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