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1
56 package org.objectstyle.cayenne.swing;
57
58 import ognl.Ognl;
59 import ognl.OgnlException;
60
61 import org.objectstyle.cayenne.CayenneRuntimeException;
62 import org.objectstyle.cayenne.util.Util;
63 import org.objectstyle.cayenne.validation.ValidationException;
64
65
68 public abstract class BindingBase implements ObjectBinding {
70
71 private Object  compiled;
72
73 protected Object context;
74 protected String expression;
75
76 protected BindingDelegate delegate;
77 protected boolean modelUpdateDisabled;
78
79 protected boolean usingNullForEmptyStrings;
80 protected boolean checkingForValueChange;
81
82 static Throwable unwind(Throwable th) {
83 if (th instanceof OgnlException) {
84 Throwable reason = ((OgnlException) th).getReason();
85 return (reason != null) ? unwind(reason) : th;
86 }
87 else {
88 return Util.unwindException(th);
89 }
90 }
91
92 public BindingBase(String propertyExpression) {
93
94 try {
95 this.compiled = Ognl.parseExpression(propertyExpression);
96 }
97 catch (OgnlException ex) {
98 throw new CayenneRuntimeException("Invalid expression - "
99 + propertyExpression, BindingBase.unwind(ex));
100 }
101
102 this.expression = propertyExpression;
103 }
104
105 public Object getContext() {
106 return context;
107 }
108
109 public void setContext(Object object) {
110 this.context = object;
111 }
112
113 public boolean isCheckingForValueChange() {
114 return checkingForValueChange;
115 }
116
117 public void setCheckingForValueChange(boolean checkingForValueChange) {
118 this.checkingForValueChange = checkingForValueChange;
119 }
120
121 public boolean isUsingNullForEmptyStrings() {
122 return usingNullForEmptyStrings;
123 }
124
125 public void setUsingNullForEmptyStrings(boolean b) {
126 this.usingNullForEmptyStrings = b;
127 }
128
129 public String getExpression() {
130 return expression;
131 }
132
133 public BindingDelegate getDelegate() {
134 return delegate;
135 }
136
137 public void setDelegate(BindingDelegate delegate) {
138 this.delegate = delegate;
139 }
140
141
145 public void setValue(Object value) {
146 if (context == null) {
147 throw new BindingException("No context");
148 }
149
150 try {
151
154 if (modelUpdateDisabled) {
155 return;
156 }
157
158 Object oldValue = null;
159
160 modelUpdateDisabled = true;
161 try {
162
163 if (delegate != null) {
164 oldValue = getValue();
166 }
167
168 if (isUsingNullForEmptyStrings() && "".equals(value)) {
169 value = null;
170 }
171
172 if (isCheckingForValueChange()) {
173
175 Object existingValue = (delegate != null) ? oldValue : getValue();
176 if (Util.nullSafeEquals(value, existingValue)) {
177 return;
178 }
179 }
180
181 Ognl.setValue(compiled, context, value);
182 }
183 finally {
184 modelUpdateDisabled = false;
185 }
186
187 if (delegate != null) {
188 delegate.modelUpdated(this, oldValue, value);
189 }
190 }
191 catch (OgnlException ex) {
192 processException(ex);
193 }
194 }
195
196
199 public Object getValue() {
200 if (context == null) {
201 throw new BindingException("No context");
202 }
203
204 try {
205 return Ognl.getValue(compiled, context);
206 }
207 catch (OgnlException ex) {
208 processException(ex);
209 return null;
210 }
211 }
212
213 protected void processException(Throwable th) throws ValidationException,
214 BindingException {
215 Throwable root = BindingBase.unwind(th);
216 if (root instanceof ValidationException) {
217 throw (ValidationException) root;
218 }
219 else if (root instanceof NumberFormatException ) {
220 throw new ValidationException("Invalid numeric string");
221 }
222
223 throw new BindingException("Evaluation failed in context: " + context, root);
224 }
225
226 } |
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