/*
* 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 java.util.ArrayList;
import java.util.List;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.MarkupElement;
import org.apache.wicket.markup.MarkupResourceStream;
import org.apache.wicket.markup.WicketParseException;
import org.apache.wicket.markup.WicketTag;
import org.apache.wicket.markup.parser.AbstractMarkupFilter;
import org.apache.wicket.util.string.Strings;
/**
* This is a markup inline filter. It identifies xml tags which have a special meaning for Wicket.
* There are two type of tags which have a special meaning for Wicket.
* <p>
* <ul>
* <li>All tags with Wicket namespace, e.g. <wicket:remove></li>
* <li>All tags with an attribute like wicket:id="myLabel"</li>
* </ul>
*
* @author Juergen Donnerstag
*/
public final class WicketTagIdentifier extends AbstractMarkupFilter
{
/** List of well known wicket tag names */
private static List<String> wellKnownTagNames;
/**
* Construct.
*
* @param markup
* The markup as known by now
*/
public WicketTagIdentifier(final MarkupResourceStream markup)
{
super(markup);
}
/**
* Get the next tag from the next MarkupFilter in the chain and search for Wicket specific tags.
* <p>
* Note: The xml parser - the next MarkupFilter in the chain - returns XmlTags which are a
* subclass of MarkupElement. The implementation of this filter will return either ComponentTags
* or ComponentWicketTags. Both are subclasses of MarkupElement as well and both maintain a
* reference to the XmlTag. But no XmlTag is returned.
*
* @see org.apache.wicket.markup.parser.IMarkupFilter#nextElement()
* @return The next tag from markup to be processed. If null, no more tags are available
*/
@Override
protected MarkupElement onComponentTag(ComponentTag tag) throws ParseException
{
final String namespace = getWicketNamespace();
// If the form <tag wicket:id = "value"> is used
final String wicketIdValue = tag.getAttributes().getString(namespace + ":id");
// Identify tags with Wicket namespace
if (namespace.equalsIgnoreCase(tag.getNamespace()))
{
// It is <wicket:...>
tag = new WicketTag(tag.getXmlTag());
if (Strings.isEmpty(wicketIdValue))
{
// Make it a Wicket component. Otherwise it would be RawMarkup
tag.setId("_wicket_" + tag.getName());
tag.setAutoComponentTag(true);
tag.setModified(true);
}
// If the tag is not a well-known wicket namespace tag
if (!isWellKnown(tag))
{
// give up
throw new WicketParseException("Unknown tag name with Wicket namespace: '" +
tag.getName() + "'. Might be you haven't installed the appropriate resolver?",
tag);
}
}
if (wicketIdValue != null)
{
if (wicketIdValue.trim().length() == 0)
{
throw new WicketParseException(
"The wicket:id attribute value must not be empty. May be unmatched quotes?!?",
tag);
}
// Make it a wicket component. Otherwise it would be RawMarkup
tag.setId(wicketIdValue);
}
return tag;
}
/**
* Register a new well known wicket tag name (e.g. panel)
*
* @param name
*/
public final static void registerWellKnownTagName(final String name)
{
if (wellKnownTagNames == null)
{
wellKnownTagNames = new ArrayList<String>();
}
if (wellKnownTagNames.contains(name) == false)
{
wellKnownTagNames.add(name);
}
}
/**
*
* @param tag
* @return true, if name is known
*/
private boolean isWellKnown(final ComponentTag tag)
{
for (String name : wellKnownTagNames)
{
if (tag.getName().equalsIgnoreCase(name))
{
return true;
}
}
return false;
}
}