Line data    Source code

       1             : #region Copyright
       2             : // // -----------------------------------------------------------------------
       3             : // // <copyright company="Chinchilla Software Limited">
       4             : // //   Copyright Chinchilla Software Limited. All rights reserved.
       5             : // // </copyright>
       6             : // // -----------------------------------------------------------------------
       7             : #endregion
       8             : 
       9             : using System;
      10             : using System.Linq.Expressions;
      11             : 
      12             : namespace Cqrs.Infrastructure
      13             : {
      14             :         /// <summary>
      15             :         /// Adjusts <see cref="Expression"/> using <see cref="Expression.Convert(System.Linq.Expressions.Expression,System.Type)"/>
      16             :         /// </summary>
      17             :         public static class DelegateAdjuster
      18           1 :         {
      19             :                 /// <summary>
      20             :                 /// If <typeparamref name="TDerived"/> equals <typeparamref name="TBase"/> then <paramref name="source"/> is compiled using <see cref="Expression{TDelegate}.Compile()"/>
      21             :                 /// Otherwise <paramref name="source"/> is converted to type <typeparamref name="TDerived"/> from <typeparamref name="TBase"/>
      22             :                 /// </summary>
      23             :                 /// <typeparam name="TBase">The source <see cref="Type"/>.</typeparam>
      24             :                 /// <typeparam name="TDerived">The target <see cref="Type"/>.</typeparam>
      25             :                 /// <param name="source">The delegate to adjust.</param>
      26           1 :                 public static Action<TBase> CastArgument<TBase, TDerived>(Expression<Action<TDerived>> source)
      27             :                         where TDerived : TBase
      28             :                 {
      29             :                         if (typeof(TDerived) == typeof(TBase))
      30             :                         {
      31             :                                 return (Action<TBase>)((Delegate)source.Compile());
      32             :                         }
      33             : 
      34             :                         ParameterExpression sourceParameter = Expression.Parameter(typeof(TBase), "source");
      35             :                         Expression<Action<TBase>> result = Expression.Lambda<Action<TBase>>
      36             :                         (
      37             :                                 Expression.Invoke(source, Expression.Convert(sourceParameter, typeof(TDerived))),
      38             :                                 sourceParameter
      39             :                         );
      40             :                         return result.Compile();
      41             :                 }
      42             :         }
      43             : }
      44             :