/* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.camunda.bpm.engine.impl.task.listener;
import static org.camunda.bpm.engine.impl.util.ClassDelegateUtil.applyFieldDeclaration;
import java.util.List;
import org.camunda.bpm.engine.ProcessEngineException;
import org.camunda.bpm.engine.delegate.DelegateTask;
import org.camunda.bpm.engine.delegate.Expression;
import org.camunda.bpm.engine.delegate.TaskListener;
import org.camunda.bpm.engine.delegate.VariableScope;
import org.camunda.bpm.engine.impl.bpmn.parser.FieldDeclaration;
import org.camunda.bpm.engine.impl.context.Context;
import org.camunda.bpm.engine.impl.task.delegate.TaskListenerInvocation;
/**
* @author Joram Barrez
*/
public class DelegateExpressionTaskListener implements TaskListener {
protected Expression expression;
private final List<FieldDeclaration> fieldDeclarations;
public DelegateExpressionTaskListener(Expression expression, List<FieldDeclaration> fieldDeclarations) {
this.expression = expression;
this.fieldDeclarations = fieldDeclarations;
}
public void notify(DelegateTask delegateTask) {
// Note: we can't cache the result of the expression, because the
// execution can change: eg. delegateExpression='${mySpringBeanFactory.randomSpringBean()}'
VariableScope variableScope = delegateTask.getExecution();
if (variableScope == null) {
variableScope = delegateTask.getCaseExecution();
}
Object delegate = expression.getValue(variableScope);
applyFieldDeclaration(fieldDeclarations, delegate);
if (delegate instanceof TaskListener) {
try {
Context.getProcessEngineConfiguration()
.getDelegateInterceptor()
.handleInvocation(new TaskListenerInvocation((TaskListener)delegate, delegateTask));
}catch (Exception e) {
throw new ProcessEngineException("Exception while invoking TaskListener: "+e.getMessage(), e);
}
} else {
throw new ProcessEngineException("Delegate expression " + expression
+ " did not resolve to an implementation of " + TaskListener.class );
}
}
/**
* returns the expression text for this task listener. Comes in handy if you want to
* check which listeners you already have.
*/
public String getExpressionText() {
return expression.getExpressionText();
}
public List<FieldDeclaration> getFieldDeclarations() {
return fieldDeclarations;
}
}