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