/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation", "Tapestry"
* must not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* or "Tapestry", nor may "Apache" or "Tapestry" appear in their
* name, without prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE TAPESTRY CONTRIBUTOR COMMUNITY
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.tapestry.contrib.form;
import java.io.IOException;
import org.apache.commons.lang.StringUtils;
import org.apache.tapestry.ApplicationRuntimeException;
import org.apache.tapestry.IActionListener;
import org.apache.tapestry.IBinding;
import org.apache.tapestry.IForm;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.Tapestry;
import org.apache.tapestry.form.AbstractFormComponent;
import org.apache.tapestry.request.RequestContext;
import org.apache.tapestry.util.io.DataSqueezer;
/**
* A conditional element on a page which will render its wrapped elements
* zero or one times.
*
* This component is a variant of {@link org.apache.tapestry.components.Conditional},
* but is designed for operation in a form. The component parameters are stored in
* hidden fields during rendering and are taken from those fields during the rewind,
* thus no StaleLink exceptions occur.
*
* [<a href="../../../../../ComponentReference/Conditional.html">Component Reference</a>]
*
* @author Mindbridge
* @version $Id: FormConditional.java,v 1.1 2003/09/06 14:04:43 mindbridge Exp $
* @since 3.0
*
**/
public abstract class FormConditional extends AbstractFormComponent
{
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
IForm form = getForm(cycle);
boolean cycleRewinding = cycle.isRewinding();
// If the cycle is rewinding, but not this particular form,
// then do nothing (don't even render the body).
if (cycleRewinding && !form.isRewinding())
return;
String name = form.getElementId(this);
boolean condition = getCondition(cycle, form, name);
boolean invert = getInvert(cycle, form, name);
// call listener
IActionListener listener = getListener();
if (listener != null)
listener.actionTriggered(this, cycle);
// render the component body only if the condition is different from the invert
if (condition != invert) {
String element = getElement();
boolean render = cycleRewinding && StringUtils.isNotEmpty(element);
if (render)
{
writer.begin(element);
renderInformalParameters(writer, cycle);
}
renderBody(writer, cycle);
if (render)
writer.end(element);
}
}
private boolean getCondition(IRequestCycle cycle, IForm form, String name)
{
boolean condition;
if (!cycle.isRewinding())
{
condition = getCondition();
writeValue(form, name, condition);
}
else
{
RequestContext context = cycle.getRequestContext();
String submittedConditions[] = context.getParameters(name);
condition = convertValue(submittedConditions[0]);
}
IBinding conditionValueBinding = getConditionValueBinding();
if (conditionValueBinding != null)
conditionValueBinding.setBoolean(condition);
return condition;
}
private boolean getInvert(IRequestCycle cycle, IForm form, String name)
{
boolean invert;
if (!cycle.isRewinding())
{
invert = getInvert();
writeValue(form, name, invert);
}
else
{
RequestContext context = cycle.getRequestContext();
String submittedConditions[] = context.getParameters(name);
invert = convertValue(submittedConditions[1]);
}
IBinding invertValueBinding = getInvertValueBinding();
if (invertValueBinding != null)
invertValueBinding.setBoolean(invert);
return invert;
}
private void writeValue(IForm form, String name, boolean value)
{
String externalValue;
Object booleanValue = new Boolean(value);
try
{
externalValue = getDataSqueezer().squeeze(booleanValue);
}
catch (IOException ex)
{
throw new ApplicationRuntimeException(
Tapestry.format("FormConditional.unable-to-convert-value", booleanValue),
this,
null,
ex);
}
form.addHiddenValue(name, externalValue);
}
private boolean convertValue(String value)
{
try
{
Object booleanValue = getDataSqueezer().unsqueeze(value);
return Tapestry.evaluateBoolean(booleanValue);
}
catch (IOException ex)
{
throw new ApplicationRuntimeException(
Tapestry.format("FormConditional.unable-to-convert-string", value),
this,
null,
ex);
}
}
private DataSqueezer getDataSqueezer()
{
return getPage().getEngine().getDataSqueezer();
}
public boolean isDisabled()
{
return false;
}
public abstract boolean getCondition();
public abstract boolean getInvert();
public abstract String getElement();
public abstract IBinding getConditionValueBinding();
public abstract IBinding getInvertValueBinding();
public abstract IActionListener getListener();
}