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 015package org.apache.tapestry.enhance; 016 017import java.lang.reflect.Modifier; 018import java.util.Iterator; 019 020import org.apache.hivemind.ErrorLog; 021import org.apache.hivemind.Location; 022import org.apache.hivemind.service.ClassFabUtils; 023import org.apache.hivemind.service.MethodSignature; 024import org.apache.hivemind.util.Defense; 025import org.apache.tapestry.spec.IBeanSpecification; 026import 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 */ 034public 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}