/*
* DisseminationCrosswalk.java
*
* Version: $Revision: 3761 $
*
* Date: $Date: 2009-05-07 04:18:02 +0000 (Thu, 07 May 2009) $
*
* Copyright (c) 2002-2009, The DSpace Foundation. 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 DSpace Foundation nor the names of its
* 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.content.crosswalk;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import org.dspace.authorize.AuthorizeException;
import org.dspace.content.DSpaceObject;
import org.jdom.Element;
import org.jdom.Namespace;
/**
* Dissemination Crosswalk plugin -- translate DSpace native
* metadata into an external XML format.
* <p>
* This interface describes a plugin that produces metadata in an XML-based
* format from the state of a DSpace object. Note that the object
* may be an Item, Bitstream, Community, or Collection, although most
* implementations only work on one type of object.
*
* @author Larry Stone
* @version $Revision: 3761 $
*/
public interface DisseminationCrosswalk
{
/** XSI namespace, required for xsi:schemalocation attributes */
static final Namespace XSI_NS =
Namespace.getNamespace("xsi", "http://www.w3.org/2001/XMLSchema-instance");
/**
* Get XML namespaces of the elements this crosswalk may return.
* Returns the XML namespaces (as JDOM objects) of the root element.
*
* @return array of namespaces, which may be empty.
*/
public Namespace[] getNamespaces();
/**
* Get the XML Schema location(s) of the target metadata format.
* Returns the string value of the <code>xsi:schemaLocation</code>
* attribute that should be applied to the generated XML.
* <p>
* It may return the empty string if no schema is known, but crosswalk
* authors are strongly encouraged to implement this call so their output
* XML can be validated correctly.
* @return SchemaLocation string, including URI namespace, followed by
* whitespace and URI of XML schema document, or empty string if unknown.
*/
public String getSchemaLocation();
/**
* Predicate: Can this disseminator crosswalk the given object.
* Needed by OAI-PMH server implementation.
*
* @param dso dspace object, e.g. an <code>Item</code>.
* @return true when disseminator is capable of producing metadata.
*/
public boolean canDisseminate(DSpaceObject dso);
/**
* Predicate: Does this disseminator prefer to return a list of Elements,
* rather than a single root Element?
* <p>
* Some metadata formats have an XML schema without a root element,
* for example, the Dublin Core and Qualified Dublin Core formats.
* This would be <code>true</code> for a crosswalk into QDC, since
* it would "prefer" to return a list, since any root element it has
* to produce would have to be part of a nonstandard schema. In
* most cases your implementation will want to return
* <code>false</code>
*
* @return true when disseminator prefers you call disseminateList().
*/
public boolean preferList();
/**
* Execute crosswalk, returning List of XML elements.
* Returns a <code>List</code> of JDOM <code>Element</code> objects representing
* the XML produced by the crosswalk. This is typically called when
* a list of fields is desired, e.g. for embedding in a METS document
* <code>xmlData</code> field.
* <p>
* When there are no results, an
* empty list is returned, but never <code>null</code>.
*
* @param dso the DSpace Object whose metadata to export.
* @return results of crosswalk as list of XML elements.
*
* @throws CrosswalkInternalException (<code>CrosswalkException</code>) failure of the crosswalk itself.
* @throws CrosswalkObjectNotSupported (<code>CrosswalkException</code>) Cannot crosswalk this kind of DSpace object.
* @throws IOException I/O failure in services this calls
* @throws SQLException Database failure in services this calls
* @throws AuthorizeException current user not authorized for this operation.
*/
public List disseminateList(DSpaceObject dso)
throws CrosswalkException, IOException, SQLException,
AuthorizeException;
/**
* Execute crosswalk, returning one XML root element as
* a JDOM <code>Element</code> object.
* This is typically the root element of a document.
* <p>
*
* @param dso the DSpace Object whose metadata to export.
* @return root Element of the target metadata, never <code>null</code>
*
* @throws CrosswalkInternalException (<code>CrosswalkException</code>) failure of the crosswalk itself.
* @throws CrosswalkObjectNotSupported (<code>CrosswalkException</code>) Cannot crosswalk this kind of DSpace object.
* @throws IOException I/O failure in services this calls
* @throws SQLException Database failure in services this calls
* @throws AuthorizeException current user not authorized for this operation.
*/
public Element disseminateElement(DSpaceObject dso)
throws CrosswalkException, IOException, SQLException,
AuthorizeException;
}