/*
* Copyright 2002-2008 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.beans.PropertyEditor;
import javax.servlet.jsp.JspException;
/**
* Abstract base class to provide common methods for
* implementing databinding-aware JSP tags for rendering an HTML '<code>input</code>'
* element with a '<code>type</code>' of '<code>checkbox</code>' or '<code>radio</code>'.
*
* @author Thomas Risberg
* @author Juergen Hoeller
* @since 2.5
*/
public abstract class AbstractCheckedElementTag extends AbstractHtmlInputElementTag {
/**
* Render the '<code>input(checkbox)</code>' with the supplied value, marking the
* '<code>input</code>' element as 'checked' if the supplied value matches the
* bound value.
*/
protected void renderFromValue(Object value, TagWriter tagWriter) throws JspException {
renderFromValue(value, value, tagWriter);
}
/**
* Render the '<code>input(checkbox)</code>' with the supplied value, marking the
* '<code>input</code>' element as 'checked' if the supplied value matches the
* bound value.
*/
protected void renderFromValue(Object item, Object value, TagWriter tagWriter) throws JspException {
PropertyEditor editor = (value != null ? getBindStatus().findEditor(value.getClass()) : null);
tagWriter.writeAttribute("value", getDisplayString(value, editor));
if (isOptionSelected(value) || (value != item && isOptionSelected(item))) {
tagWriter.writeAttribute("checked", "checked");
}
}
/**
* Determines whether the supplied value matched the selected value
* through delegating to {@link SelectedValueComparator#isSelected}.
*/
private boolean isOptionSelected(Object value) throws JspException {
return SelectedValueComparator.isSelected(getBindStatus(), value);
}
/**
* Render the '<code>input(checkbox)</code>' with the supplied value, marking
* the '<code>input</code>' element as 'checked' if the supplied Boolean is
* <code>true</code>.
*/
protected void renderFromBoolean(Boolean boundValue, TagWriter tagWriter) throws JspException {
tagWriter.writeAttribute("value", "true");
if (boundValue.booleanValue()) {
tagWriter.writeAttribute("checked", "checked");
}
}
/**
* Return a unique ID for the bound name within the current PageContext.
*/
protected String autogenerateId() throws JspException {
return TagIdGenerator.nextId(getName(), this.pageContext);
}
/**
* Writes the '<code>input</code>' element to the supplied
* {@link org.springframework.web.servlet.tags.form.TagWriter},
* marking it as 'checked' if appropriate.
*/
protected abstract int writeTagContent(TagWriter tagWriter) throws JspException;
}