001/**
002 * Copyright 2005-2016 The Kuali Foundation
003 *
004 * Licensed under the Educational Community License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/ecl2.php
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.kuali.rice.krms.framework.engine;
017
018import java.util.Map;
019
020import org.kuali.rice.krms.api.engine.ExecutionOptions;
021import org.kuali.rice.krms.api.engine.SelectionCriteria;
022import org.kuali.rice.krms.api.engine.Term;
023
024/**
025 * Loads a {@link Context} for the given set of criteria.  Applications who
026 * want to provide their own means for creating a context and supplying it to
027 * the KRMS engine can do so by implementing a custom ContextProvider. 
028 * 
029 * @see Context
030 * 
031 * @author Kuali Rice Team (rice.collab@kuali.org)
032 *
033 */
034public interface ContextProvider {
035
036        /**
037         * Loads the context for the given selection criteria, facts, and execution
038         * options.  If no context can be located based on the given criteria, then
039         * this method should return null.
040         * 
041         * <p>In the case where multiple Contexts could potentially be identified
042         * from the same set of selection criteria, it is up to the implementer
043         * of the ContextProvider to ensure that the most appropriate Context is
044         * returned.  Or alternatively, an exception could be thrown indicating
045         * context ambiguity.
046         * 
047         * <p>The sectionCriteria, facts, and executionOptions which are passed to
048         * this method should never be null.  However, they might be empty.
049         * 
050         * @param selectionCriteria the criteria to use during the selection phase of engine operation
051         * @param facts the set of facts that are supplied to the engine at execution time
052         * @param executionOptions a collection of options that can be used to customize engine execution behavior
053         * 
054         * @return the context which matches the given criteria, or null if no context matches
055         */
056        public Context loadContext(SelectionCriteria selectionCriteria, Map<Term, Object> facts, ExecutionOptions executionOptions);
057        
058}