RelationshipType.java

/*
 * Copyright (C) 2003-2009 eXo Platform SAS.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.chromattic.api;

/**
 * The type of a relationship. It defines the semantics about how the relationship is maintained between
 * nodes.
 *
 * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
 * @version $Revision$
 * @see org.chromattic.api.annotations.OneToMany
 * @see org.chromattic.api.annotations.ManyToOne
 */
public enum RelationshipType {

  /**
   * A hierarchic relationship uses the natural parent child relationship to associate nodes. It is valid either
   * for one to one or one to many relationship.
   */
  HIERARCHIC,

  /**
   * A reference relationship uses reference a typed property to associate nodes. It is only valid for one to many
   * relationships.
   */
  REFERENCE,

  /**
   * A path relationship uses path a typed property to associate nodes. It is only valid for one to many
   * relationships.
   */
  PATH,

  /**
   * <p>An embedded relationship defines a relationship between two types that are have a relationship between their
   * node types.</p>
   *
   * <p>The owner side of the relationship must be a primary node type, the owned side of the relationship can be any
   * node type. Embedded relationship only exist for {@link org.chromattic.api.annotations.OneToOne} relationships</p>
   *
   * <p>When the owned side is a primary node type, the owned node type must be super node type of the owner node type. The
   * relationship is thereby statically defined.</p>
   *
   * <p>When the owned side is a mixin type, the relationship exists when the owner side has the mixin of the owned side.
   * The relationship is static when the owner node type defines the owned mixin type has a super node type directly or
   * indirectly. The relationship is dynamic when the owner node type does not define the owned mixin type has a super node
   * type directly and indirectly, therefore the relationship can be created or destroyed at runtime.</p>
   */
  EMBEDDED

}