#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.Reflection;
using Spring.Core;
using Spring.Util;
#endregion
namespace Spring.Core{
/// <summary>
/// Criteria that is satisfied if the <see cref="System.Type"/> of each of the
/// arguments matches each of the parameter <see cref="System.Type"/>s of a given
/// <see cref="System.Reflection.MethodInfo"/>.
/// </summary>
/// <remarks>
/// <p>
/// If no <see cref="System.Type"/> array is passed to the overloaded constructor,
/// any method that has no parameters will satisfy an instance of this
/// class. The same effect could be achieved by passing the
/// <see cref="Spring.Util.ObjectUtils.EmptyObjects"/> array to the overloaded constructor.
/// </p>
/// </remarks>
/// <author>Rick Evans</author>
/// <author>Bruno Baia</author>
public class MethodArgumentsCriteria : ICriteria
{
#region Constructor (s) / Destructor
/// <summary>
/// Creates a new instance of the
/// <see cref="MethodArgumentsCriteria"/> class.
/// </summary>
public MethodArgumentsCriteria() : this(ObjectUtils.EmptyObjects)
{
}
/// <summary>
/// Creates a new instance of the
/// <see cref="MethodArgumentsCriteria"/> class.
/// </summary>
/// <remarks>
/// <p>
/// If the supplied <paramref name="arguments"/> array is null, then this
/// constructor uses the <see cref="System.Type.EmptyTypes"/> array.
/// </p>
/// </remarks>
/// <param name="arguments">
/// The <see cref="System.Object"/> array that this criteria will use to
/// check parameter <see cref="System.Type"/>s.
/// </param>
public MethodArgumentsCriteria(object[] arguments)
{
_parameters = ReflectionUtils.GetTypes(arguments);
}
#endregion
#region Methods
/// <summary>
/// Does the supplied <paramref name="datum"/> satisfy the criteria encapsulated by
/// this instance?
/// </summary>
/// <remarks>
/// <p>
/// This implementation respects the inheritance chain of any parameter
/// <see cref="System.Type"/>s... i.e. methods that have a base type (or
/// interface) that is assignable to the <see cref="System.Type"/> in the
/// same corresponding index of the parameter types will satisfy this
/// criteria instance.
/// </p>
/// </remarks>
/// <param name="datum">The datum to be checked by this criteria instance.</param>
/// <returns>
/// True if the supplied <paramref name="datum"/> satisfies the criteria encapsulated
/// by this instance; false if not or the supplied <paramref name="datum"/> is null.
/// </returns>
public bool IsSatisfied(object datum)
{
bool satisfied = false;
MethodInfo method = datum as MethodInfo;
if (method != null)
{
bool isParamArray = false;
Type paramArrayType = null;
ParameterInfo[] parametersBeingChecked = method.GetParameters();
if (parametersBeingChecked.Length > 0)
{
ParameterInfo lastParameter = parametersBeingChecked[parametersBeingChecked.Length - 1];
isParamArray = lastParameter.GetCustomAttributes(typeof(ParamArrayAttribute), false).Length > 0;
if (isParamArray)
{
paramArrayType = lastParameter.ParameterType.GetElementType();
}
}
if (parametersBeingChecked != null
&& parametersBeingChecked.Length == _parameters.Length)
{
satisfied = true;
for (int i = 0; i < _parameters.Length; ++i)
{
Type sourceType = _parameters[i];
Type typeBeingChecked = parametersBeingChecked[i].ParameterType;
if (!typeBeingChecked.IsAssignableFrom(sourceType))
{
if (isParamArray && i == _parameters.Length - 1)
{
if (!paramArrayType.IsAssignableFrom(sourceType))
{
satisfied = false;
break;
}
}
else
{
satisfied = false;
break;
}
}
}
}
else if (isParamArray && (_parameters.Length >= parametersBeingChecked.Length - 1))
{
satisfied = true;
for (int i = 0; i < parametersBeingChecked.Length - 1; ++i)
{
Type sourceType = _parameters[i];
Type typeBeingChecked = parametersBeingChecked[i].ParameterType;
if (!typeBeingChecked.IsAssignableFrom(sourceType))
{
satisfied = false;
break;
}
}
for (int i = parametersBeingChecked.Length - 1; i < _parameters.Length; ++i)
{
Type sourceType = _parameters[i];
if (!paramArrayType.IsAssignableFrom(sourceType))
{
satisfied = false;
break;
}
}
}
}
return satisfied;
}
#endregion
#region Fields
private readonly Type[] _parameters;
#endregion
}
}
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