Coverage Report - org.apache.tapestry.annotations.MetaAnnotationWorker
 
Classes in this File Line Coverage Branch Coverage Complexity
MetaAnnotationWorker
0%
0/26
0%
0/10
3.333
 
 1  
 // Copyright 2005 The Apache Software Foundation
 2  
 //
 3  
 // Licensed under the Apache License, Version 2.0 (the "License");
 4  
 // you may not use this file except in compliance with the License.
 5  
 // You may obtain a copy of the License at
 6  
 //
 7  
 //     http://www.apache.org/licenses/LICENSE-2.0
 8  
 //
 9  
 // Unless required by applicable law or agreed to in writing, software
 10  
 // distributed under the License is distributed on an "AS IS" BASIS,
 11  
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 12  
 // See the License for the specific language governing permissions and
 13  
 // limitations under the License.
 14  
 
 15  
 package org.apache.tapestry.annotations;
 16  
 
 17  
 import java.util.ArrayList;
 18  
 import java.util.Collections;
 19  
 import java.util.List;
 20  
 
 21  
 import org.apache.hivemind.ApplicationRuntimeException;
 22  
 import org.apache.hivemind.Location;
 23  
 import org.apache.tapestry.enhance.EnhancementOperation;
 24  
 import org.apache.tapestry.spec.IComponentSpecification;
 25  
 
 26  
 /**
 27  
  * Recognizes the {@link org.apache.tapestry.annotations.Meta} annotation, and converts it into
 28  
  * properties on the specification. It is desirable to have meta data in base classes be "merged"
 29  
  * with meta data from sub classes, with the sub classes overriding any conflicting elements from
 30  
  * the base class. What we do is work our way up the inheritance tree to java.lang.Object and work
 31  
  * with each Meta annotation we find.
 32  
  * 
 33  
  * @author Howard M. Lewis Ship
 34  
  * @since 4.0
 35  
  */
 36  0
 public class MetaAnnotationWorker implements ClassAnnotationEnhancementWorker
 37  
 {
 38  
 
 39  
     public void performEnhancement(EnhancementOperation op, IComponentSpecification spec,
 40  
             Class baseClass, Location location)
 41  
     {
 42  0
         List<Meta> metas = assembleMetas(baseClass);
 43  
 
 44  0
         for (Meta meta : metas)
 45  0
             applyPropertiesFromMeta(meta, spec, location);
 46  0
     }
 47  
 
 48  
     private List<Meta> assembleMetas(Class baseClass)
 49  
     {
 50  0
         Class searchClass = baseClass;
 51  0
         List<Meta> result = new ArrayList<Meta>();
 52  0
         Meta lastMeta = null;
 53  
 
 54  
         while (true)
 55  
         {
 56  0
             Meta meta = (Meta) searchClass.getAnnotation(Meta.class);
 57  
 
 58  
             // When reach a class that doesn't define or inherit a @Meta, we're done
 59  0
             if (meta == null)
 60  0
                 break;
 61  
 
 62  
             // Cheap approach, based on annotation inheritance, for determining
 63  
             // whether a meta is already in the result list
 64  
 
 65  0
             if (meta != lastMeta)
 66  0
                 result.add(meta);
 67  
 
 68  0
             searchClass = searchClass.getSuperclass();
 69  0
         }
 70  
 
 71  0
         Collections.reverse(result);
 72  
 
 73  0
         return result;
 74  
     }
 75  
 
 76  
     private void applyPropertiesFromMeta(Meta meta, IComponentSpecification spec, Location location)
 77  
     {
 78  0
         String[] pairs = meta.value();
 79  
 
 80  0
         for (String pair : pairs)
 81  
         {
 82  0
             int equalx = pair.indexOf('=');
 83  
 
 84  
             // The only big problem is that the location will be the location of the @Meta in
 85  
             // the subclass, even if the @Meta with a problem is from a base class.
 86  
 
 87  0
             if (equalx < 0)
 88  0
                 throw new ApplicationRuntimeException(AnnotationMessages.missingEqualsInMeta(pair),
 89  
                         location, null);
 90  
 
 91  0
             String key = pair.substring(0, equalx);
 92  0
             String value = pair.substring(equalx + 1);
 93  
 
 94  0
             spec.setProperty(key, value);
 95  
         }
 96  0
     }
 97  
 }