##### Coverage Report - org.apache.commons.scxml.env.jexl.JexlEvaluator

Classes in this File | Line Coverage | Branch Coverage | Complexity
JexlEvaluator |
81% |
100% |
| 4.833333333333333;4.833

1 |  |
     /*
2 |  |
      * Licensed to the Apache Software Foundation (ASF) under one or more
3 |  |
      * contributor license agreements.  See the NOTICE file distributed with
4 |  |
      * this work for additional information regarding copyright ownership.
5 |  |
      * The ASF licenses this file to You under the Apache License, Version 2.0
6 |  |
      * (the "License"); you may not use this file except in compliance with
7 |  |
      * the License.  You may obtain a copy of the License at
8 |  |
      *
9 |  |
      *     http://www.apache.org/licenses/LICENSE-2.0
10 |  |
      *
11 |  |
      * Unless required by applicable law or agreed to in writing, software
12 |  |
      * distributed under the License is distributed on an "AS IS" BASIS,
13 |  |
      * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 |  |
      * See the License for the specific language governing permissions and
15 |  |
      * limitations under the License.
16 |  |
      */
17 |  |
     package org.apache.commons.scxml.env.jexl;
18 |  |
19 |  |
     import java.io.Serializable;
20 |  |
     import java.util.ArrayList;
21 |  |
     import java.util.HashMap;
22 |  |
     import java.util.List;
23 |  |
     import java.util.Map;
24 |  |
     import java.util.regex.Pattern;
25 |  |
26 |  |
     import org.apache.commons.jexl.Expression;
27 |  |
     import org.apache.commons.jexl.ExpressionFactory;
28 |  |
     import org.apache.commons.scxml.Context;
29 |  |
     import org.apache.commons.scxml.Evaluator;
30 |  |
     import org.apache.commons.scxml.SCXMLExpressionException;
31 |  |
     import org.w3c.dom.Node;
32 |  |
33 |  |
     /**
34 |  |
      * Evaluator implementation enabling use of JEXL expressions in
35 |  |
      * SCXML documents.
36 |  |
      *
37 |  |
      */
38 |  |
     public class JexlEvaluator implements Evaluator, Serializable {
39 |  |
40 |  |
         /** Serial version UID. */
41 |  |
         private static final long serialVersionUID = 1L;
42 |  |
43 |  |
         /** Error message if evaluation context is not a JexlContext. */
44 |  |
         private static final String ERR_CTX_TYPE = "Error evaluating JEXL "
45 |  |
             + "expression, Context must be a org.apache.commons.jexl.JexlContext";
46 |  |
47 |  |
         /** Pattern for recognizing the SCXML In() special predicate. */
48 | 5 |
         private static Pattern inFct = Pattern.compile("In\\(");
49 |  |
         /** Pattern for recognizing the Commons SCXML Data() builtin function. */
50 | 5 |
         private static Pattern dataFct = Pattern.compile("Data\\(");
51 |  |
52 |  |
         /** Constructor. */
53 |  |
         public JexlEvaluator() {
54 | 36 |
             super();
55 | 36 |
         }
56 |  |
57 |  |
         /**
58 |  |
          * Evaluate an expression.
59 |  |
          *
60 |  |
          * @param ctx variable context
61 |  |
          * @param expr expression
62 |  |
          * @return a result of the evaluation
63 |  |
          * @throws SCXMLExpressionException For a malformed expression
64 |  |
          * @see Evaluator#eval(Context, String)
65 |  |
          */
66 |  |
         public Object eval(final Context ctx, final String expr)
67 |  |
         throws SCXMLExpressionException {
68 | 61 |
             if (expr == null) {
69 | 0 |
                 return null;
70 |  |
             }
71 | 61 |
             JexlContext jexlCtx = null;
72 | 61 |
             if (ctx instanceof JexlContext) {
73 | 61 |
                 jexlCtx = (JexlContext) ctx;
74 |  |
             } else {
75 | 0 |
                 throw new SCXMLExpressionException(ERR_CTX_TYPE);
76 |  |
             }
77 | 61 |
             Expression exp = null;
78 |  |
             try {
79 | 61 |
                 String evalExpr = inFct.matcher(expr).
80 |  |
                     replaceAll("_builtin.isMember(_ALL_STATES, ");
81 | 61 |
                 evalExpr = dataFct.matcher(evalExpr).
82 |  |
                     replaceAll("_builtin.data(_ALL_NAMESPACES, ");
83 | 61 |
                 exp = ExpressionFactory.createExpression(evalExpr);
84 | 61 |
                 return exp.evaluate(getEffectiveContext(jexlCtx));
85 | 0 |
             } catch (Exception e) {
86 | 0 |
                 throw new SCXMLExpressionException(e);
87 |  |
             }
88 |  |
         }
89 |  |
90 |  |
         /**
91 |  |
          * @see Evaluator#evalCond(Context, String)
92 |  |
          */
93 |  |
         public Boolean evalCond(final Context ctx, final String expr)
94 |  |
         throws SCXMLExpressionException {
95 | 51 |
             if (expr == null) {
96 | 0 |
                 return null;
97 |  |
             }
98 | 51 |
             JexlContext jexlCtx = null;
99 | 51 |
             if (ctx instanceof JexlContext) {
100 | 51 |
                 jexlCtx = (JexlContext) ctx;
101 |  |
             } else {
102 | 0 |
                 throw new SCXMLExpressionException(ERR_CTX_TYPE);
103 |  |
             }
104 | 51 |
             Expression exp = null;
105 |  |
             try {
106 | 51 |
                 String evalExpr = inFct.matcher(expr).
107 |  |
                     replaceAll("_builtin.isMember(_ALL_STATES, ");
108 | 51 |
                 evalExpr = dataFct.matcher(evalExpr).
109 |  |
                     replaceAll("_builtin.data(_ALL_NAMESPACES, ");
110 | 51 |
                 exp = ExpressionFactory.createExpression(evalExpr);
111 | 51 |
                 return (Boolean) exp.evaluate(getEffectiveContext(jexlCtx));
112 | 0 |
             } catch (Exception e) {
113 | 0 |
                 throw new SCXMLExpressionException(e);
114 |  |
             }
115 |  |
         }
116 |  |
117 |  |
         /**
118 |  |
          * @see Evaluator#evalLocation(Context, String)
119 |  |
          */
120 |  |
         public Node evalLocation(final Context ctx, final String expr)
121 |  |
         throws SCXMLExpressionException {
122 | 11 |
             if (expr == null) {
123 | 0 |
                 return null;
124 |  |
             }
125 | 11 |
             JexlContext jexlCtx = null;
126 | 11 |
             if (ctx instanceof JexlContext) {
127 | 11 |
                 jexlCtx = (JexlContext) ctx;
128 |  |
             } else {
129 | 0 |
                 throw new SCXMLExpressionException(ERR_CTX_TYPE);
130 |  |
             }
131 | 11 |
             Expression exp = null;
132 |  |
             try {
133 | 11 |
                 String evalExpr = inFct.matcher(expr).
134 |  |
                     replaceAll("_builtin.isMember(_ALL_STATES, ");
135 | 11 |
                 evalExpr = dataFct.matcher(evalExpr).
136 |  |
                     replaceFirst("_builtin.dataNode(_ALL_NAMESPACES, ");
137 | 11 |
                 evalExpr = dataFct.matcher(evalExpr).
138 |  |
                     replaceAll("_builtin.data(_ALL_NAMESPACES, ");
139 | 11 |
                 exp = ExpressionFactory.createExpression(evalExpr);
140 | 11 |
                 return (Node) exp.evaluate(getEffectiveContext(jexlCtx));
141 | 3 |
             } catch (Exception e) {
142 | 3 |
                 throw new SCXMLExpressionException(e);
143 |  |
             }
144 |  |
         }
145 |  |
146 |  |
         /**
147 |  |
          * Create a new child context.
148 |  |
          *
149 |  |
          * @param parent parent context
150 |  |
          * @return new child context
151 |  |
          * @see Evaluator#newContext(Context)
152 |  |
          */
153 |  |
         public Context newContext(final Context parent) {
154 | 137 |
             return new JexlContext(parent);
155 |  |
         }
156 |  |
157 |  |
         /**
158 |  |
          * Create a new context which is the summation of contexts from the
159 |  |
          * current state to document root, child has priority over parent
160 |  |
          * in scoping rules.
161 |  |
          *
162 |  |
          * @param nodeCtx The JexlContext for this state.
163 |  |
          * @return The effective JexlContext for the path leading up to
164 |  |
          *         document root.
165 |  |
          */
166 |  |
         private JexlContext getEffectiveContext(final JexlContext nodeCtx) {
167 | 123 |
             List contexts = new ArrayList();
168 |  |
             // trace path to root
169 | 123 |
             JexlContext currentCtx = nodeCtx;
170 | 434 |
             while (currentCtx != null) {
171 | 311 |
                 contexts.add(currentCtx);
172 | 311 |
                 currentCtx = (JexlContext) currentCtx.getParent();
173 |  |
             }
174 | 123 |
             Map vars = new HashMap();
175 |  |
             // summation of the contexts, parent first, child wins
176 | 434 |
             for (int i = contexts.size() - 1; i > -1; i--) {
177 | 311 |
                 vars.putAll(((JexlContext) contexts.get(i)).getVars());
178 |  |
             }
179 | 123 |
             return new JexlContext(vars);
180 |  |
         }
181 |  |
182 |  |
     }
183 |  |