001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.wicket.markup.parser.filter;
018
019import java.text.ParseException;
020
021import org.apache.wicket.markup.ComponentTag;
022import org.apache.wicket.markup.MarkupElement;
023import org.apache.wicket.markup.MarkupResourceStream;
024import org.apache.wicket.markup.WicketParseException;
025import org.apache.wicket.markup.WicketTag;
026import org.apache.wicket.markup.parser.AbstractMarkupFilter;
027
028
029/**
030 * This is a markup inline filter. It identifies preview regions useful for HTML designers to design
031 * the page. But they must be removed prior to sending the markup to the client. Preview regions are
032 * enclosed by <wicket:remove> tags.
033 * 
034 * @author Juergen Donnerstag
035 */
036public final class WicketRemoveTagHandler extends AbstractMarkupFilter
037{
038        /** */
039        public static final String REMOVE = "remove";
040
041        /**
042         * Construct.
043         */
044        public WicketRemoveTagHandler()
045        {
046                this(null);
047        }
048
049        public WicketRemoveTagHandler(MarkupResourceStream resourceStream)
050        {
051                super(resourceStream);
052        }
053
054        @Override
055        protected final MarkupElement onComponentTag(ComponentTag tag) throws ParseException
056        {
057                // If it is not a remove tag then we are finished
058                if (!(tag instanceof WicketTag) || !((WicketTag)tag).isRemoveTag())
059                {
060                        return tag;
061                }
062
063                // remove tag must not be open-close tags
064                if (tag.isOpenClose())
065                {
066                        throw new WicketParseException("Wicket remove tag must not be an open-close tag:", tag);
067                }
068
069                // fetch markup elements
070                MarkupElement markupElement;
071                while ((markupElement = getNextFilter().nextElement()) != null)
072                {
073                        // skip non-component tags
074                        if((markupElement instanceof ComponentTag) == false)
075                        {
076                                continue;
077                        }
078
079                        // find the corresponding close tag for the given tag
080                        ComponentTag closeTag = (ComponentTag)markupElement;
081
082                        // No Wicket component tags are allowed within the preview region.
083                        // Wicket components will a component name assigned.
084                        if (closeTag.getId() == null)
085                        {
086                                continue;
087                        }
088
089                        // The first Wicket component following the preview region open
090                        // tag, must be it's corresponding close tag.
091                        if (closeTag.closes(tag))
092                        {
093                                // The tag (from open to close) should be ignored by
094                                // MarkupParser and not be added to the Markup.
095                                tag.setIgnore(true);
096                                return tag;
097                        }
098
099                        throw new WicketParseException(
100                                "Markup remove regions must not contain Wicket component tags:", closeTag);
101                }
102
103                throw new WicketParseException(
104                        "Did not find close tag for markup remove region. Open tag:", tag);
105        }
106}