Catel - Part 4 of n: Unit testing with Catel

// --------------------------------------------------------------------------------------------------------------------
// <copyright file="AttributeHelper.cs" company="Catel development team">
//   Copyright (c) 2008 - 2011 Catel development team. All rights reserved.
// </copyright>
// <summary>
//   Attribute helper class.
// </summary>
// --------------------------------------------------------------------------------------------------------------------

using System;
using System.Reflection;

namespace Catel
{
    /// <summary>
    /// Attribute helper class.
    /// </summary>
    internal static class AttributeHelper
    {
        /// <summary>
        /// Tries to the get attribute.
        /// </summary>
        /// <typeparam name="U">The attribute type.</typeparam>
        /// <param name="propertyInfo">The property info.</param>
        /// <param name="attribute">The attribute.</param>
        /// <returns>
        /// 	<c>true</c> if the attribute is retrieved successfully; otherwise <c>false</c>.
        /// </returns>
        public static bool TryGetAttribute<U>(PropertyInfo propertyInfo, out U attribute) where U : Attribute
        {
            if (propertyInfo == null)
            {
            	throw new ArgumentNullException("propertyInfo");
            }

            attribute = null;
            U[] attributes = propertyInfo.GetCustomAttributes(typeof(U), false) as U[];

            if ((attributes != null) && (attributes.Length > 0))
            {
                attribute = attributes[0];
                return true;
            }

            return false;
        }
    }
}