/*
* 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.loader;
import java.io.IOException;
import org.apache.wicket.MarkupContainer;
import org.apache.wicket.markup.IMarkupFragment;
import org.apache.wicket.markup.Markup;
import org.apache.wicket.markup.MarkupFactory;
import org.apache.wicket.markup.MarkupNotFoundException;
import org.apache.wicket.markup.MarkupResourceStream;
import org.apache.wicket.markup.MergedMarkup;
import org.apache.wicket.markup.TagUtils;
import org.apache.wicket.util.resource.ResourceStreamNotFoundException;
import org.apache.wicket.core.util.resource.locator.ResourceStreamLocator;
/**
* Merge the 2+ markups involved in markup inheritance. From a users perspective there is only one
* markup associated with the component, the merged one.
*
* @author Juergen Donnerstag
*/
public class InheritedMarkupMarkupLoader implements IMarkupLoader
{
/**
* Constructor.
*/
public InheritedMarkupMarkupLoader()
{
}
/**
* Load the markup from the resource stream with the base MarkupLoader provided, than check if
* markup inheritance must be applied. If yes, than load the base markup and merge them.
*/
@Override
public final Markup loadMarkup(final MarkupContainer container,
final MarkupResourceStream markupResourceStream, final IMarkupLoader baseLoader,
final boolean enforceReload) throws IOException, ResourceStreamNotFoundException
{
// read and parse the markup
Markup markup = baseLoader.loadMarkup(container, markupResourceStream, null, enforceReload);
// Check if markup contains <wicket:extend> which tells us that
// we need to read the inherited markup as well.
int extendIndex = requiresBaseMarkup(markup);
if (extendIndex == -1)
{
return markup;
}
// Load the base markup
final Markup baseMarkup = getBaseMarkup(container, markup, enforceReload);
if ((baseMarkup == null) || (baseMarkup == Markup.NO_MARKUP))
{
throw new MarkupNotFoundException(
"Base markup of inherited markup not found. Component class: " +
markup.getMarkupResourceStream()
.getContainerInfo()
.getContainerClass()
.getName() +
". Enable debug messages for " + ResourceStreamLocator.class.getName() +
" to get a list of all filenames tried.");
}
// Merge base and derived markup
return new MergedMarkup(markup, baseMarkup, extendIndex);
}
/**
* Load the base markup
*
* @param container
* @param markup
* @param enforceReload
* @return the base markup
*/
private Markup getBaseMarkup(final MarkupContainer container, final Markup markup,
final boolean enforceReload)
{
final Class<?> location = markup.getMarkupResourceStream().getMarkupClass().getSuperclass();
// get the base markup
return MarkupFactory.get().getMarkup(container, location, enforceReload);
}
/**
* Check if markup contains <wicket:extend> which tells us that we need to read the
* inherited markup as well. <wicket:extend> MUST BE the first wicket tag in the markup.
* Skip raw markup
*
* @param markup
* @return == 0, if no wicket:extend was found
*/
private int requiresBaseMarkup(final IMarkupFragment markup)
{
for (int i = 0; i < markup.size(); i++)
{
if (TagUtils.isExtendTag(markup, i))
{
// Ok, inheritance is on and we must get the
// inherited markup as well.
return i;
}
}
return -1;
}
}