001// Copyright 2006, 2008, 2009 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 015package org.apache.tapestry5.internal.bindings; 016 017import org.apache.tapestry5.PropertyConduit; 018import org.apache.tapestry5.internal.TapestryInternalUtils; 019import org.apache.tapestry5.internal.services.Invariant; 020import org.apache.tapestry5.ioc.Location; 021import org.apache.tapestry5.ioc.internal.util.TapestryException; 022 023import java.lang.annotation.Annotation; 024 025/** 026 * Base class for bindings created by the {@link org.apache.tapestry5.internal.bindings.PropBindingFactory}. A subclass 027 * of this is created at runtime. 028 */ 029public class PropBinding extends AbstractBinding implements InternalPropBinding 030{ 031 private final Object root; 032 033 private final PropertyConduit conduit; 034 035 private final String toString; 036 037 private boolean invariant; 038 039 private final String expression; 040 041 public PropBinding(final Location location, final Object root, final PropertyConduit conduit, final String expression, final String toString) 042 { 043 super(location); 044 045 this.root = root; 046 this.conduit = conduit; 047 this.expression = expression; 048 this.toString = toString; 049 050 invariant = conduit.getAnnotation(Invariant.class) != null; 051 } 052 053 /** 054 * The default implementation of get() will throw a TapestryException (binding is write only). The fabricated 055 * subclass <em>may</em> override this method (as well as set()). 056 */ 057 public Object get() 058 { 059 try 060 { 061 return conduit.get(root); 062 } 063 catch (Exception ex) 064 { 065 throw new TapestryException(ex.getMessage(), getLocation(), ex); 066 } 067 } 068 069 @Override 070 public void set(Object value) 071 { 072 try 073 { 074 conduit.set(root, value); 075 } 076 catch (Exception ex) 077 { 078 throw new TapestryException(ex.getMessage(), getLocation(), ex); 079 } 080 } 081 082 @Override 083 public String toString() 084 { 085 return toString; 086 } 087 088 /** 089 * Almost always returns false, unless the conduit provides the {@link org.apache.tapestry5.internal.services.Invariant} 090 * annotation. 091 */ 092 @Override 093 public boolean isInvariant() 094 { 095 return invariant; 096 } 097 098 @Override 099 public Class getBindingType() 100 { 101 return conduit.getPropertyType(); 102 } 103 104 @Override 105 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) 106 { 107 return conduit.getAnnotation(annotationClass); 108 } 109 110 public String getPropertyName() 111 { 112 return TapestryInternalUtils.toInternalPropertyConduit(conduit).getPropertyName(); 113 } 114 115 public String getExpression() 116 { 117 return expression; 118 } 119 120}