001package org.apache.maven.doxia.macro;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *   http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import java.util.Map;
023
024import org.apache.maven.doxia.logging.Log;
025import org.apache.maven.doxia.logging.SystemStreamLog;
026import org.apache.maven.doxia.sink.SinkEventAttributeSet;
027import org.apache.maven.doxia.sink.SinkEventAttributes;
028
029import org.codehaus.plexus.util.StringUtils;
030
031/**
032 * Abstract base class to execute <code>Macro</code>.
033 *
034 * @author <a href="mailto:jason@maven.org">Jason van Zyl</a>
035 * @version $Id$
036 * @since 1.0
037 */
038public abstract class AbstractMacro
039    implements Macro
040{
041    /** Log instance. */
042    private Log logger;
043
044    /** {@inheritDoc} */
045    public void enableLogging( Log log )
046    {
047        this.logger = log;
048    }
049
050    /**
051     * Returns a logger for this macro.
052     * If no logger has been configured, a new SystemStreamLog is returned.
053     *
054     * @return Log
055     * @since 1.1
056     */
057    protected Log getLog()
058    {
059        if ( logger == null )
060        {
061            logger = new SystemStreamLog();
062        }
063
064        return logger;
065    }
066
067    /**
068     * Check if the given parameter is required. Throws an
069     * IllegalArgumentException if paramValue is null or empty.
070     *
071     * @param paramName The name of the parameter to check.
072     * @param paramValue The parameter value.
073     * @since 1.1
074     */
075    protected void required( String paramName, String paramValue )
076    {
077        if ( StringUtils.isEmpty( paramValue ) )
078        {
079            throw new IllegalArgumentException( paramName + " is a required parameter!" );
080        }
081    }
082
083    /**
084     * Convert the Map of macro parameters to an AttributeSet.
085     * No check of validity is done, all parameters are added.
086     *
087     * @param parameters the macro parameters.
088     * @return a SinkEventAttributeSet containing the same parameters,
089     *  or null if parameters is null.
090     *
091     * @since 1.1.1.
092     */
093    protected static SinkEventAttributes getAttributesFromMap( Map<?, ?> parameters )
094    {
095        if ( parameters == null )
096        {
097            return null;
098        }
099
100        final int count = parameters.size();
101
102        if ( count <= 0 )
103        {
104            return null;
105        }
106
107        final SinkEventAttributeSet atts = new SinkEventAttributeSet( count );
108
109        for ( Map.Entry<?, ?> entry : parameters.entrySet() )
110        {
111            atts.addAttribute( entry.getKey(), entry.getValue() );
112        }
113
114        return atts;
115    }
116}