Coverage Report - org.apache.tapestry.enhance.EnhancementOperation
 
Classes in this File Line Coverage Branch Coverage Complexity
EnhancementOperation
N/A
N/A
1
 
 1  
 // Copyright 2004, 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.enhance;
 16  
 
 17  
 import org.apache.hivemind.Location;
 18  
 import org.apache.hivemind.service.MethodSignature;
 19  
 import org.apache.tapestry.spec.IComponentSpecification;
 20  
 
 21  
 import java.util.List;
 22  
 
 23  
 /**
 24  
  * A process object representing enhancements to a component class. The
 25  
  * operation is passed to {@link org.apache.tapestry.enhance.EnhancementWorker}objects
 26  
  * that perform enhancements.
 27  
  * 
 28  
  * @author Howard M. Lewis Ship
 29  
  * @since 4.0
 30  
  */
 31  
 public interface EnhancementOperation
 32  
 {
 33  
 
 34  
     /**
 35  
      * Claims a property. Most enhancements are concerned with adding
 36  
      * properties. Some enhancement workers exist to fill in defaults, and they
 37  
      * need to know what properties have already been spoken for by eariler
 38  
      * enhancement works.
 39  
      * 
 40  
      * @throws org.apache.hivemind.ApplicationRuntimeException
 41  
      *             if the property was previously claimed
 42  
      */
 43  
 
 44  
     void claimProperty(String propertyName);
 45  
 
 46  
     /**
 47  
      * Claims a property as read-only. This will check to see if the property
 48  
      * has an abstract setter method.
 49  
      * 
 50  
      * @throws org.apache.hivemind.ApplicationRuntimeException
 51  
      *             if the property was previously claimed, or if the property
 52  
      *             includes an accessor method.
 53  
      */
 54  
 
 55  
     void claimReadonlyProperty(String propertyName);
 56  
     
 57  
     /**
 58  
      * Checks to see if the specified property can be claimed as read only. 
 59  
      * 
 60  
      * @param propertyName
 61  
      *          The property to check.
 62  
      * 
 63  
      * @return True, if no setter method has been created for the specified property and
 64  
      *          the property hasn't been claimed by someone else.
 65  
      */
 66  
     boolean canClaimAsReadOnlyProperty(String propertyName);
 67  
     
 68  
     /**
 69  
      * Returns a list of the names of existing properties that are not claimed
 70  
      * and which have abstract accessor methods.
 71  
      */
 72  
 
 73  
     List findUnclaimedAbstractProperties();
 74  
 
 75  
     /**
 76  
      * Adds a field to the enhanced class; the field will be private and use the
 77  
      * provided name and type.
 78  
      */
 79  
 
 80  
     void addField(String name, Class type);
 81  
 
 82  
     /**
 83  
      * Adds a field containing an initial value, which is injected into the
 84  
      * class via its fabricated constructor. This method may be called multiple
 85  
      * times with the same value and will return the same variable name (an
 86  
      * identity map is kept internally).
 87  
      * 
 88  
      * @param fieldName
 89  
      *            The default name for the field, used if a new field (and
 90  
      *            contructor argument) is being created. Only used if a field
 91  
      *            for the value doesn't exist.
 92  
      * @param fieldType
 93  
      *            The type of the field to be created.
 94  
      * @param value
 95  
      *            the value to be referenced, which may not be null
 96  
      * @return the name of the field containing the value. This may or may not
 97  
      *         match fieldName. The provided fieldName may be modified to
 98  
      *         prevent naming conflicts.
 99  
      */
 100  
 
 101  
     String addInjectedField(String fieldName, Class fieldType, Object value);
 102  
 
 103  
     /**
 104  
      * Converts a type name (an object class name, a primtive name, or an array)
 105  
      * into the corresponding Class object.
 106  
      */
 107  
 
 108  
     Class convertTypeName(String type);
 109  
 
 110  
     /**
 111  
      * Confirms that the named property either doesn't exist (in the component
 112  
      * base class), or that the type of the property exactly matches the
 113  
      * indicated type.
 114  
      */
 115  
 
 116  
     void validateProperty(String name, Class expectedType);
 117  
 
 118  
     /**
 119  
      * Returns the name of the accessor method for the given property (if it
 120  
      * exists in the component base class), or fabricates a new name if it does
 121  
      * not.
 122  
      *
 123  
      * @param propertyName
 124  
      *          The property to get an accessor method name of.
 125  
      *
 126  
      * @return The existing/future name of an appropriate accessor method for the property.
 127  
      */
 128  
 
 129  
     String getAccessorMethodName(String propertyName);
 130  
 
 131  
     /**
 132  
      * Adds a method to the enhanced class.
 133  
      * 
 134  
      * @param modifier
 135  
      *            as defined by {@link java.lang.reflect.Modifier}, typically
 136  
      *            {@link java.lang.reflect.Modifier#PUBLIC}
 137  
      * @param sig
 138  
      *            the method signature (defining name, return type, etc.)
 139  
      * @param methodBody
 140  
      *            a Javassist code snippet for the method body
 141  
      * @param location
 142  
      *            a location used to identify "why" the method was added; the
 143  
      *            location may later be used to describe conflicts. May not be
 144  
      *            null.
 145  
      */
 146  
     void addMethod(int modifier, MethodSignature sig, String methodBody, Location location);
 147  
 
 148  
     /**
 149  
      * Returns the base component class, as defined in the specification (or
 150  
      * defaulted). An enhaced subclass of the component class will usually be
 151  
      * created.
 152  
      *
 153  
      * @return The class this enhancement operation is operating on.
 154  
      */
 155  
     Class getBaseClass();
 156  
 
 157  
     /**
 158  
      * Returns a reference to a particular class. This will, effectively, by the
 159  
      * name of a private field.
 160  
      *
 161  
      * @param clazz The class to get a string equivalent reference of.
 162  
      *
 163  
      * @return The enhancement (javassist) compatiable string version of the specified class.
 164  
      */
 165  
 
 166  
     String getClassReference(Class clazz);
 167  
 
 168  
     /**
 169  
      * Returns the type of an existing property of the base component class. If
 170  
      * the property does not exist, then returns null.
 171  
      *
 172  
      * @param name
 173  
      *          The property name.
 174  
      * 
 175  
      * @return The property type, or null if it doesn't exist.
 176  
      */
 177  
 
 178  
     Class getPropertyType(String name);
 179  
 
 180  
     /**
 181  
      * Allows for a kind of distributed construction of a particular method,
 182  
      * within a particular interface. Code can be appended to the method's
 183  
      * implementation throughout the course of the enhancement operation. When
 184  
      * the enhanced class is finialized, the method is added with whatever
 185  
      * contents are in its body. If the base class implements the method, then
 186  
      * the method body will include an initial call to that implementation.
 187  
      * <p>
 188  
      * At this time, this works best for void methods (since there isn't an easy
 189  
      * way to ensure code would be inserted before a final return statement).
 190  
      * 
 191  
      * @param interfaceClass
 192  
      *            the interface containing the method. If the base class does
 193  
      *            not implement the interface, then the enhanced class will have
 194  
      *            the interface added.
 195  
      * @param methodSignature
 196  
      *            the signature of the method to be added.
 197  
      * @param code
 198  
      *            the Javassist markup to be added to the body of the method.
 199  
      */
 200  
     void extendMethodImplementation(Class interfaceClass, MethodSignature methodSignature, String code);
 201  
 
 202  
     /**
 203  
      * Returns true if the class implements the specified interface. Checks the
 204  
      * base class (as identified in the specification), but <em>also</em>
 205  
      * accounts for any additional interfaces that may be added by
 206  
      * {@link #extendMethodImplementation(Class, MethodSignature, String)}.
 207  
      *
 208  
      * @param interfaceClass
 209  
      *          The class to check if the base class implements.
 210  
      *
 211  
      * @return Whether or not the specified interface is implemented by the base class
 212  
      *          being enhanced.
 213  
      */
 214  
 
 215  
     boolean implementsInterface(Class interfaceClass);
 216  
 
 217  
     /**
 218  
      * The specification defined for the component class being enhanced.
 219  
      *
 220  
      * @return The specification for the component being enhanced.
 221  
      */
 222  
     IComponentSpecification getSpecification();
 223  
 }