Adds a Metamorph function for generating timestamps.

(cherry picked from commit 0b882fe)

Author: cboehme

src/main/java/org/culturegraph/mf/morph/functions/Timestamp.java

@@ -0,0 +1,93 @@
+/*
+ *  Copyright 2014 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.functions;
+
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.Collections;
+import java.util.Date;
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Set;
+import java.util.TimeZone;
+
+import org.culturegraph.mf.exceptions.MorphDefException;
+
+/**
+ * This function creates a timestamp. By default it returns a unix
+ * timestamp. Other formats are and different
+ * timezones can be specified.
+ *
+ * Examples for using the function in Metamorph:
+ * <ul>
+ * 	<li>Generate a default unix timestamp: <code>&lt;timestamp /&gt;</code></li>
+ * 	<li>Generate a nicely formatted timestamp using central european time:
+ * 	<code>&lt;timestamp format="yyyy-MM-dd'T'HH:mmZ" timezone="Europe/Berlin" /&gt;</code></li>
+ * </ul>
+ *
+ * @author Michael Büchner
+ */
+public final class Timestamp extends AbstractSimpleStatelessFunction {
+
+	public static final String FORMAT_TIMESTAMP = "timestamp";
+
+	public static final String DEFAULT_FORMAT = FORMAT_TIMESTAMP;
+	public static final String DEFAULT_TIMEZONE = "UTC";
+
+	private static final int MS_PER_SECOND = 1000;
+	private static final Set<String> SUPPORTED_LANGUAGES;
+
+	private String format = DEFAULT_FORMAT;
+	private String timezone = DEFAULT_TIMEZONE;
+	private Locale locale = Locale.getDefault();
+
+	static {
+		final Set<String> set = new HashSet<String>();
+		Collections.addAll(set, Locale.getISOLanguages());
+		SUPPORTED_LANGUAGES = Collections.unmodifiableSet(set);
+	}
+
+	@Override
+	public String process(final String value) {
+		if (FORMAT_TIMESTAMP.equals(format)) {
+			return Long.toString(System.currentTimeMillis() / MS_PER_SECOND);
+		}
+		final DateFormat dateFormat;
+		try {
+			dateFormat = new SimpleDateFormat(format, locale);
+		} catch (final IllegalArgumentException e) {
+			throw new MorphDefException("The date/time format '" + format + "' is not supported. ", e);
+		}
+		dateFormat.setTimeZone(TimeZone.getTimeZone(timezone));
+		return dateFormat.format(new Date());
+	}
+
+	public void setFormat(final String format) {
+		this.format = format;
+	}
+
+	public void setTimezone(final String timezone) {
+		this.timezone = timezone;
+	}
+
+	public void setLanguage(final String language) {
+		if (!SUPPORTED_LANGUAGES.contains(language)) {
+			throw new MorphDefException("Language '" + language + "' not supported.");
+		}
+		this.locale = new Locale(language);
+	}
+
+}

src/main/resources/morph-functions.properties

@@ -21,4 +21,5 @@ buffer org.culturegraph.mf.morph.functions.Buffer
 switch-name-value org.culturegraph.mf.morph.functions.SwitchNameValue
 unique org.culturegraph.mf.morph.functions.Unique
 script org.culturegraph.mf.morph.functions.Script
-setreplace org.culturegraph.mf.morph.functions.SetReplace
+setreplace org.culturegraph.mf.morph.functions.SetReplace
+timestamp org.culturegraph.mf.morph.functions.Timestamp

src/main/resources/schemata/metamorph.xsd

@@ -659,6 +659,7 @@
 			<element ref="tns:equals" />
 			<element ref="tns:not-equals" />
 			<element ref="tns:case" />
+			<element ref="tns:timestamp" />
 			<element ref="tns:htmlanchor" />
 			<element ref="tns:trim" />
 			<element ref="tns:split" />
@@ -965,6 +966,17 @@
 		</complexType>
 	</element>
 
+	<element name="timestamp">
+		<annotation>
+			<documentation>Current timestamp/time.</documentation>
+		</annotation>
+		<complexType>
+			<attribute name="format" type="string" use="optional" default="timestamp"/>
+			<attribute name="timezone" type="string" use="optional" default="UTC"/>
+			<attribute name="language" type="string" use="optional" />
+		</complexType>
+	</element>
+
 	<element name="constant">
 		<annotation>
 			<documentation>Sets literal value to a constant.</documentation>