001 /*
002 * Copyright (c) 2007-2015 Concurrent, Inc. All Rights Reserved.
003 *
004 * Project and contact information: http://www.cascading.org/
005 *
006 * This file is part of the Cascading project.
007 *
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * 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, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 */
020
021 package cascading.operation.xml;
022
023 import java.beans.ConstructorProperties;
024 import java.io.IOException;
025 import java.io.StringReader;
026 import java.io.StringWriter;
027 import java.util.HashMap;
028 import java.util.Map;
029
030 import cascading.flow.FlowProcess;
031 import cascading.operation.BaseOperation;
032 import cascading.operation.Function;
033 import cascading.operation.FunctionCall;
034 import cascading.tuple.Fields;
035 import cascading.tuple.Tuple;
036 import org.ccil.cowan.tagsoup.HTMLSchema;
037 import org.ccil.cowan.tagsoup.Parser;
038 import org.ccil.cowan.tagsoup.XMLWriter;
039 import org.slf4j.Logger;
040 import org.slf4j.LoggerFactory;
041 import org.xml.sax.InputSource;
042 import org.xml.sax.SAXException;
043 import org.xml.sax.SAXNotRecognizedException;
044 import org.xml.sax.SAXNotSupportedException;
045
046 /**
047 * Class TagSoupParser uses the <a href="http://home.ccil.org/~cowan/XML/tagsoup/">Tag Soup</a> library to convert
048 * incoming HTML to clean XHTML.
049 */
050 public class TagSoupParser extends BaseOperation implements Function
051 {
052 /** Field LOG */
053 private static final Logger LOG = LoggerFactory.getLogger( TagSoupParser.class );
054
055 /** Field features */
056 private Map<String, Boolean> features;
057 /** Field schema */
058 private transient HTMLSchema schema;
059 /** Field parser */
060 private transient Parser parser;
061
062 /**
063 * Constructor TagSoupParser creates a new TagSoupParser instance.
064 *
065 * @param fieldDeclaration of type Fields
066 */
067 @ConstructorProperties({"fieldDeclaration"})
068 public TagSoupParser( Fields fieldDeclaration )
069 {
070 super( 1, fieldDeclaration );
071
072 if( fieldDeclaration.size() != 1 )
073 throw new IllegalArgumentException( "fieldDeclaration may only declare one field name: " + fieldDeclaration.print() );
074 }
075
076 private HTMLSchema getSchema()
077 {
078 if( schema == null )
079 schema = new HTMLSchema();
080
081 return schema;
082 }
083
084 private Parser getParser() throws SAXNotSupportedException, SAXNotRecognizedException
085 {
086 if( parser != null )
087 return parser;
088
089 parser = new Parser();
090 parser.setProperty( Parser.schemaProperty, getSchema() );
091
092 if( features != null )
093 {
094 for( Map.Entry<String, Boolean> entry : features.entrySet() )
095 parser.setFeature( entry.getKey(), entry.getValue() );
096 }
097
098 return parser;
099 }
100
101 /**
102 * Method setFeature allows the user to set 'features' directly on the TagSoup parser, {@link Parser#setFeature}.
103 * <p/>
104 * Note, all features are lazily added when the Parser is instantiated.
105 *
106 * @param feature of type String
107 * @param value of type boolean
108 */
109 public void setFeature( String feature, boolean value )
110 {
111 if( features == null )
112 features = new HashMap<String, Boolean>();
113
114 features.put( feature, value );
115 }
116
117 /** @see cascading.operation.Function#operate(cascading.flow.FlowProcess, cascading.operation.FunctionCall) */
118 public void operate( FlowProcess flowProcess, FunctionCall functionCall )
119 {
120 try
121 {
122 StringWriter writer = new StringWriter();
123 XMLWriter xmlWriter = new XMLWriter( writer );
124
125 xmlWriter.setPrefix( getSchema().getURI(), "" );
126 xmlWriter.setOutputProperty( XMLWriter.OMIT_XML_DECLARATION, "yes" );
127
128 InputSource source = new InputSource( new StringReader( (String) functionCall.getArguments().getObject( 0 ) ) );
129
130 getParser().setContentHandler( xmlWriter );
131
132 getParser().parse( source );
133
134 functionCall.getOutputCollector().add( new Tuple( writer.getBuffer().toString() ) );
135 }
136 catch( SAXNotRecognizedException exception )
137 {
138 LOG.warn( "ignoring TagSoup exception", exception );
139 }
140 catch( SAXNotSupportedException exception )
141 {
142 LOG.warn( "ignoring TagSoup exception", exception );
143 }
144 catch( IOException exception )
145 {
146 LOG.warn( "ignoring TagSoup exception", exception );
147 }
148 catch( SAXException exception )
149 {
150 LOG.warn( "ignoring TagSoup exception", exception );
151 }
152 }
153
154 @Override
155 public boolean equals( Object object )
156 {
157 if( this == object )
158 return true;
159 if( !( object instanceof TagSoupParser ) )
160 return false;
161 if( !super.equals( object ) )
162 return false;
163
164 TagSoupParser that = (TagSoupParser) object;
165
166 if( features != null ? !features.equals( that.features ) : that.features != null )
167 return false;
168
169 return true;
170 }
171
172 @Override
173 public int hashCode()
174 {
175 int result = super.hashCode();
176 result = 31 * result + ( features != null ? features.hashCode() : 0 );
177 return result;
178 }
179 }