/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.wicket.markup.repeater;
import java.util.Iterator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.wicket.Component;
import org.apache.wicket.DequeueContext;
import org.apache.wicket.DequeueContext.Bookmark;
import org.apache.wicket.MarkupContainer;
import org.apache.wicket.markup.IMarkupFragment;
import org.apache.wicket.markup.html.WebMarkupContainer;
import org.apache.wicket.model.IModel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Base class for repeaters. This container renders each of its children using its own markup.
*
* The children are collected using {@link #renderIterator()} method. This class will take care of
* properly positioning and rewinding its markup stream so before each child renders it points to
* the beginning of this component. Each child is rendered by a call to
* {@link #renderChild(Component)}. A typical implementation simply does
* <code>child.render();</code>.
*
* <strong>Note</strong>: the children are added during the render phase (in {@linkplain #beforeRender()} so
* most of the specializations of this class should not be used as parents of
* {@link org.apache.wicket.markup.html.form.FormComponent}s in stateless pages because the form components
* will not be available during the action phase (i.e. at
* {@link org.apache.wicket.markup.html.form.StatelessForm#onSubmit()}). Use
* {@link org.apache.wicket.markup.repeater.RepeatingView} in these cases.
*
* @author Igor Vaynberg (ivaynberg)
*/
public abstract class AbstractRepeater extends WebMarkupContainer
{
private static final long serialVersionUID = 1L;
private static final Logger log = LoggerFactory.getLogger(AbstractRepeater.class);
private static Pattern SAFE_CHILD_ID_PATTERN = Pattern.compile("^\\d+$");
/**
* Constructor
*
* @param id
*/
public AbstractRepeater(String id)
{
super(id);
}
/**
* Constructor
*
* @param id
* @param model
*/
public AbstractRepeater(String id, IModel<?> model)
{
super(id, model);
}
/**
* Returns an iterator for the collection of child components to be rendered. Users can override
* this to change order of rendered children.
*
* @return iterator over child components to be rendered
*/
protected abstract Iterator<? extends Component> renderIterator();
/**
* Renders all child items in no specified order
*/
@Override
protected final void onRender()
{
Iterator<? extends Component> it = renderIterator();
while (it.hasNext())
{
Component child = it.next();
if (child == null)
{
throw new IllegalStateException(
"The render iterator returned null for a child. Container: " + this.toString() +
"; Iterator=" + it.toString());
}
renderChild(child);
}
}
/**
* Render a single child. This method can be overridden to modify how a single child component
* is rendered.
*
* @param child
* Child component to be rendered
*/
protected void renderChild(final Component child)
{
child.render();
}
/**
* @see org.apache.wicket.Component#onBeforeRender()
*/
@Override
protected void onBeforeRender()
{
onPopulate();
if (getApplication().usesDevelopmentConfig())
{
Iterator<? extends Component> i = iterator();
while (i.hasNext())
{
Component c = i.next();
Matcher matcher = SAFE_CHILD_ID_PATTERN.matcher(c.getId());
if (!matcher.matches())
{
log.warn("Child component of repeater " + getClass().getName() + ":" + getId() +
" has a non-safe child id of " + c.getId() +
". Safe child ids must be composed of digits only.");
// do not flood the log
break;
}
}
}
super.onBeforeRender();
}
/**
* @see org.apache.wicket.MarkupContainer#getMarkup(org.apache.wicket.Component)
*/
@Override
public IMarkupFragment getMarkup(final Component child)
{
// each direct child gets the markup of this repeater
return getMarkup();
}
/**
* Callback to let the repeater know it should populate itself with its items.
*/
protected abstract void onPopulate();
@Override
public void dequeue(DequeueContext dequeue)
{
if (size() > 0)
{
// essentially what we do is for every child replace the repeater with the child in
// dequeue container stack and run the dequeue on the child. we also take care to reset
// the state of the dequeue context after we process every child.
Bookmark bookmark = dequeue.save();
for (Component child : this)
{
if (child instanceof MarkupContainer)
{
dequeue.popContainer(); // pop the repeater
MarkupContainer container = (MarkupContainer) child;
dequeue.pushContainer(container);
container.dequeue(dequeue);
dequeue.restore(bookmark);
}
}
}
dequeue.skipToCloseTag();
}
}