RatingService Phase 1.

The RatingService will allow users to apply ratings to content nodes in the repository.
  There will be a number of built-in Rating Schemes and support to add more by the usual extension mechanism.
  Out of the box, we envision a 'likes' scheme (user X likes this document) and a 'star' rating
    (user X gave this document 3 out of 5 stars).

  Content model for ratings.
  Spring config includes two out-of-the-box rating schemes
  Various basic infrastructure classes for Ratings, RatingSchemes and the service itself.
  Basic CRUD for ratings in a Java foundation layer.
  Associated JUnit tests.

The next contribution will add support for per-node average and total ratings and associated tests.


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@21000 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/service/cmr/rating/RatingService.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2005-2010 Alfresco Software Limited.
+ *
+ * This file is part of Alfresco
+ *
+ * Alfresco 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco 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 Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.alfresco.service.cmr.rating;
+
+import java.util.Map;
+
+import org.alfresco.service.NotAuditable;
+import org.alfresco.service.PublicService;
+import org.alfresco.service.cmr.repository.NodeRef;
+
+/**
+ * The Rating service. TODO
+ * 
+ * @author Neil McErlean
+ * @since 3.4
+ */
+@PublicService
+public interface RatingService
+{
+    /**
+     * Returns the available {@link RatingScheme rating schemes} keyed by name.
+     * 
+     * @return The {@link RatingScheme rating schemes}.
+     */
+    @NotAuditable
+    Map<String, RatingScheme> getRatingSchemes();
+
+    /**
+     * Returns the named {@link RatingScheme rating scheme} if there is one.
+     * 
+     * @param ratingSchemeName name of the rating scheme.
+     * @return The {@link RatingScheme rating schemes} if one of that name is registered,
+     *         else <code>null</code>.
+     */
+    @NotAuditable
+    RatingScheme getRatingScheme(String ratingSchemeName);
+
+    /**
+     * This method applies the given rating to the specified target node. If a rating
+     * from the current user in the specified scheme already exists, it will be replaced.
+     * 
+     * @param targetNode the node to which the rating is to be applied.
+     * @param rating the rating which is to be applied.
+     * @param ratingSchemeName the name of the rating scheme to use.
+     * 
+     * @throws RatingServiceException if the rating is not within the range defined by the named scheme
+     *                                or if the named scheme is not registered.
+     * @see RatingService#getRatingSchemes()
+     * @see RatingScheme
+     */
+    @NotAuditable
+    void applyRating(NodeRef targetNode, int rating, String ratingSchemeName) throws RatingServiceException;
+
+    /**
+     * This method gets the {@link Rating} applied by the current user to the specified node in the specified
+     * {@link RatingScheme} - if there is one.
+     * 
+     * @param targetNode the node on which the rating is sought.
+     * @param ratingScheme the rating scheme to use.
+     * 
+     * @return the Rating object if there is one, else <code>null</code>.
+     * @see RatingService#getRatingSchemes()
+     * @see RatingScheme
+     */
+    @NotAuditable
+    
+    // TODO Get average/total ratings on node
+    
+    Rating getRatingByCurrentUser(NodeRef targetNode, RatingScheme ratingScheme);
+    
+    /**
+     * This method removes any {@link Rating} applied by the current user to the specified node in the specified
+     * {@link RatingScheme}.
+     * 
+     * @param targetNode the node from which the rating is to be removed.
+     * @param ratingScheme the rating scheme to use.
+     * 
+     * @return the deleted Rating object if there was one, else <code>null</code>.
+     * @see RatingService#getRatingSchemes()
+     * @see RatingScheme
+     */
+    @NotAuditable
+    Rating removeRatingByCurrentUser(NodeRef targetNode, RatingScheme ratingScheme);
+}