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.util.Iterator; 018 019 import org.apache.hivemind.ApplicationRuntimeException; 020 import org.apache.hivemind.ErrorLog; 021 import org.apache.hivemind.Location; 022 import org.apache.hivemind.util.Defense; 023 import org.apache.tapestry.IAsset; 024 import org.apache.tapestry.IComponent; 025 import org.apache.tapestry.spec.IAssetSpecification; 026 import org.apache.tapestry.spec.IComponentSpecification; 027 028 /** 029 * Injects assets as component properties. 030 * 031 * @author Howard M. Lewis Ship 032 * @since 4.0 033 */ 034 public class InjectAssetWorker implements EnhancementWorker 035 { 036 private ErrorLog _errorLog; 037 038 public void performEnhancement(EnhancementOperation op, IComponentSpecification spec) 039 { 040 Iterator i = spec.getAssetNames().iterator(); 041 while (i.hasNext()) 042 { 043 String name = (String) i.next(); 044 045 IAssetSpecification as = spec.getAsset(name); 046 047 String propertyName = as.getPropertyName(); 048 049 if (propertyName != null) 050 { 051 try 052 { 053 injectAsset(op, name, propertyName, as.getLocation()); 054 } 055 catch (Exception ex) 056 { 057 _errorLog.error(EnhanceMessages.errorAddingProperty(propertyName, op 058 .getBaseClass(), ex), as.getLocation(), ex); 059 } 060 } 061 } 062 } 063 064 public void injectAsset(EnhancementOperation op, String assetName, String propertyName, Location location) 065 { 066 Defense.notNull(op, "op"); 067 Defense.notNull(assetName, "assetName"); 068 Defense.notNull(propertyName, "propertyName"); 069 070 Class propertyType = EnhanceUtils.extractPropertyType(op, propertyName, null); 071 072 op.claimReadonlyProperty(propertyName); 073 074 if (!propertyType.isAssignableFrom(IAsset.class)) 075 throw new ApplicationRuntimeException(EnhanceMessages.incompatiblePropertyType( 076 propertyName, 077 propertyType, 078 IAsset.class)); 079 080 String fieldName = "_$" + propertyName; 081 082 op.addField(fieldName, propertyType); 083 084 EnhanceUtils.createSimpleAccessor(op, fieldName, propertyName, propertyType, location); 085 086 // i.e. _$fred = getAsset("barney"); 087 088 String code = fieldName + " = getAsset(\"" + assetName + "\");"; 089 090 op.extendMethodImplementation(IComponent.class, EnhanceUtils.FINISH_LOAD_SIGNATURE, code); 091 } 092 093 public void setErrorLog(ErrorLog errorLog) 094 { 095 _errorLog = errorLog; 096 } 097 }