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; 018 019import java.text.ParseException; 020 021import org.apache.wicket.markup.Markup; 022import org.apache.wicket.markup.MarkupElement; 023 024 025/** 026 * Wicket uses a streaming XML parser to read the markup. A chain of IMarkupFilters is used e.g. to 027 * remove comments, allow for html typical markup (some tags don't need to be closed explicitly), 028 * etc. 029 * 030 * @see org.apache.wicket.markup.MarkupParser 031 * @see org.apache.wicket.markup.MarkupFactory 032 * 033 * @author Juergen Donnerstag 034 */ 035public interface IMarkupFilter 036{ 037 /** 038 * IMarkupFilters are usually chained with the last filter retrieving the elements from the XML 039 * parser. 040 * 041 * @return The next filter in the chain, or null if the last one. 042 */ 043 IMarkupFilter getNextFilter(); 044 045 /** 046 * Set parent filter. 047 * 048 * @param parent 049 * The next element in the chain 050 */ 051 void setNextFilter(final IMarkupFilter parent); 052 053 /** 054 * Get the next MarkupElement from the parent MarkupFilter and handle it if the specific filter 055 * criteria are met. Depending on the filter, it may return the MarkupElement unchanged, 056 * modified or remove it by asking the parent handler for the next tag. 057 * 058 * @return Return the next eligible MarkupElement. Null, if no more found. 059 * @throws ParseException 060 */ 061 MarkupElement nextElement() throws ParseException; 062 063 /** 064 * Called after all filters have been processed. 065 * 066 * @param markup 067 */ 068 void postProcess(final Markup markup); 069}