/*
* 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.parser.filter;
import java.text.ParseException;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.MarkupElement;
import org.apache.wicket.markup.WicketTag;
import org.apache.wicket.markup.parser.AbstractMarkupFilter;
/**
* This is a markup inline filter. It identifies preview regions useful for HTML designers to design
* the page. But they must be removed prior to sending the markup to the client. Preview regions are
* enclosed by <wicket:remove> tags.
*
* @author Juergen Donnerstag
*/
public final class WicketRemoveTagHandler extends AbstractMarkupFilter
{
static
{
// register "wicket:remove"
WicketTagIdentifier.registerWellKnownTagName("remove");
}
/**
* Construct.
*/
public WicketRemoveTagHandler()
{
}
/**
* Removes preview regions enclosed by <wicket:remove> tags. Note that for obvious
* reasons, nested components are not allowed.
*
* @see org.apache.wicket.markup.parser.IMarkupFilter#nextTag()
* @return The next tag to be processed. Null, if not more tags are available
*/
public final MarkupElement nextTag() throws ParseException
{
// Get the next tag from the next MarkupFilter in the chain
// If null, no more tags are available
final ComponentTag openTag = (ComponentTag)getParent().nextTag();
if (openTag == null)
{
return openTag;
}
// If it is not a remove tag, than we are finished
if (!(openTag instanceof WicketTag) || !((WicketTag)openTag).isRemoveTag())
{
return openTag;
}
// remove tag must not be open-close tags
if (openTag.isOpenClose())
{
throw new ParseException("Wicket remove tag must not be an open-close tag: " +
openTag.toUserDebugString(), openTag.getPos());
}
// Find the corresponding close tag and remove all tags in between
ComponentTag closeTag;
while (null != (closeTag = (ComponentTag)getParent().nextTag()))
{
// No Wicket component tags are allowed within the preview region.
// Wicket components will a component name assigned.
if (closeTag.getId() == null)
{
continue;
}
// The first Wicket component following the preview region open
// tag, must be it's corresponding close tag.
if (closeTag.closes(openTag))
{
// The tag (from open to close) should be ignored by
// MarkupParser and not be added to the Markup.
openTag.setIgnore(true);
return openTag;
}
throw new ParseException(
"Markup remove regions must not contain Wicket component tags. tag: " +
closeTag.toUserDebugString(), closeTag.getPos());
}
throw new ParseException("Did not find close tag for markup remove region. Open tag: " +
openTag.toUserDebugString(), openTag.getPos());
}
}