##### 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 |  |
      *
3 |  |
      *   Copyright 2006 The Apache Software Foundation.
4 |  |
      *
5 |  |
      *  Licensed under the Apache License, Version 2.0 (the "License");
6 |  |
      *  you may not use this file except in compliance with the License.
7 |  |
      *  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 |  |
      */
18 |  |
     package org.apache.commons.scxml.env.jexl;
19 |  |
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 {
39 |  |
40 |  |
         /** Error message if evaluation context is not a JexlContext. */
41 |  |
         private static final String ERR_CTX_TYPE = "Error evaluating JEXL "
42 |  |
             + "expression, Context must be a org.apache.commons.jexl.JexlContext";
43 |  |
44 |  |
         /** Pattern for recognizing the SCXML In() special predicate. */
45 | 4 |
         private static Pattern inFct = Pattern.compile("In\\(");
46 |  |
         /** Pattern for recognizing the Commons SCXML Data() builtin function. */
47 | 4 |
         private static Pattern dataFct = Pattern.compile("Data\\(");
48 |  |
49 |  |
         /** Constructor. */
50 |  |
         public JexlEvaluator() {
51 | 28 |
             super();
52 | 28 |
         }
53 |  |
54 |  |
         /**
55 |  |
          * Evaluate an expression.
56 |  |
          *
57 |  |
          * @param ctx variable context
58 |  |
          * @param expr expression
59 |  |
          * @return a result of the evaluation
60 |  |
          * @throws SCXMLExpressionException For a malformed expression
61 |  |
          * @see Evaluator#eval(Context, String)
62 |  |
          */
63 |  |
         public Object eval(final Context ctx, final String expr)
64 |  |
         throws SCXMLExpressionException {
65 | 35 |
             if (expr == null) {
66 | 0 |
                 return null;
67 |  |
             }
68 | 35 |
             JexlContext jexlCtx = null;
69 | 35 |
             if (ctx instanceof JexlContext) {
70 | 35 |
                 jexlCtx = (JexlContext) ctx;
71 |  |
             } else {
72 | 0 |
                 throw new SCXMLExpressionException(ERR_CTX_TYPE);
73 |  |
             }
74 | 35 |
             Expression exp = null;
75 |  |
             try {
76 | 35 |
                 String evalExpr = inFct.matcher(expr).
77 |  |
                     replaceAll("_builtin.isMember(_ALL_STATES, ");
78 | 35 |
                 evalExpr = dataFct.matcher(evalExpr).
79 |  |
                     replaceAll("_builtin.data(");
80 | 35 |
                 exp = ExpressionFactory.createExpression(evalExpr);
81 | 35 |
                 return exp.evaluate(getEffectiveContext(jexlCtx));
82 | 0 |
             } catch (Exception e) {
83 | 0 |
                 throw new SCXMLExpressionException(e);
84 |  |
             }
85 |  |
         }
86 |  |
87 |  |
         /**
88 |  |
          * @see Evaluator#evalCond(Context, String)
89 |  |
          */
90 |  |
         public Boolean evalCond(final Context ctx, final String expr)
91 |  |
         throws SCXMLExpressionException {
92 | 40 |
             if (expr == null) {
93 | 0 |
                 return null;
94 |  |
             }
95 | 40 |
             JexlContext jexlCtx = null;
96 | 40 |
             if (ctx instanceof JexlContext) {
97 | 40 |
                 jexlCtx = (JexlContext) ctx;
98 |  |
             } else {
99 | 0 |
                 throw new SCXMLExpressionException(ERR_CTX_TYPE);
100 |  |
             }
101 | 40 |
             Expression exp = null;
102 |  |
             try {
103 | 40 |
                 String evalExpr = inFct.matcher(expr).
104 |  |
                     replaceAll("_builtin.isMember(_ALL_STATES, ");
105 | 40 |
                 evalExpr = dataFct.matcher(evalExpr).
106 |  |
                     replaceAll("_builtin.data(");
107 | 40 |
                 exp = ExpressionFactory.createExpression(evalExpr);
108 | 40 |
                 return (Boolean) exp.evaluate(getEffectiveContext(jexlCtx));
109 | 0 |
             } catch (Exception e) {
110 | 0 |
                 throw new SCXMLExpressionException(e);
111 |  |
             }
112 |  |
         }
113 |  |
114 |  |
         /**
115 |  |
          * @see Evaluator#evalLocation(Context, String)
116 |  |
          */
117 |  |
         public Node evalLocation(final Context ctx, final String expr)
118 |  |
         throws SCXMLExpressionException {
119 | 9 |
             if (expr == null) {
120 | 0 |
                 return null;
121 |  |
             }
122 | 9 |
             JexlContext jexlCtx = null;
123 | 9 |
             if (ctx instanceof JexlContext) {
124 | 9 |
                 jexlCtx = (JexlContext) ctx;
125 |  |
             } else {
126 | 0 |
                 throw new SCXMLExpressionException(ERR_CTX_TYPE);
127 |  |
             }
128 | 9 |
             Expression exp = null;
129 |  |
             try {
130 | 9 |
                 String evalExpr = inFct.matcher(expr).
131 |  |
                     replaceAll("_builtin.isMember(_ALL_STATES, ");
132 | 9 |
                 evalExpr = dataFct.matcher(evalExpr).
133 |  |
                     replaceFirst("_builtin.dataNode(");
134 | 9 |
                 evalExpr = dataFct.matcher(evalExpr).
135 |  |
                     replaceAll("_builtin.data(");
136 | 9 |
                 exp = ExpressionFactory.createExpression(evalExpr);
137 | 9 |
                 return (Node) exp.evaluate(getEffectiveContext(jexlCtx));
138 | 2 |
             } catch (Exception e) {
139 | 2 |
                 throw new SCXMLExpressionException(e);
140 |  |
             }
141 |  |
         }
142 |  |
143 |  |
         /**
144 |  |
          * Create a new child context.
145 |  |
          *
146 |  |
          * @param parent parent context
147 |  |
          * @return new child context
148 |  |
          * @see Evaluator#newContext(Context)
149 |  |
          */
150 |  |
         public Context newContext(final Context parent) {
151 | 106 |
             return new JexlContext(parent);
152 |  |
         }
153 |  |
154 |  |
         /**
155 |  |
          * Create a new context which is the summation of contexts from the
156 |  |
          * current state to document root, child has priority over parent
157 |  |
          * in scoping rules.
158 |  |
          *
159 |  |
          * @param nodeCtx The JexlContext for this state.
160 |  |
          * @return The effective JexlContext for the path leading up to
161 |  |
          *         document root.
162 |  |
          */
163 |  |
         private JexlContext getEffectiveContext(final JexlContext nodeCtx) {
164 | 84 |
             List contexts = new ArrayList();
165 |  |
             // trace path to root
166 | 84 |
             JexlContext currentCtx = nodeCtx;
167 | 317 |
             while (currentCtx != null) {
168 | 233 |
                 contexts.add(currentCtx);
169 | 233 |
                 currentCtx = (JexlContext) currentCtx.getParent();
170 |  |
             }
171 | 84 |
             Map vars = new HashMap();
172 |  |
             // summation of the contexts, parent first, child wins
173 | 317 |
             for (int i = contexts.size() - 1; i > -1; i--) {
174 | 233 |
                 vars.putAll(((JexlContext) contexts.get(i)).getVars());
175 |  |
             }
176 | 84 |
             return new JexlContext(vars);
177 |  |
         }
178 |  |
179 |  |
     }
180 |  |