/**
* Copyright 2011 meltmedia
*
* 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.xchain.namespaces.hibernate;
import org.apache.commons.jxpath.JXPathContext;
import org.hibernate.Query;
import org.xchain.annotations.Attribute;
import org.xchain.annotations.AttributeType;
import org.xchain.annotations.Element;
/**
* <p>The <code>first-result</code> command sets the FirstResult on the parent Query.</p>
*
* <p>This must reference a <code>query</code>.</p>
*
* <code class="source">
* <xchain:session xmlns:xchain="http://www.xchain.org/hibernate/1.0">
* <xchain:transaction>
* ...
* <xchain:query query="'from entity'">
* ...
* <xchain:first-result start="'10'"/>
* ...
* </xchain:query>
* ...
* </xchain:transaction>
* </xchain:session>
* </code>
*
* @author Devon Tackett
* @author Christian Trimble
*
* @see QueryCommand
* @see org.hibernate.Query#setFirstResult(int)
*/
@Element(localName="first-result")
public abstract class FirstResultCommand
extends AbstractQueryCommand
{
/**
* The start index to retrieve results.
*/
@Attribute(localName="start", type=AttributeType.JXPATH_VALUE)
public abstract Integer getStart( JXPathContext context );
public abstract boolean hasStart();
public boolean execute( JXPathContext context )
throws Exception
{
if (!hasStart())
throw new Exception("A FirstResult must have a start.");
Query query = getQuery(context);
if (query == null)
throw new Exception("A query must be specified.");
query.setFirstResult(getStart(context));
// return false and allow other chains to execute.
return false;
}
}