01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one or more
03: * contributor license agreements. See the NOTICE file distributed with
04: * this work for additional information regarding copyright ownership.
05: * The ASF licenses this file to You under the Apache License, Version 2.0
06: * (the "License"); you may not use this file except in compliance with
07: * the License. You may obtain a copy of the License at
08: *
09: * 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:
19: /* $Id: Condition.java 473861 2006-11-12 03:51:14Z gregor $ */
20:
21: package org.apache.lenya.workflow;
22:
23: /**
24: * <p>A condition can prevent a transition from firing,
25: * based on the current situation. Examples:</p>
26: * <ul>
27: * <li>Does the current user have a certain role on the current URL?</li>
28: * <li>Does a certain state variable have a certain value (e.g., is the document published)? (BooleanVariableCondition)<li>
29: * <li>Is the sun shining? (e.g., if the weather report may only be published on sunny days)</li>
30: * </ul>
31: */
32: public interface Condition {
33:
34: /**
35: * Returns if the condition is complied in a certain situation.
36: * @param workflow The workflow to use.
37: * @param workflowable The workflowable to check the condition on.
38: * @return if the condition is complied.
39: * @throws WorkflowException when the expression could not be evaluated.
40: */
41: boolean isComplied(Workflow workflow, Workflowable workflowable)
42: throws WorkflowException;
43:
44: /** Sets the expression for this condition.
45: * @param expression The expression.
46: * @throws WorkflowException when the expression is not valid.
47: */
48: void setExpression(String expression) throws WorkflowException;
49: }
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