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1   /**
2    * Copyright 2005-2012 The Kuali Foundation
3    *
4    * Licensed under the Educational Community License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    * http://www.opensource.org/licenses/ecl2.php
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.kuali.rice.krms.api.engine;
17  
18  import java.util.Map;
19  import java.util.Set;
20  
21  /**
22   * The ExecutionEnvironment manages contextual information which is made available to
23   * different components of the rules engine during execution.  Facts can be retrieved
24   * from and published to the environment.  It also provides a reference to the
25   * {@link EngineResults} or tracking engine activity and returning values back to
26   * the client of the rules engine.
27   * 
28   * @author Kuali Rice Team (rice.collab@kuali.org)
29   *
30   */
31  public interface ExecutionEnvironment {
32  	
33  	/**
34  	 * Returns the selection criteria that was used to initialize the environment.
35  	 * 
36  	 * @return the selection criteria for this environment
37  	 */
38  	public SelectionCriteria getSelectionCriteria();
39  	
40  	/**
41  	 * Returns an immutable Map of facts available within this environment.
42  	 * 
43  	 * @return the facts in this environment
44  	 */
45  	public Map<Term, Object> getFacts();
46  
47  	/**
48  	 * Publishes a new fact
49  	 * 
50  	 * @param factName name of the fact to publish
51  	 * @param factValue value of the fact to publish
52  	 * // TODO: we don't support updating facts, refactor this method
53  	 * @return true if an existing fact was updated, false if this was a new fact
54  	 */
55  	public boolean publishFact(Term factName, Object factValue);
56  
57      /**
58       * Add a {@link TermResolver}
59       * @param termResolver
60       */
61  	public void addTermResolver(TermResolver<?> termResolver);
62  
63      /**
64       * Resolve
65       * @param term {@link Term}
66       * @param caller
67       * @return <T> T
68       * @throws {@link TermResolutionException}
69       */
70  	public <T> T resolveTerm(Term term, Object caller) throws TermResolutionException;
71  
72      /**
73       * Return a set of Term for the given value
74       * @param caller
75       * @return Set<Term>
76       */
77  	public Set<Term> getTermsForCaller(Object caller);
78  
79      /**
80       * Return the {@link ExecutionOptions}
81       * @return {@link ExecutionOptions}
82       */
83  	public ExecutionOptions getExecutionOptions();
84  
85      /**
86       * Return the {@link EngineResults}
87       * @return {@link EngineResults}
88       */
89  	public EngineResults getEngineResults();
90  	
91  }