// Copyright 2004, 2005 The Apache Software Foundation
//
// 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.apache.tapestry.form;
import java.io.IOException;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.tapestry.IActionListener;
import org.apache.tapestry.IForm;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.listener.ListenerInvoker;
import org.apache.tapestry.services.DataSqueezer;
/**
* Implements a hidden field within a {@link Form}. [ <a
* href="../../../../../ComponentReference/Hidden.html">Component Reference </a>]
*
* @author Howard Lewis Ship
*/
public abstract class Hidden extends AbstractFormComponent
{
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
IForm form = getForm(cycle);
boolean formRewound = form.isRewinding();
String name = form.getElementId(this);
// If the form containing the Hidden isn't rewound, then render.
if (!formRewound)
{
// Optimiziation: if the page is rewinding (some other action or
// form was submitted), then don't bother rendering.
if (cycle.isRewinding())
return;
String externalValue = null;
if (getEncode())
{
Object value = getValue();
try
{
externalValue = getDataSqueezer().squeeze(value);
}
catch (IOException ex)
{
throw new ApplicationRuntimeException(ex.getMessage(), this, null, ex);
}
}
else
externalValue = (String) getBinding("value").getObject(String.class);
String id = getElementId();
form.addHiddenValue(name, id, externalValue);
return;
}
String externalValue = cycle.getParameter(name);
Object value = null;
if (getEncode())
{
try
{
value = getDataSqueezer().unsqueeze(externalValue);
}
catch (IOException ex)
{
throw new ApplicationRuntimeException(ex.getMessage(), this, null, ex);
}
}
else
value = externalValue;
// A listener is not always necessary ... it's easy to code
// the synchronization as a side-effect of the accessor method.
setValue(value);
getListenerInvoker().invokeListener(getListener(), this, cycle);
}
public abstract String getElementId();
/** @since 2.2 * */
public abstract DataSqueezer getDataSqueezer();
public abstract Object getValue();
public abstract void setValue(Object value);
public abstract IActionListener getListener();
/**
* Injected.
*
* @since 4.0
*/
public abstract ListenerInvoker getListenerInvoker();
/**
* Returns false. Hidden components are never disabled.
*
* @since 2.2
*/
public boolean isDisabled()
{
return false;
}
/**
* Returns true if the compent encodes object values using a
* {@link org.apache.tapestry.util.io.DataSqueezerImpl}, false if values are always Strings.
*
* @since 2.2
*/
public abstract boolean getEncode();
}