/*
 * Copyright (c) OSGi Alliance (2013, 2014). All Rights Reserved.
 *
 * 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.osgi.service.component.runtime.dto;

import org.osgi.dto.DTO;

/**
 * A representation of a declared reference to a service.
 * 
 * @since 1.3
 * @NotThreadSafe
 * @author $Id: a02ee5ad7b783a19bf7e1d8f9dcc6f44685ccd41 $
 */
public class ReferenceDTO extends DTO {

	/**
	 * Constant for the lookup strategy
	 * 
	 * @see #strategy
	 */
	String			STRATEGY_LOOKUP			= "LOOKUP";

	/**
	 * Constant for the method strategy
	 * 
	 * @see #strategy
	 */
	String			STRATEGY_METHOD			= "METHOD";

	/**
	 * Constant for the field replace strategy
	 * 
	 * @see #strategy
	 */
	String			STRATEGY_FIELD_REPLACE	= "FIELD_REPLACE";

	/**
	 * Constant for the field update strategy
	 * 
	 * @see #strategy
	 */
	String			STRATEGY_FIELD_UPDATE	= "FIELD_UPDATE";

	/**
	 * The strategy of the reference.
	 * 
	 * <p>
	 * This field returns the strategy used for this reference. If the value is
	 * either {@code #STRATEGY_FIELD_REPLACE} or {@code #STRATEGY_FIELD_UPDATE},
	 * {@link #field} returns the name of the field. If the strategy is
	 * {@code #STRATEGY_METHOD} {@link #bind}, {@link #unbind}, and
	 * {@link #updated} return the name of the methods.
	 *
	 * @see #STRATEGY_FIELD_REPLACE
	 * @see #STRATEGY_FIELD_UPDATE
	 * @see #STRATEGY_LOOKUP
	 * @see #STRATEGY_METHOD
	 */
	public String	strategy;

	/**
	 * The name of the reference.
	 * 
	 * <p>
	 * This is declared in the {@code name} attribute of the {@code reference}
	 * element. This must be the default name if the component description does
	 * not declare a name for the reference.
	 */
	public String	name;

	/**
	 * The service interface of the reference.
	 * 
	 * <p>
	 * This is declared in the {@code interface} attribute of the
	 * {@code reference} element.
	 */
	public String	interfaceName;

	/**
	 * The cardinality of the reference.
	 * 
	 * <p>
	 * This is declared in the {@code cardinality} attribute of the
	 * {@code reference} element. This must be the default cardinality if the
	 * component description does not declare a cardinality for the reference.
	 */
	public String	cardinality;

	/**
	 * The policy of the reference.
	 * 
	 * <p>
	 * This is declared in the {@code policy} attribute of the {@code reference}
	 * element. This must be the default policy if the component description
	 * does not declare a policy for the reference.
	 */
	public String	policy;

	/**
	 * The policy option of the reference.
	 * 
	 * <p>
	 * This is declared in the {@code policy-option} attribute of the
	 * {@code reference} element. This must be the default policy option if the
	 * component description does not declare a policy option for the reference.
	 */
	public String	policyOption;

	/**
	 * The target of the reference.
	 * 
	 * <p>
	 * This is declared in the {@code target} attribute of the {@code reference}
	 * element. This must be {@code null} if the component description does not
	 * declare a target for the reference.
	 */
	public String	target;

	/**
	 * The name of the bind method of the reference.
	 * 
	 * <p>
	 * This is declared in the {@code bind} attribute of the {@code reference}
	 * element. This must be {@code null} if the component is not using the
	 * method strategy or the component description does not declare a bind
	 * method for the reference.
	 */
	public String	bind;

	/**
	 * The name of the unbind method of the reference.
	 * 
	 * <p>
	 * This is declared in the {@code unbind} attribute of the {@code reference}
	 * element. This must be {@code null} if the component is not using the
	 * method strategy or the component description does not declare an unbind
	 * method for the reference.
	 *
	 * @see #strategy
	 */
	public String	unbind;

	/**
	 * The name of the updated method of the reference.
	 * 
	 * <p>
	 * This is declared in the {@code updated} attribute of the
	 * {@code reference} element. This must be {@code null} if the component is
	 * not using the method strategy or the component description does not
	 * declare an updated method for the reference.
	 * 
	 * @see #strategy
	 */
	public String	updated;

	/**
	 * The name of the field of the reference.
	 * 
	 * <p>
	 * This is declared in the {@code field} attribute of the {@code reference}
	 * element. This must be {@code null} if the component is using the lookup
	 * or method strategy.
	 * 
	 * @see #strategy
	 */
	public String	field;

	/**
	 * The scope of the reference.
	 * 
	 * <p>
	 * This is declared in the {@code scope} attribute of the {@code reference}
	 * element. This must be the default scope if the component description does
	 * not declare a scope for the reference.
	 */
	public String	scope;
}