/*
* Metadata.java
*
* Version: $Revision: 3705 $
*
* Date: $Date: 2009-04-11 17:02:24 +0000 (Sat, 11 Apr 2009) $
*
* Copyright (c) 2002-2005, Hewlett-Packard Company and Massachusetts
* Institute of Technology. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of the Hewlett-Packard Company nor the name of the
* Massachusetts Institute of Technology nor the names of their
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
* TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
package org.dspace.app.xmlui.wing.element;
import org.dspace.app.xmlui.wing.AttributeMap;
import org.dspace.app.xmlui.wing.WingContext;
import org.dspace.app.xmlui.wing.WingException;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.ext.LexicalHandler;
import org.xml.sax.helpers.NamespaceSupport;
/**
* This is a class representing an individual metadata field in sudo-dublin core
* format. The metadata elements carries generic metadata information in the
* form of an attribute-value pair.
*
* @author Scott Phillips
*/
public class Metadata extends TextContainer implements MetadataElement
{
/** The name of the metadata element */
public static final String E_METADATA = "metadata";
/** The name of the element attribute */
public static final String A_ELEMENT = "element";
/** The name of the qualifier attribute */
public static final String A_QUALIFIER = "qualifier";
/** The name of the language attribute */
public static final String A_LANGUAGE = "lang";
/** The metadata's element */
private String element;
/** The metadata's qualifier */
private String qualifier;
/** The metadata's language */
private String language;
/**
* Determine the addititive model for the metadata, should
* the metadata allways be added to the document or only if
* it does not allready exist?
*/
private boolean allowMultiple;
/**
* Construct a new metadata.
*
* @param element
* (Required) The element of this metadata
* @param qualifier
* (May be null) The qualifier of this metadata
* @param language
* (May be null) the language of this metadata
* @param allowMultiple
* (Required) Are multipe metadata elements with the same element,
* qualifier, and language allowed?
*/
protected Metadata(WingContext context, String element, String qualifier,
String language, boolean allowMultiple) throws WingException
{
super(context);
this.element = element;
this.qualifier = qualifier;
this.language = language;
this.allowMultiple = allowMultiple;
}
/**
* If an metadata with the same element, qualifier, and language exist
* within the document should this metadata element be added into the
* document or should only one metadata be allowed.
*/
protected boolean allowMultiple()
{
return this.allowMultiple;
}
/**
* Determine if the given element, qualifier, and lang are equal to this
* metadata.
*
* @param element
* (Required) The element of this metadata
* @param qualifier
* (May be null) The qualifier of this metadata
* @param language
* (May be null) the language of this metadata
* @return True if the given parameters are equal to this metadata.
*/
protected boolean equals(String element, String qualifier, String language)
{
// Element should never be null.
if (this.element == null || element == null)
return false;
if (stringEqualsWithNulls(this.element, element) == false)
return false;
if (stringEqualsWithNulls(this.qualifier, qualifier) == false)
return false;
if (stringEqualsWithNulls(this.language, language) == false)
return false;
// Element, qualifier, and language are equal.
return true;
}
/**
* This is just a silly private method to make the method above easier to
* read. Compare the two parameters to see if they are equal while taking
* into account nulls. So if both values are null that is considered an
* equals.
*
* The method is meant to replace the syntax current.equals(test) so that it
* works when current is null.
*
* @param current
* (May be null) The current value.
* @param test
* (May be null) The value to be compared to current
* @return If the strings are equal.
*/
private boolean stringEqualsWithNulls(String current, String test)
{
if (current == null)
{
if (test == null)
return true;
else
return false;
}
else
{
return current.equals(test);
}
}
/**
* Translate into SAX events.
*
* @param contentHandler
* (Required) The registered contentHandler where SAX events
* should be routed too.
* @param lexicalHandler
* (Required) The registered lexicalHandler where lexical
* events (such as CDATA, DTD, etc) should be routed too.
* @param namespaces
* (Required) SAX Helper class to keep track of namespaces able
* to determine the correct prefix for a given namespace URI.
*/
public void toSAX(ContentHandler contentHandler, LexicalHandler lexicalHandler,
NamespaceSupport namespaces) throws SAXException
{
AttributeMap attributes = new AttributeMap();
attributes.put(A_ELEMENT, element);
if (this.qualifier != null)
attributes.put(A_QUALIFIER, qualifier);
if (this.language != null)
attributes.put(A_LANGUAGE, language);
startElement(contentHandler, namespaces, E_METADATA, attributes);
super.toSAX(contentHandler, lexicalHandler, namespaces);
endElement(contentHandler, namespaces, E_METADATA);
}
/**
* dispose()
*/
public void dispose()
{
super.dispose();
}
}