001    // Copyright 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.enhance;
016    
017    import java.lang.reflect.Modifier;
018    import java.util.Iterator;
019    
020    import org.apache.hivemind.ErrorLog;
021    import org.apache.hivemind.Location;
022    import org.apache.hivemind.service.ClassFabUtils;
023    import org.apache.hivemind.service.MethodSignature;
024    import org.apache.hivemind.util.Defense;
025    import org.apache.tapestry.spec.IBeanSpecification;
026    import org.apache.tapestry.spec.IComponentSpecification;
027    
028    /**
029     * Injects a property that will dynamically access a managed bean.
030     * 
031     * @author Howard M. Lewis Ship
032     * @since 4.0
033     */
034    public class InjectBeanWorker implements EnhancementWorker
035    {
036        private ErrorLog _errorLog;
037    
038        public void performEnhancement(EnhancementOperation op, IComponentSpecification spec)
039        {
040            Iterator i = spec.getBeanNames().iterator();
041    
042            while (i.hasNext())
043            {
044                String name = (String) i.next();
045    
046                IBeanSpecification bs = spec.getBeanSpecification(name);
047    
048                String propertyName = bs.getPropertyName();
049                if (propertyName != null)
050                {
051                    try
052                    {
053                        injectBean(op, name, propertyName, bs.getLocation());
054                    }
055                    catch (Exception ex)
056                    {
057                        _errorLog.error(EnhanceMessages.errorAddingProperty(propertyName, op
058                                .getBaseClass(), ex), bs.getLocation(), ex);
059                    }
060                }
061            }
062        }
063    
064        public void injectBean(EnhancementOperation op, String beanName, String propertyName,
065                Location location)
066        {
067            Defense.notNull(op, "op");
068            Defense.notNull(beanName, "beanName");
069            Defense.notNull(propertyName, "propertyName");
070    
071            op.claimReadonlyProperty(propertyName);
072    
073            Class propertyType = EnhanceUtils.extractPropertyType(op, propertyName, null);
074    
075            String methodName = op.getAccessorMethodName(propertyName);
076    
077            MethodSignature sig = new MethodSignature(propertyType, methodName, null, null);
078    
079            // i.e.
080            // return (foo.bar.Baz) getBeans().getBean("baz");
081    
082            op.addMethod(Modifier.PUBLIC, sig, "return ("
083                    + ClassFabUtils.getJavaClassName(propertyType) + ") getBeans().getBean(\""
084                    + beanName + "\");", location);
085        }
086    
087        public void setErrorLog(ErrorLog errorLog)
088        {
089            _errorLog = errorLog;
090        }
091    }