001/*
002 * Copyright 2002-2012 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.servlet.tags.form;
018
019import java.util.Collection;
020import java.util.Iterator;
021import java.util.Map;
022import javax.servlet.jsp.JspException;
023
024import org.springframework.beans.BeanWrapper;
025import org.springframework.beans.PropertyAccessorFactory;
026import org.springframework.util.Assert;
027import org.springframework.util.ObjectUtils;
028import org.springframework.util.StringUtils;
029
030/**
031 * Abstract base class to provide common methods for implementing
032 * databinding-aware JSP tags for rendering <i>multiple</i>
033 * HTML '{@code input}' elements with a '{@code type}'
034 * of '{@code checkbox}' or '{@code radio}'.
035 *
036 * @author Juergen Hoeller
037 * @author Scott Andrews
038 * @since 2.5.2
039 */
040@SuppressWarnings("serial")
041public abstract class AbstractMultiCheckedElementTag extends AbstractCheckedElementTag {
042
043        /**
044         * The HTML '{@code span}' tag.
045         */
046        private static final String SPAN_TAG = "span";
047
048
049        /**
050         * The {@link java.util.Collection}, {@link java.util.Map} or array of objects
051         * used to generate the '{@code input type="checkbox/radio"}' tags.
052         */
053        private Object items;
054
055        /**
056         * The name of the property mapped to the '{@code value}' attribute
057         * of the '{@code input type="checkbox/radio"}' tag.
058         */
059        private String itemValue;
060
061        /**
062         * The value to be displayed as part of the '{@code input type="checkbox/radio"}' tag.
063         */
064        private String itemLabel;
065
066        /**
067         * The HTML element used to enclose the '{@code input type="checkbox/radio"}' tag.
068         */
069        private String element = SPAN_TAG;
070
071        /**
072         * Delimiter to use between each '{@code input type="checkbox/radio"}' tags.
073         */
074        private String delimiter;
075
076
077        /**
078         * Set the {@link java.util.Collection}, {@link java.util.Map} or array of objects
079         * used to generate the '{@code input type="checkbox/radio"}' tags.
080         * <p>Typically a runtime expression.
081         * @param items said items
082         */
083        public void setItems(Object items) {
084                Assert.notNull(items, "'items' must not be null");
085                this.items = items;
086        }
087
088        /**
089         * Get the {@link java.util.Collection}, {@link java.util.Map} or array of objects
090         * used to generate the '{@code input type="checkbox/radio"}' tags.
091         */
092        protected Object getItems() {
093                return this.items;
094        }
095
096        /**
097         * Set the name of the property mapped to the '{@code value}' attribute
098         * of the '{@code input type="checkbox/radio"}' tag.
099         * <p>May be a runtime expression.
100         */
101        public void setItemValue(String itemValue) {
102                Assert.hasText(itemValue, "'itemValue' must not be empty");
103                this.itemValue = itemValue;
104        }
105
106        /**
107         * Get the name of the property mapped to the '{@code value}' attribute
108         * of the '{@code input type="checkbox/radio"}' tag.
109         */
110        protected String getItemValue() {
111                return this.itemValue;
112        }
113
114        /**
115         * Set the value to be displayed as part of the
116         * '{@code input type="checkbox/radio"}' tag.
117         * <p>May be a runtime expression.
118         */
119        public void setItemLabel(String itemLabel) {
120                Assert.hasText(itemLabel, "'itemLabel' must not be empty");
121                this.itemLabel = itemLabel;
122        }
123
124        /**
125         * Get the value to be displayed as part of the
126         * '{@code input type="checkbox/radio"}' tag.
127         */
128        protected String getItemLabel() {
129                return this.itemLabel;
130        }
131
132        /**
133         * Set the delimiter to be used between each
134         * '{@code input type="checkbox/radio"}' tag.
135         * <p>By default, there is <em>no</em> delimiter.
136         */
137        public void setDelimiter(String delimiter) {
138                this.delimiter = delimiter;
139        }
140
141        /**
142         * Return the delimiter to be used between each
143         * '{@code input type="radio"}' tag.
144         */
145        public String getDelimiter() {
146                return this.delimiter;
147        }
148
149        /**
150         * Set the HTML element used to enclose the
151         * '{@code input type="checkbox/radio"}' tag.
152         * <p>Defaults to an HTML '{@code <span/>}' tag.
153         */
154        public void setElement(String element) {
155                Assert.hasText(element, "'element' cannot be null or blank");
156                this.element = element;
157        }
158
159        /**
160         * Get the HTML element used to enclose
161         * '{@code input type="checkbox/radio"}' tag.
162         */
163        public String getElement() {
164                return this.element;
165        }
166
167
168        /**
169         * Appends a counter to a specified id as well,
170         * since we're dealing with multiple HTML elements.
171         */
172        @Override
173        protected String resolveId() throws JspException {
174                Object id = evaluate("id", getId());
175                if (id != null) {
176                        String idString = id.toString();
177                        return (StringUtils.hasText(idString) ? TagIdGenerator.nextId(idString, this.pageContext) : null);
178                }
179                return autogenerateId();
180        }
181
182        /**
183         * Renders the '{@code input type="radio"}' element with the configured
184         * {@link #setItems(Object)} values. Marks the element as checked if the
185         * value matches the bound value.
186         */
187        @Override
188        @SuppressWarnings("rawtypes")
189        protected int writeTagContent(TagWriter tagWriter) throws JspException {
190                Object items = getItems();
191                Object itemsObject = (items instanceof String ? evaluate("items", items) : items);
192
193                String itemValue = getItemValue();
194                String itemLabel = getItemLabel();
195                String valueProperty =
196                                (itemValue != null ? ObjectUtils.getDisplayString(evaluate("itemValue", itemValue)) : null);
197                String labelProperty =
198                                (itemLabel != null ? ObjectUtils.getDisplayString(evaluate("itemLabel", itemLabel)) : null);
199
200                Class<?> boundType = getBindStatus().getValueType();
201                if (itemsObject == null && boundType != null && boundType.isEnum()) {
202                        itemsObject = boundType.getEnumConstants();
203                }
204
205                if (itemsObject == null) {
206                        throw new IllegalArgumentException("Attribute 'items' is required and must be a Collection, an Array or a Map");
207                }
208
209                if (itemsObject.getClass().isArray()) {
210                        Object[] itemsArray = (Object[]) itemsObject;
211                        for (int i = 0; i < itemsArray.length; i++) {
212                                Object item = itemsArray[i];
213                                writeObjectEntry(tagWriter, valueProperty, labelProperty, item, i);
214                        }
215                }
216                else if (itemsObject instanceof Collection) {
217                        final Collection<?> optionCollection = (Collection<?>) itemsObject;
218                        int itemIndex = 0;
219                        for (Iterator<?> it = optionCollection.iterator(); it.hasNext(); itemIndex++) {
220                                Object item = it.next();
221                                writeObjectEntry(tagWriter, valueProperty, labelProperty, item, itemIndex);
222                        }
223                }
224                else if (itemsObject instanceof Map) {
225                        final Map<?, ?> optionMap = (Map<?, ?>) itemsObject;
226                        int itemIndex = 0;
227                        for (Iterator it = optionMap.entrySet().iterator(); it.hasNext(); itemIndex++) {
228                                Map.Entry entry = (Map.Entry) it.next();
229                                writeMapEntry(tagWriter, valueProperty, labelProperty, entry, itemIndex);
230                        }
231                }
232                else {
233                        throw new IllegalArgumentException("Attribute 'items' must be an array, a Collection or a Map");
234                }
235
236                return SKIP_BODY;
237        }
238
239        private void writeObjectEntry(TagWriter tagWriter, String valueProperty,
240                        String labelProperty, Object item, int itemIndex) throws JspException {
241
242                BeanWrapper wrapper = PropertyAccessorFactory.forBeanPropertyAccess(item);
243                Object renderValue;
244                if (valueProperty != null) {
245                        renderValue = wrapper.getPropertyValue(valueProperty);
246                }
247                else if (item instanceof Enum) {
248                        renderValue = ((Enum<?>) item).name();
249                }
250                else {
251                        renderValue = item;
252                }
253                Object renderLabel = (labelProperty != null ? wrapper.getPropertyValue(labelProperty) : item);
254                writeElementTag(tagWriter, item, renderValue, renderLabel, itemIndex);
255        }
256
257        private void writeMapEntry(TagWriter tagWriter, String valueProperty,
258                        String labelProperty, Map.Entry<?, ?> entry, int itemIndex) throws JspException {
259
260                Object mapKey = entry.getKey();
261                Object mapValue = entry.getValue();
262                BeanWrapper mapKeyWrapper = PropertyAccessorFactory.forBeanPropertyAccess(mapKey);
263                BeanWrapper mapValueWrapper = PropertyAccessorFactory.forBeanPropertyAccess(mapValue);
264                Object renderValue = (valueProperty != null ?
265                                mapKeyWrapper.getPropertyValue(valueProperty) : mapKey.toString());
266                Object renderLabel = (labelProperty != null ?
267                                mapValueWrapper.getPropertyValue(labelProperty) : mapValue.toString());
268                writeElementTag(tagWriter, mapKey, renderValue, renderLabel, itemIndex);
269        }
270
271        private void writeElementTag(TagWriter tagWriter, Object item, Object value, Object label, int itemIndex)
272                        throws JspException {
273
274                tagWriter.startTag(getElement());
275                if (itemIndex > 0) {
276                        Object resolvedDelimiter = evaluate("delimiter", getDelimiter());
277                        if (resolvedDelimiter != null) {
278                                tagWriter.appendValue(resolvedDelimiter.toString());
279                        }
280                }
281                tagWriter.startTag("input");
282                String id = resolveId();
283                writeOptionalAttribute(tagWriter, "id", id);
284                writeOptionalAttribute(tagWriter, "name", getName());
285                writeOptionalAttributes(tagWriter);
286                tagWriter.writeAttribute("type", getInputType());
287                renderFromValue(item, value, tagWriter);
288                tagWriter.endTag();
289                tagWriter.startTag("label");
290                tagWriter.writeAttribute("for", id);
291                tagWriter.appendValue(convertToDisplayString(label));
292                tagWriter.endTag();
293                tagWriter.endTag();
294        }
295
296}