org.springframework.web.servlet.tags.form.CheckboxTag Maven / Gradle / Ivy
/*
* Copyright 2002-2012 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.web.servlet.tags.form;
import java.util.Collection;
import javax.servlet.jsp.JspException;
import org.springframework.web.bind.WebDataBinder;
/**
* Databinding-aware JSP tag for rendering an HTML '{@code input}'
* element with a '{@code type}' of '{@code checkbox}'.
*
* May be used in one of three different approaches depending on the
* type of the {@link #getValue bound value}.
*
*
Approach One
* When the bound value is of type {@link Boolean} then the '{@code input(checkbox)}'
* is marked as 'checked' if the bound value is {@code true}. The '{@code value}'
* attribute corresponds to the resolved value of the {@link #setValue(Object) value} property.
* Approach Two
* When the bound value is of type {@link Collection} then the '{@code input(checkbox)}'
* is marked as 'checked' if the configured {@link #setValue(Object) value} is present in
* the bound {@link Collection}.
* Approach Three
* For any other bound value type, the '{@code input(checkbox)}' is marked as 'checked'
* if the configured {@link #setValue(Object) value} is equal to the bound value.
*
* @author Rob Harrop
* @author Juergen Hoeller
* @since 2.0
*/
@SuppressWarnings("serial")
public class CheckboxTag extends AbstractSingleCheckedElementTag {
@Override
protected int writeTagContent(TagWriter tagWriter) throws JspException {
super.writeTagContent(tagWriter);
if (!isDisabled()) {
// Write out the 'field was present' marker.
tagWriter.startTag("input");
tagWriter.writeAttribute("type", "hidden");
String name = WebDataBinder.DEFAULT_FIELD_MARKER_PREFIX + getName();
tagWriter.writeAttribute("name", name);
tagWriter.writeAttribute("value", processFieldValue(name, "on", getInputType()));
tagWriter.endTag();
}
return SKIP_BODY;
}
@Override
protected void writeTagDetails(TagWriter tagWriter) throws JspException {
tagWriter.writeAttribute("type", getInputType());
Object boundValue = getBoundValue();
Class valueType = getBindStatus().getValueType();
if (Boolean.class == valueType || boolean.class == valueType) {
// the concrete type may not be a Boolean - can be String
if (boundValue instanceof String) {
boundValue = Boolean.valueOf((String) boundValue);
}
Boolean booleanValue = (boundValue != null ? (Boolean) boundValue : Boolean.FALSE);
renderFromBoolean(booleanValue, tagWriter);
}
else {
Object value = getValue();
if (value == null) {
throw new IllegalArgumentException("Attribute 'value' is required when binding to non-boolean values");
}
Object resolvedValue = (value instanceof String ? evaluate("value", value) : value);
renderFromValue(resolvedValue, tagWriter);
}
}
@Override
protected String getInputType() {
return "checkbox";
}
}