/*
* 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.MarkupElement;
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.WicketTag;
import org.apache.wicket.util.resource.ResourceStreamNotFoundException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 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
{
/** Log for reporting. */
private static final Logger log = LoggerFactory.getLogger(InheritedMarkupMarkupLoader.class);
/**
* Constructor.
*/
public InheritedMarkupMarkupLoader()
{
}
/**
*
* @see org.apache.wicket.markup.loader.IMarkupLoader#loadMarkup(org.apache.wicket.MarkupContainer,
* org.apache.wicket.markup.MarkupResourceStream,
* org.apache.wicket.markup.loader.IMarkupLoader, boolean)
*/
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);
markup = checkForMarkupInheritance(container, markup, enforceReload);
return markup;
}
/**
* The markup has just been loaded and now we check if markup inheritance applies, which is if
* <wicket:extend> is found in the markup. If yes, than load the base markups and merge the
* markup elements to create an updated (merged) list of markup elements.
*
* @param container
* The original requesting markup container
* @param markup
* The markup to checked for inheritance
* @param enforceReload
* The cache will be ignored and all, including inherited markup files, will be
* reloaded. Whatever is in the cache, it will be ignored
* @return A markup object with the the base markup elements resolved.
* @TODO move into IMarkupLoader
*/
private Markup checkForMarkupInheritance(final MarkupContainer container, final Markup markup,
final boolean 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 a MarkupStream for the markup
return markup;
}
final Markup baseMarkup = getBaseMarkup(container, markup, enforceReload);
if (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 org.apache.wicket.util.resource.Resource to get a list of all filenames tried.");
}
// Merge base and derived markup
return new MergedMarkup(markup, baseMarkup, extendIndex);
}
/**
* @param container
* @param markup
* @param enforceReload
* @return the base markup
*/
private Markup getBaseMarkup(final MarkupContainer container, final Markup markup,
final boolean enforceReload)
{
// get the base markup
Markup baseMarkup = MarkupFactory.get().getMarkup(container,
markup.getMarkupResourceStream().getMarkupClass().getSuperclass(), enforceReload);
return baseMarkup;
}
/**
* 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
* @TODO move into IMarkupLoader
*/
private int requiresBaseMarkup(final IMarkupFragment markup)
{
for (int i = 0; i < markup.size(); i++)
{
MarkupElement elem = markup.get(i);
if (elem instanceof WicketTag)
{
WicketTag wtag = (WicketTag)elem;
if (wtag.isExtendTag())
{
// Ok, inheritance is on and we must get the
// inherited markup as well.
return i;
}
}
}
return -1;
}
}