| // Copyright 2004, 2005 The Apache Software Foundation |
| // |
| // 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.apache.tapestry.enhance; |
| |
| import org.apache.hivemind.ErrorLog; |
| import org.apache.hivemind.Location; |
| import org.apache.hivemind.service.MethodSignature; |
| import org.apache.tapestry.IComponent; |
| import org.apache.tapestry.event.PageDetachListener; |
| import org.apache.tapestry.spec.IComponentSpecification; |
| |
| import java.lang.reflect.Modifier; |
| import java.util.Iterator; |
| |
| |
| /** |
| * Enhances the {@link org.apache.tapestry.IComponent#getClientId()} property. |
| */ |
| public class ClientIdPropertyWorker implements EnhancementWorker |
| { |
| private static final String PROPERTY_NAME = "clientId"; |
| |
| private ErrorLog _errorLog; |
| |
| public void performEnhancement(EnhancementOperation op, IComponentSpecification spec) |
| { |
| Location location = spec.getLocation(); |
| |
| Iterator i = op.findUnclaimedAbstractProperties().iterator(); |
| |
| while (i.hasNext()) |
| { |
| String name = (String) i.next(); |
| |
| if (name.equals(PROPERTY_NAME)) { |
| |
| try |
| { |
| createProperty(op, name, location); |
| } |
| catch (Exception ex) |
| { |
| _errorLog.error( |
| EnhanceMessages.errorAddingProperty(name, op.getBaseClass(), ex), |
| location, |
| ex); |
| } |
| |
| break; |
| } |
| } |
| } |
| |
| private void createProperty(EnhancementOperation op, String name, Location location) |
| { |
| // This won't be null because its always for existing properties. |
| |
| Class propertyType = op.getPropertyType(name); |
| |
| String fieldName = "_$" + name; |
| String defaultFieldName = fieldName + "$defaultValue"; |
| |
| op.addField(fieldName, propertyType); |
| op.addField(defaultFieldName, propertyType); |
| |
| String methodName = op.getAccessorMethodName(name); |
| |
| // Build special getter logic |
| // if the client id is null "peek" at the next possible unique id |
| |
| StringBuffer str = new StringBuffer(); |
| |
| str.append(" if(").append(fieldName).append(" == null){") |
| .append(" if (getPage() == null) { return null; }") |
| .append(" String tempId = getSpecifiedId();") |
| .append(" if (tempId == null) { return null; }") |
| .append(" return getPage().getRequestCycle().peekUniqueId(org.apache.tapestry.TapestryUtils#convertTapestryIdToNMToken(tempId));") |
| .append("} else { "); |
| |
| // else return the existing clientId |
| |
| str.append("return ").append(fieldName).append(";"); |
| str.append("}"); |
| |
| op.addMethod( |
| Modifier.PUBLIC, |
| new MethodSignature(propertyType, methodName, null, null), |
| str.toString(), |
| location); |
| |
| EnhanceUtils.createSimpleMutator(op, fieldName, name, propertyType, location); |
| |
| // Copy the real attribute into the default attribute inside finish load |
| // (allowing a default value to be set inside finishLoad()). |
| |
| op.extendMethodImplementation( |
| IComponent.class, |
| EnhanceUtils.FINISH_LOAD_SIGNATURE, |
| defaultFieldName + " = " + fieldName + ";"); |
| |
| // On page detach, restore the attribute to its default value. |
| |
| op.extendMethodImplementation( |
| PageDetachListener.class, |
| EnhanceUtils.PAGE_DETACHED_SIGNATURE, |
| fieldName + " = " + defaultFieldName + ";"); |
| |
| // This is not all that necessary, but is proper. |
| |
| op.claimProperty(name); |
| } |
| |
| public void setErrorLog(ErrorLog errorLog) |
| { |
| _errorLog = errorLog; |
| } |
| } |