DTRules/src/main/java/com/dtrules/trace/TraceNode.java

   1 /*
   2  * $Id$
   3  *
   4  * Copyright 2004-2007 MTBJ, Inc.
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *      http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  */
  18
  19 package com.dtrules.trace;
  20
  21 import com.dtrules.interpreter.RInteger;
  22 import com.dtrules.interpreter.RName;
  23
  24 /**
  25  * A trace node allows two kinds of navigation acorss changes recorded in
  26  * a DTRules Trace file.   One mode is a tree, and one mode is linear.  In
  27  * fact, all changes occur serially within a decision table thread.  Yet all
  28  * changes occur with in a hierarchy of Decision Table execution.
  29  *
  30  * The parent of all nodes is a root node. The initialization node holds the
  31  * initial values (includeing data inserted into a ruleset)
  32  *
  33  * The changes are kept as nodes
  34  */
  35 public interface TraceNode {
  36
  37     /**
  38      * These are the hierarchy operators.
  39      */
  40
  41     /** getParent() -- return the parent node, usually a decisiontable.  But it
  42      * could be the root node, or the initialization node.
  43      * @return
  44      */
  45     TraceNode getParent();
  46     /**
  47      * Get the firstChild()
  48      * @return
  49      */
  50     TraceNode getFirstChild();
  51     /**
  52      * Get the next();
  53      * Returns a null if no more children;
  54      * @return
  55      */
  56     TraceNode getNext();
  57     /**
  58      * Get the perivious node,
  59      * @return
  60      */
  61     TraceNode getPrevious();
  62
  63     /**
  64      * These are the linear access methods.  All the changes are organized
  65      * in a linear list.
  66      */
  67     /**
  68      * Get the next Change Node
  69      * @return
  70      */
  71     TraceNode getNextChange();
  72     /**
  73      * Get the previous Change Node
  74      * @return
  75      */
  76     TraceNode getPreviousChange();
  77
  78
  79     /**
  80      * Change Operators
  81      */
  82     void setOldValues();
  83     void setNewValues();
  84     /**
  85      * Returns the Name for the Attribute that changed (or a null if
  86      * this isn't a change to an Entity).
  87      */
  88     RName getAttribute();
  89     /**
  90      * Returns the index for the Attribute that changed (or a null if
  91      * this isn't a change to an Element of an Array).
  92      */
  93     RInteger getIndex();
  94 }