001/*
002    Licensed to the Apache Software Foundation (ASF) under one
003    or more contributor license agreements.  See the NOTICE file
004    distributed with this work for additional information
005    regarding copyright ownership.  The ASF licenses this file
006    to you under the Apache License, Version 2.0 (the
007    "License"); you may not use this file except in compliance
008    with the License.  You may obtain a copy of the License at
009
010       http://www.apache.org/licenses/LICENSE-2.0
011
012    Unless required by applicable law or agreed to in writing,
013    software distributed under the License is distributed on an
014    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015    KIND, either express or implied.  See the License for the
016    specific language governing permissions and limitations
017    under the License.
018 */
019
020package org.apache.wiki.tags;
021
022
023import org.apache.wiki.filters.SpamFilter;
024
025import javax.servlet.http.HttpServletRequest;
026import javax.servlet.jsp.PageContext;
027
028/**
029 * Provides hidden input fields which are checked by the {@code SpamFilter}.
030 *
031 * @since 2.11.0-M8
032 */
033public class SpamFilterInputsTag extends WikiTagBase {
034
035    /**
036     * {@inheritDoc}
037     */
038    @Override
039    public int doWikiStartTag() throws Exception {
040        final String encodingCheckInput = SpamFilter.insertInputFields( pageContext );
041        final String hashCheckInput =
042            "<input type='hidden' name='" + SpamFilter.getHashFieldName( ( HttpServletRequest ) pageContext.getRequest() ) + "'" +
043            " value='" + pageContext.getAttribute( "lastchange", PageContext.REQUEST_SCOPE ) + "' />\n";
044
045        // This following field is only for the SpamFilter to catch bots which are just randomly filling all fields and submitting.
046        // Normal user should never see this field, nor type anything in it.
047        final String botCheckInput =
048            "<input class='hidden' type='text' name='" + SpamFilter.getBotFieldName() + "' id='" + SpamFilter.getBotFieldName() + "' value='' />\n";
049        pageContext.getOut().print( encodingCheckInput + hashCheckInput + botCheckInput );
050        return SKIP_BODY;
051    }
052
053}