#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
using System;
using System.Collections;
using System.Runtime.Serialization;
using Spring.Reflection.Dynamic;
namespace Spring.Expressions{
/// <summary>
/// Represents parsed function node.
/// </summary>
/// <author>Aleksandar Seovic</author>
[Serializable]
public class FunctionNode : NodeWithArguments
{
/// <summary>
/// Create a new instance
/// </summary>
public FunctionNode()
{
}
/// <summary>
/// Create a new instance from SerializationInfo
/// </summary>
protected FunctionNode(SerializationInfo info, StreamingContext context)
: base(info, context)
{
}
/// <summary>
/// Evaluates function represented by this node.
/// </summary>
/// <param name="context">Context to evaluate expressions against.</param>
/// <param name="evalContext">Current expression evaluation context.</param>
/// <returns>Result of the function evaluation.</returns>
protected override object Get(object context, EvaluationContext evalContext)
{
string name = this.getText();
object[] argValues = ResolveArguments(evalContext);
object function = evalContext.Variables[name];
// delegate?
Delegate callback = function as Delegate;
if (callback != null)
{
return InvokeDelegate(callback, argValues);
}
// lambda?
LambdaExpressionNode lambda = function as LambdaExpressionNode;
if (lambda != null)
{
try
{
return GetValueWithArguments(lambda, context, evalContext, argValues);
}
catch (ArgumentMismatchException ame)
{
throw new InvalidOperationException( "Failed executing function " + name + ": " + ame.Message );
}
}
if (function == null)
{
throw new InvalidOperationException("Function '" + name + "' is not defined.");
}
throw new InvalidOperationException("Function '" + name + "' is defined but of unknown type.");
}
private object InvokeDelegate(Delegate callback, object[] arguments)
{
return new SafeMethod(callback.Method).Invoke(callback.Target, arguments);
}
}
}
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