Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
ExpressionManager |
|
| 1.0;1 |
1 | /* | |
2 | * $Id: ExpressionManager.java 19191 2010-08-25 21:05:23Z tcarlson $ | |
3 | * -------------------------------------------------------------------------------------- | |
4 | * Copyright (c) MuleSoft, Inc. All rights reserved. http://www.mulesoft.com | |
5 | * | |
6 | * The software in this package is published under the terms of the CPAL v1.0 | |
7 | * license, a copy of which has been included with this distribution in the | |
8 | * LICENSE.txt file. | |
9 | */ | |
10 | package org.mule.api.expression; | |
11 | ||
12 | import org.mule.api.MuleMessage; | |
13 | ||
14 | /** | |
15 | * Provides universal access for evaluating expressions embedded in Mule configurations, such as Xml, Java, | |
16 | * scripting and annotations. | |
17 | * <p/> | |
18 | * Users can register or unregister {@link ExpressionEvaluator} through this interface. | |
19 | */ | |
20 | public interface ExpressionManager | |
21 | { | |
22 | String DEFAULT_EXPRESSION_PREFIX = "#["; | |
23 | String DEFAULT_EXPRESSION_POSTFIX = "]"; | |
24 | ||
25 | public void registerEvaluator(ExpressionEvaluator evaluator); | |
26 | ||
27 | /** | |
28 | * Checks whether an evaluator is registered with the manager | |
29 | * | |
30 | * @param name the name of the expression evaluator | |
31 | * @return true if the evaluator is registered with the manager, false otherwise | |
32 | */ | |
33 | public boolean isEvaluatorRegistered(String name); | |
34 | ||
35 | /** | |
36 | * Removes the evaluator with the given name | |
37 | * | |
38 | * @param name the name of the evaluator to remove | |
39 | * @return the evaluator that was removed. This will be null if the evaluator was not registered | |
40 | */ | |
41 | public ExpressionEvaluator unregisterEvaluator(String name); | |
42 | ||
43 | /** | |
44 | * Evaluates the given expression. The expression should be a single expression definition with or without | |
45 | * enclosing braces. i.e. "mule:serviceName" and "#[mule:serviceName]" are both valid. For situations where | |
46 | * one or more expressions need to be parsed within a single text, the {@link #parse(String,org.mule.api.MuleMessage,boolean)} | |
47 | * method should be used since it will iterate through all expressions in a string. | |
48 | * | |
49 | * @param expression a single expression i.e. xpath://foo | |
50 | * @param message The current message being processed | |
51 | * @return the result of the evaluation | |
52 | * @throws ExpressionRuntimeException if the expression is invalid, or a null is found for the expression and | |
53 | * 'failIfNull is set to true. | |
54 | */ | |
55 | public Object evaluate(String expression, MuleMessage message) throws ExpressionRuntimeException; | |
56 | ||
57 | /** | |
58 | * Evaluates the given expression. The expression should be a single expression definition with or without | |
59 | * enclosing braces. i.e. "mule:serviceName" and "#[mule:serviceName]" are both valid. For situations where | |
60 | * one or more expressions need to be parsed within a single text, the {@link #parse(String,org.mule.api.MuleMessage,boolean)} | |
61 | * method should be used since it will iterate through all expressions in a string. | |
62 | * | |
63 | * @param expression a single expression i.e. xpath://foo | |
64 | * @param message The current message being processed | |
65 | * @param failIfNull determines if an exception should be thrown if expression could not be evaluated or returns | |
66 | * null. @return the result of the evaluation | |
67 | * @return the parsered expression string | |
68 | * @throws ExpressionRuntimeException if the expression is invalid, or a null is found for the expression and | |
69 | * 'failIfNull is set to true. | |
70 | */ | |
71 | public Object evaluate(String expression, MuleMessage message, boolean failIfNull) throws ExpressionRuntimeException; | |
72 | ||
73 | /** | |
74 | * Evaluates the given expression. The expression should be a single expression definition with or without | |
75 | * enclosing braces. i.e. "mule:serviceName" and "#[mule:serviceName]" are both valid. For situations where | |
76 | * one or more expressions need to be parsed within a single text, the {@link #parse(String,org.mule.api.MuleMessage,boolean)} | |
77 | * method should be used since it will iterate through all expressions in a string. | |
78 | * | |
79 | * @param expression one or more expressions ebedded in a literal string i.e. "Value is #[xpath://foo] other value is #[header:foo]." | |
80 | * @param evaluator the evaluator to use when executing the expression | |
81 | * @param message The current message bing processed | |
82 | * @param failIfNull determines if an exception should be thrown if expression could not be evaluated or returns | |
83 | * null. @return the result of the evaluation | |
84 | * @return the parsered expression string | |
85 | * @throws ExpressionRuntimeException if the expression is invalid, or a null is found for the expression and | |
86 | * 'failIfNull is set to true. | |
87 | */ | |
88 | public Object evaluate(String expression, String evaluator, MuleMessage message, boolean failIfNull) throws ExpressionRuntimeException; | |
89 | ||
90 | ||
91 | /** | |
92 | * Evaluates expressions in a given string. This method will iterate through each expression and evaluate it. If | |
93 | * a user needs to evaluate a single expression they can use {@link #evaluate(String,org.mule.api.MuleMessage,boolean)}. | |
94 | * | |
95 | * @param expression one or more expressions ebedded in a literal string i.e. "Value is #[xpath://foo] other value is #[header:foo]." | |
96 | * @param message The current message being processed | |
97 | * @return the result of the evaluation | |
98 | * @throws org.mule.api.expression.ExpressionRuntimeException | |
99 | * if the expression is invalid, or a null is found for the expression and | |
100 | * 'failIfNull is set to true. | |
101 | */ | |
102 | public String parse(String expression, MuleMessage message) throws ExpressionRuntimeException; | |
103 | ||
104 | /** | |
105 | * Evaluates expressions in a given string. This method will iterate through each expression and evaluate it. If | |
106 | * a user needs to evaluate a single expression they can use {@link #evaluate(String,org.mule.api.MuleMessage,boolean)}. | |
107 | * | |
108 | * @param expression one or more expressions ebedded in a literal string i.e. "Value is #[xpath://foo] other value is #[header:foo]." | |
109 | * @param message The current message being processed | |
110 | * @param failIfNull determines if an exception should be thrown if expression could not be evaluated or returns | |
111 | * null. @return the result of the evaluation | |
112 | * @return the parsered expression string | |
113 | * @throws ExpressionRuntimeException if the expression is invalid, or a null is found for the expression and | |
114 | * 'failIfNull is set to true. | |
115 | */ | |
116 | public String parse(final String expression, final MuleMessage message, final boolean failIfNull) throws ExpressionRuntimeException; | |
117 | ||
118 | /** | |
119 | * Clears all registered evaluators from the manager. | |
120 | */ | |
121 | public void clearEvaluators(); | |
122 | ||
123 | /** | |
124 | * Determines if the expression is valid or not. This method will validate a single expression or | |
125 | * expressions embedded in a string. the expression must be well formed i.e. #[bean:user] | |
126 | * | |
127 | * @param expression the expression to validate | |
128 | * @return true if the expression evaluator is recognised | |
129 | */ | |
130 | public boolean isValidExpression(String expression); | |
131 | ||
132 | /** | |
133 | * Determines if the expression is valid or not. This method will validate a single expression or | |
134 | * expressions embedded in a string. the expression must be well formed i.e. #[bean:user] | |
135 | * | |
136 | * @param expression the expression to validate | |
137 | * @throws InvalidExpressionException if the expression is invalid, including information about the position and fault | |
138 | * | |
139 | * @since 3.0 | |
140 | */ | |
141 | public void validateExpression(String expression) throws InvalidExpressionException; | |
142 | ||
143 | /** | |
144 | * Determines if the string is an expression. This method will validate that the string contains either the expression | |
145 | * prefix (malformed) or a full expression. This isn't full proof but catches most error cases | |
146 | * | |
147 | * @param string is this string an expression string | |
148 | * @return true if the string contains an expression | |
149 | * | |
150 | * @since 3.0 | |
151 | */ | |
152 | public boolean isExpression(String string); | |
153 | ||
154 | } |