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 */
019package org.apache.maven.doxia.sink.impl;
020
021import java.util.HashSet;
022import java.util.Set;
023
024import org.apache.maven.doxia.sink.Sink;
025import org.apache.maven.doxia.sink.SinkEventAttributes;
026import org.slf4j.Logger;
027import org.slf4j.LoggerFactory;
028
029/**
030 * Validates that each anchor name only appears once per document. Otherwise logs a warning.
031 */
032public class UniqueAnchorNamesValidator extends SinkWrapper {
033
034    private static final Logger LOGGER = LoggerFactory.getLogger(UniqueAnchorNamesValidator.class);
035
036    private final Set<String> usedAnchorNames;
037
038    public UniqueAnchorNamesValidator(Sink sink) {
039        super(sink);
040        usedAnchorNames = new HashSet<>();
041    }
042
043    @Override
044    public void anchor(String name, SinkEventAttributes attributes) {
045        // assume that other anchor method signature calls this method under the hood in all relevant sink
046        // implementations
047        super.anchor(name, attributes);
048        if (!usedAnchorNames.add(name)) {
049            LOGGER.warn("{}Anchor name \"{}\" used more than once", getLocationLogPrefix(), name);
050        }
051    }
052}