001 // Copyright 2004, 2005 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
015 package org.apache.tapestry.valid;
016
017 import java.text.MessageFormat;
018 import java.util.HashMap;
019 import java.util.Locale;
020 import java.util.Map;
021 import java.util.ResourceBundle;
022
023 import org.apache.hivemind.HiveMind;
024 import org.apache.hivemind.Resource;
025 import org.apache.hivemind.util.ClasspathResource;
026 import org.apache.hivemind.util.PropertyUtils;
027 import org.apache.tapestry.IEngine;
028 import org.apache.tapestry.IForm;
029 import org.apache.tapestry.IMarkupWriter;
030 import org.apache.tapestry.IRequestCycle;
031 import org.apache.tapestry.IScript;
032 import org.apache.tapestry.PageRenderSupport;
033 import org.apache.tapestry.TapestryUtils;
034 import org.apache.tapestry.engine.IScriptSource;
035 import org.apache.tapestry.form.IFormComponent;
036
037 /**
038 * Abstract base class for {@link IValidator}. Supports a required and locale property.
039 *
040 * @author Howard Lewis Ship
041 * @since 1.0.8
042 */
043
044 public abstract class BaseValidator implements IValidator
045 {
046 /**
047 * Input Symbol used to represent the field being validated.
048 *
049 * @see #processValidatorScript(String, IRequestCycle, IFormComponent, Map)
050 * @since 2.2
051 */
052
053 public static final String FIELD_SYMBOL = "field";
054
055 /**
056 * Input symbol used to represent the validator itself to the script.
057 *
058 * @see #processValidatorScript(String, IRequestCycle, IFormComponent, Map)
059 * @since 2.2
060 */
061
062 public static final String VALIDATOR_SYMBOL = "validator";
063
064 /**
065 * Input symbol used to represent the {@link IForm}containing the field to the script.
066 *
067 * @see #processValidatorScript(String, IRequestCycle, IFormComponent, Map)
068 * @since 2.2
069 */
070
071 public static final String FORM_SYMBOL = "form";
072
073 /**
074 * Output symbol set by the script asthe name of the validator JavaScript function. The function
075 * implemented must return true or false (true if the field is valid, false otherwise). After
076 * the script is executed, the function is added to the {@link IForm}as a
077 * {@link org.apache.tapestry.form.FormEventType#SUBMIT}.
078 *
079 * @see #processValidatorScript(String, IRequestCycle, IFormComponent, Map)
080 * @since 2.2
081 */
082
083 public static final String FUNCTION_SYMBOL = "function";
084
085 private boolean _required;
086
087 /** @since 3.0 */
088
089 private String _requiredMessage;
090
091 /**
092 * @since 2.2
093 */
094
095 private boolean _clientScriptingEnabled = false;
096
097 /**
098 * Standard constructor. Leaves locale as system default and required as false.
099 */
100
101 public BaseValidator()
102 {
103 }
104
105 /**
106 * Allow the validator to be initialized with a property initialization string.
107 *
108 * @since 4.0
109 */
110 public BaseValidator(String initializer)
111 {
112 PropertyUtils.configureProperties(this, initializer);
113 }
114
115 protected BaseValidator(boolean required)
116 {
117 _required = required;
118 }
119
120 public boolean isRequired()
121 {
122 return _required;
123 }
124
125 public void setRequired(boolean required)
126 {
127 _required = required;
128 }
129
130 /**
131 * Gets a pattern, either as the default value, or as a localized key. If override is null, then
132 * the key from the <code>org.apache.tapestry.valid.ValidationStrings</code>
133 * {@link ResourceBundle}(in the specified locale) is used. The pattern can then be used with
134 * {@link #formatString(String, Object[])}.
135 * <p>
136 * Why do we not just lump these strings into TapestryStrings.properties? because
137 * TapestryStrings.properties is localized to the server's locale, which is fine for the
138 * logging, debugging and error messages it contains. For field validation, whose errors are
139 * visible to the end user normally, we want to localize to the page's locale.
140 *
141 * @param override
142 * The override value for the localized string from the bundle.
143 * @param key
144 * used to lookup pattern from bundle, if override is null.
145 * @param locale
146 * used to get right localization of bundle.
147 * @since 3.0
148 */
149
150 protected String getPattern(String override, String key, Locale locale)
151 {
152 if (override != null)
153 return override;
154
155 ResourceBundle strings = ResourceBundle.getBundle(
156 "org.apache.tapestry.valid.ValidationStrings",
157 locale);
158
159 return strings.getString(key);
160 }
161
162 /**
163 * Gets a string from the standard resource bundle. The string in the bundle is treated as a
164 * pattern for {@link MessageFormat#format(java.lang.String, java.lang.Object[])}.
165 *
166 * @param pattern
167 * string the input pattern to be used with
168 * {@link MessageFormat#format(java.lang.String, java.lang.Object[])}. It may
169 * contain replaceable parameters, {0}, {1}, etc.
170 * @param args
171 * the arguments used to fill replaceable parameters {0}, {1}, etc.
172 * @since 3.0
173 */
174
175 protected String formatString(String pattern, Object[] args)
176 {
177 return MessageFormat.format(pattern, args);
178 }
179
180 /**
181 * Convienience method for invoking {@link #formatString(String, Object[])}.
182 *
183 * @since 3.0
184 */
185
186 protected String formatString(String pattern, Object arg)
187 {
188 return formatString(pattern, new Object[]
189 { arg });
190 }
191
192 /**
193 * Convienience method for invoking {@link #formatString(String, Object[])}.
194 *
195 * @since 3.0
196 */
197
198 protected String formatString(String pattern, Object arg1, Object arg2)
199 {
200 return formatString(pattern, new Object[]
201 { arg1, arg2 });
202 }
203
204 /**
205 * Invoked to check if the value is null. If the value is null (or empty), but the required flag
206 * is set, then this method throws a {@link ValidatorException}. Otherwise, returns true if the
207 * value is null.
208 */
209
210 protected boolean checkRequired(IFormComponent field, String value) throws ValidatorException
211 {
212 boolean isEmpty = HiveMind.isBlank(value);
213
214 if (_required && isEmpty)
215 throw new ValidatorException(buildRequiredMessage(field), ValidationConstraint.REQUIRED);
216
217 return isEmpty;
218 }
219
220 /**
221 * Builds an error message indicating a value for a required field was not supplied.
222 *
223 * @since 3.0
224 */
225
226 protected String buildRequiredMessage(IFormComponent field)
227 {
228 String pattern = getPattern(_requiredMessage, "field-is-required", field.getPage()
229 .getLocale());
230
231 return formatString(pattern, field.getDisplayName());
232 }
233
234 /**
235 * This implementation does nothing. Subclasses may supply their own implementation.
236 *
237 * @since 2.2
238 */
239
240 public void renderValidatorContribution(IFormComponent field, IMarkupWriter writer,
241 IRequestCycle cycle)
242 {
243 }
244
245 /**
246 * Invoked (from sub-class implementations of
247 * {@link #renderValidatorContribution(IFormComponent, IMarkupWriter, IRequestCycle)}to process
248 * a standard validation script. This expects that:
249 * <ul>
250 * <li>The {@link IFormComponent}is (ultimately) wrapped by a {@link Body}
251 * <li>The script generates a symbol named "function" (as per {@link #FUNCTION_SYMBOL})
252 * </ul>
253 *
254 * @param scriptPath
255 * the resource path of the script to execute
256 * @param cycle
257 * The active request cycle
258 * @param field
259 * The field to be validated
260 * @param symbols
261 * a set of input symbols needed by the script. These symbols are augmented with
262 * symbols for the field, form and validator. symbols may be null, but will be
263 * modified if not null.
264 * @throws ApplicationRuntimeException
265 * if there's an error processing the script.
266 * @since 2.2
267 */
268
269 protected void processValidatorScript(String scriptPath, IRequestCycle cycle,
270 IFormComponent field, Map symbols)
271 {
272 IEngine engine = field.getPage().getEngine();
273 IScriptSource source = engine.getScriptSource();
274 IForm form = field.getForm();
275
276 Map finalSymbols = (symbols == null) ? new HashMap() : symbols;
277
278 finalSymbols.put(FIELD_SYMBOL, field);
279 finalSymbols.put(FORM_SYMBOL, form);
280 finalSymbols.put(VALIDATOR_SYMBOL, this);
281
282 Resource location = new ClasspathResource(engine.getClassResolver(), scriptPath);
283
284 IScript script = source.getScript(location);
285
286 // If there's an error, report it against the field (this validator object doesn't
287 // have a location).
288
289 PageRenderSupport pageRenderSupport = TapestryUtils.getPageRenderSupport(cycle, field);
290
291 script.execute(cycle, pageRenderSupport, finalSymbols);
292 }
293
294 /**
295 * Returns true if client scripting is enabled. Some validators are capable of generating
296 * client-side scripting to perform validation when the form is submitted. By default, this flag
297 * is false and subclasses should check it (in
298 * {@link #renderValidatorContribution(IFormComponent, IMarkupWriter, IRequestCycle)}) before
299 * generating client side script.
300 *
301 * @since 2.2
302 */
303
304 public boolean isClientScriptingEnabled()
305 {
306 return _clientScriptingEnabled;
307 }
308
309 public void setClientScriptingEnabled(boolean clientScriptingEnabled)
310 {
311 _clientScriptingEnabled = clientScriptingEnabled;
312 }
313
314 public String getRequiredMessage()
315 {
316 return _requiredMessage;
317 }
318
319 /**
320 * Overrides the <code>field-is-required</code> bundle key. Parameter {0} is the display name
321 * of the field.
322 *
323 * @since 3.0
324 */
325
326 public void setRequiredMessage(String string)
327 {
328 _requiredMessage = string;
329 }
330
331 }