New Collector EqualsFilter

With the EqualsFilter-Collector a literal is only emitted if all
received values are equal.

The following example collects values which are stored in separate
literals (037H.d and 037H.e). Then it checks if both values are equal.
If the values are equal the value is emitted. If the values are not
equal no value is emitted.

<equalsFilter name="equalsFilterd" value="${one}">
	<data source="037H.d" name="one" />
	<data source="037H.e" name="two" />
</equalsFilter>

Author: haidlas

src/main/java/org/culturegraph/mf/morph/collectors/EqualsFilter.java

@@ -0,0 +1,84 @@
+/*
+ *  Copyright 2013 Deutsche Nationalbibliothek
+ *
+ *  Licensed under the Apache License, Version 2.0 the "License";
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.culturegraph.mf.morph.collectors;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.culturegraph.mf.morph.Metamorph;
+import org.culturegraph.mf.morph.NamedValueSource;
+import org.culturegraph.mf.util.StringUtil;
+
+
+
+/**
+ * Corresponds to the <code>&lt;equalsFilter-literal&gt;</code> tag. Emits data if values in variables are all equal. 
+ * 
+ * @author Thomas Haidlas
+ */
+public final class EqualsFilter extends AbstractCollect{
+	private final Map<String, String> variables = new HashMap<String, String>();
+	private final Set<NamedValueSource> sources = new HashSet<NamedValueSource>();
+	private final Set<NamedValueSource> sourcesLeft = new HashSet<NamedValueSource>();
+	private boolean isEqual = true; 
+	
+	public EqualsFilter(final Metamorph metamorph) {
+		super(metamorph);
+		setNamedValueReceiver(metamorph);
+		this.isEqual = true;
+	}
+
+	@Override
+	protected void emit() {
+		final String name = StringUtil.format(getName(), this.variables);
+		final String value = StringUtil.format(getValue(), this.variables);
+		if(this.isEqual){
+			getNamedValueReceiver().receive(name, value, this, getRecordCount(), getEntityCount());
+		}
+	}
+
+
+	@Override
+	protected boolean isComplete() {
+		return this.sourcesLeft.isEmpty();
+	}
+
+	@Override
+	protected void receive(final String name, final String value, final NamedValueSource source) {
+		if(this.variables.size() > 0 && !this.variables.containsValue(value)){
+			this.isEqual = false;
+		}
+		this.variables.put(name, value);
+		this.sourcesLeft.remove(source);		
+	}
+
+	
+	@Override
+	public void onNamedValueSourceAdded(final NamedValueSource namedValueSource) {
+		this.sources.add(namedValueSource);
+		this.sourcesLeft.add(namedValueSource);
+	}
+
+	@Override
+	protected void clear() {
+		this.sourcesLeft.addAll(this.sources);
+		this.variables.clear();
+		this.isEqual = true;
+	}
+
+}

src/main/resources/morph-collectors.properties

@@ -5,4 +5,5 @@ entity org.culturegraph.mf.morph.collectors.Entity
 concat org.culturegraph.mf.morph.collectors.Concat
 tuples org.culturegraph.mf.morph.collectors.Tuples
 square org.culturegraph.mf.morph.collectors.Square
-range org.culturegraph.mf.morph.collectors.Range
+range org.culturegraph.mf.morph.collectors.Range
+equalsFilter org.culturegraph.mf.morph.collectors.EqualsFilter

src/main/resources/schemata/metamorph.xsd

@@ -228,6 +228,23 @@
 			<attribute name="flushWith" type="string" use="optional" />
 		</complexType>
 	</element>
+	
+	<element name="equalsFilter">
+		<complexType>
+			<sequence>
+				<group ref="tns:literal-rule" minOccurs="1" maxOccurs="unbounded" />
+				<element ref="tns:postprocess" minOccurs="0" maxOccurs="1" />
+			</sequence>
+			<attribute name="name" type="string" use="required" />
+			<attribute name="value" type="string" use="required" />
+
+			<attribute name="reset" type="boolean" use="optional"
+				default="false" />
+			<attribute name="sameEntity" type="boolean" use="optional"
+				default="false" />
+			<attribute name="flushWith" type="string" use="optional" />
+		</complexType>
+	</element>
 
 	<element name="concat">
 		<annotation>
@@ -544,6 +561,7 @@
 			<element ref="tns:square" />
 			<element ref="tns:tuples" />
 			<element ref="tns:range" />
+			<element ref="tns:equalsFilter" />
 		</choice>
 	</group>
 

src/test/java/org/culturegraph/mf/morph/collectors/CollectorTest.java

@@ -25,6 +25,6 @@
  */
 @RunWith(TestSuite.class)
 @TestDefinitions({ "CombineTest.xml", "GroupTest.xml", "ChooseTest.xml", "EntityTest.xml", "ConcatTest.xml",
-		"Nested.xml", "NestedEntity.xml", "TuplesTest.xml", "Misc.xml", "SquareTest.xml", "RangeTest.xml" })
+		"Nested.xml", "NestedEntity.xml", "TuplesTest.xml", "Misc.xml", "SquareTest.xml", "RangeTest.xml", "EqualsFilterTest.xml" })
 public final class CollectorTest {/* bind to xml test */
 }