1 /*
2 * Copyright 1999-2001,2004 The Apache Software Foundation.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.apache.commons.workflow.core;
18
19
20 import java.util.EmptyStackException;
21 import org.apache.commons.workflow.Block;
22 import org.apache.commons.workflow.BlockState;
23 import org.apache.commons.workflow.Context;
24 import org.apache.commons.workflow.Descriptor;
25 import org.apache.commons.workflow.Step;
26 import org.apache.commons.workflow.StepException;
27 import org.apache.commons.workflow.base.BaseBlock;
28
29
30 /**
31 * <p>Evaluate properties specified by the associated Descriptors, and
32 * execute the nested Steps if and only if <strong>ANY</strong> of them
33 * evaluate to a positive result. To avoid non-deterministic evaluation
34 * stack behavior, all of the specified Descriptors are always
35 * evaluated exactly once.</p>
36 *
37 * @version $Revision: 155475 $ $Date: 2005-02-26 13:31:11 +0000 (Sat, 26 Feb 2005) $
38 * @author Craig R. McClanahan
39 */
40
41 public class IfAnyStep extends IfStep {
42
43
44 // ----------------------------------------------------------= Constructors
45
46
47 /**
48 * Construct a default instance of this Step.
49 */
50 public IfAnyStep() {
51
52 super();
53
54 }
55
56
57 /**
58 * Construct an instance of this Step with the specified identifier.
59 *
60 * @param id Step identifier
61 */
62 public IfAnyStep(String id) {
63
64 this(id, null);
65
66 }
67
68
69 /**
70 * Construct a fully configured instance of this Step.
71 *
72 * @param id Step identifier of this step
73 * @param descriptor Initial descriptor to be added
74 */
75 public IfAnyStep(String id, Descriptor descriptor) {
76
77 super();
78 setId(id);
79 if (descriptor != null)
80 addDescriptor(descriptor);
81
82 }
83
84
85 // --------------------------------------------------------- Public Methods
86
87
88 /**
89 * Render a string representation of this Step.
90 */
91 public String toString() {
92
93 StringBuffer sb = new StringBuffer("<core:ifAny");
94 if (getId() != null) {
95 sb.append(" id=\"");
96 sb.append(getId());
97 sb.append("\"");
98 }
99 sb.append(">");
100 Descriptor descriptors[] = findDescriptors();
101 for (int i = 0; i < descriptors.length; i++)
102 sb.append(descriptors[i]);
103 Step steps[] = getSteps();
104 for (int i = 0; i < steps.length; i++)
105 sb.append(steps[i]);
106 sb.append("</core:ifAny>");
107 return (sb.toString());
108
109 }
110
111
112 // ------------------------------------------------------ Protected Methods
113
114
115 /**
116 * Evaluate the condition specified by the Descriptors associated with
117 * this Block, and return the resulting boolean value.
118 *
119 * @param context Context within which to evaluate the descriptors
120 */
121 protected boolean evaluate(Context context) {
122
123 boolean condition = false;
124 Descriptor descriptors[] = findDescriptors();
125 for (int i = 0; i < descriptors.length; i++) {
126 if (descriptors[i].positive(context))
127 condition = true;
128 }
129 return (condition);
130
131 }
132
133
134 }