the preference set
     * 
     * @see org.apache.pluto.descriptors.portlet.PortletPreferenceDD
     */
    public InternalPortletPreference[] getDefaultPreferences();

    /**
     * Returns the portlet description. The return value cannot be NULL.
     * @return the portlet description.
     */
    public PortletDD getPortletDefinition();
    
    /**
     * Returns the preferences validator instance for this portlet.
     * One validator instance is created per portlet definition.
     * @return the preferences validator instance for this portlet.
     * @throws ValidatorException  if fail to instantiate the validator.
     */
    public PreferencesValidator getPreferencesValidator()
    throws ValidatorException;
    
}