#region License
/*
* Copyright 2002-2005 the original author or authors.
*
* 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.
*/
#endregion
#region Imports
using System;
using System.Collections;
using Spring.Collections;
#endregion
namespace Spring.Expressions.Processors{
/// <summary>
/// Implementation of the sort processor.
/// </summary>
/// <author>Aleksandar Seovic</author>
public class SortProcessor : ICollectionProcessor
{
/// <summary>
/// Sorts the source collection.
/// </summary>
/// <remarks>
/// Please not that this processor requires that collection elements
/// are of a uniform type and that they implement <see cref="IComparable"/>
/// interface.
/// <p/>
/// If you want to perform custom sorting based on element properties
/// you should consider using <see cref="OrderByProcessor"/> instead.
/// </remarks>
/// <param name="source">
/// The source collection to sort.
/// </param>
/// <param name="args">
/// Ignored.
/// </param>
/// <returns>
/// An array containing sorted collection elements.
/// </returns>
/// <exception cref="ArgumentException">
/// If <paramref name="source"/> collection is not empty and it is
/// neither <see cref="IList"/> nor <see cref="ISet"/>.
/// </exception>
public object Process(ICollection source, object[] args)
{
if (source == null || source.Count == 0)
{
return source;
}
bool sortAscending = true;
if (args != null && args.Length == 1 && args[0] is bool)
{
sortAscending = (bool) args[0];
}
ArrayList list = new ArrayList(source);
list.Sort();
if (!sortAscending)
{
list.Reverse();
}
Type elementType = DetermineElementType(list);
return list.ToArray(elementType);
}
private Type DetermineElementType(IList list)
{
for(int i=0;i<list.Count;i++)
{
object element = list[i];
if (element != null) return element.GetType();
}
return typeof (object);
}
}
}
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