// 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 java.util.Iterator;
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.Tapestry;
import org.apache.tapestry.coerce.ValueConverter;
import org.apache.tapestry.listener.ListenerInvoker;
import org.apache.tapestry.services.DataSqueezer;
/**
* A specialized component used to edit a list of items within a form; it is similar to a
* {@link org.apache.tapestry.components.Foreach}but leverages hidden inputs within the
* <form> to store the items in the list. [ <a
* href="../../../../../ComponentReference/ListEdit.html">Component Reference </a>]
*
* @author Howard Lewis Ship
* @since 1.0.2
*/
public abstract class ListEdit extends AbstractFormComponent
{
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
Iterator i = null;
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 indexBound = isParameterBound("index");
if (!cycleRewinding)
{
i = getSource();
}
else
{
String[] submittedValues = cycle.getParameters(name);
i = (Iterator) getValueConverter().coerceValue(submittedValues, Iterator.class);
}
// If the source (when rendering), or the submitted values (on submit)
// are null, then skip the remainder (nothing to update, nothing to
// render).
if (i == null)
return;
int index = 0;
String element = getElement();
while (i.hasNext())
{
Object value = null;
if (indexBound)
setIndex(index++);
if (cycleRewinding)
value = convertValue((String) i.next());
else
{
value = i.next();
writeValue(form, name, value);
}
setValue(value);
getListenerInvoker().invokeListener(getListener(), this, cycle);
if (element != null)
{
writer.begin(element);
renderInformalParameters(writer, cycle);
}
renderBody(writer, cycle);
if (element != null)
writer.end();
}
}
private void writeValue(IForm form, String name, Object value)
{
String externalValue;
try
{
externalValue = getDataSqueezer().squeeze(value);
}
catch (IOException ex)
{
throw new ApplicationRuntimeException(Tapestry.format(
"ListEdit.unable-to-convert-value",
value), this, null, ex);
}
form.addHiddenValue(name, externalValue);
}
private Object convertValue(String value)
{
try
{
return getDataSqueezer().unsqueeze(value);
}
catch (IOException ex)
{
throw new ApplicationRuntimeException(Tapestry.format(
"ListEdit.unable-to-convert-string",
value), this, null, ex);
}
}
public abstract String getElement();
/** @since 2.2 * */
public abstract IActionListener getListener();
/** @since 3.0 * */
public boolean isDisabled()
{
return false;
}
/** @since 4.0 */
public abstract Iterator getSource();
/** @since 4.0 */
public abstract void setValue(Object value);
/** @since 4.0 */
public abstract void setIndex(int index);
/** @since 4.0 */
public abstract DataSqueezer getDataSqueezer();
/** @since 4.0 */
public abstract ValueConverter getValueConverter();
/**
* Injected.
*
* @since 4.0
*/
public abstract ListenerInvoker getListenerInvoker();
}