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 org.apache.hivemind.ErrorLog;
018    import org.apache.hivemind.util.Defense;
019    import org.apache.tapestry.spec.IComponentSpecification;
020    
021    /**
022     * Injects the component's specification as the
023     * {@link org.apache.tapestry.IComponent#getSpecification() specification}property.
024     * 
025     * @author Howard M. Lewis Ship
026     * @since 4.0
027     */
028    public class InjectSpecificationWorker implements EnhancementWorker
029    {
030        public static final String SPECIFICATION_PROPERTY_NAME = "specification";
031    
032        private ErrorLog _errorLog;
033    
034        public void performEnhancement(EnhancementOperation op, IComponentSpecification spec)
035        {
036            try
037            {
038                injectSpecification(op, spec);
039            }
040            catch (Exception ex)
041            {
042                _errorLog.error(EnhanceMessages.errorAddingProperty(SPECIFICATION_PROPERTY_NAME, op
043                        .getBaseClass(), ex), spec.getLocation(), ex);
044            }
045        }
046    
047        public void injectSpecification(EnhancementOperation op, IComponentSpecification spec)
048        {
049            Defense.notNull(op, "op");
050            Defense.notNull(spec, "spec");
051    
052            op.claimReadonlyProperty(SPECIFICATION_PROPERTY_NAME);
053    
054            String fieldName = op.addInjectedField(
055                    "_$" + SPECIFICATION_PROPERTY_NAME,
056                    IComponentSpecification.class,
057                    spec);
058    
059            EnhanceUtils.createSimpleAccessor(
060                    op,
061                    fieldName,
062                    SPECIFICATION_PROPERTY_NAME,
063                    IComponentSpecification.class,
064                    spec.getLocation());
065        }
066    
067        public void setErrorLog(ErrorLog errorLog)
068        {
069            _errorLog = errorLog;
070        }
071    }