Newtonsoft.Json\Serialization\DynamicValueProvider.cs

#region License

// Copyright (c) 2007 James Newton-King

//

// Permission is hereby granted, free of charge, to any person

// obtaining a copy of this software and associated documentation

// files (the "Software"), to deal in the Software without

// restriction, including without limitation the rights to use,

// copy, modify, merge, publish, distribute, sublicense, and/or sell

// copies of the Software, and to permit persons to whom the

// Software is furnished to do so, subject to the following

// conditions:

//

// The above copyright notice and this permission notice shall be

// included in all copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

// OTHER DEALINGS IN THE SOFTWARE.

#endregion

#if !PocketPC && !SILVERLIGHT

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Reflection;

using Newtonsoft.Json.Utilities;

using System.Globalization;

namespace Newtonsoft.Json.Serialization

{

  /// <summary>

  /// Get and set values for a <see cref="MemberInfo"/> using dynamic methods.

  /// </summary>

  public class DynamicValueProvider : IValueProvider

  {

    private readonly MemberInfo _memberInfo;

    private Func<object, object> _getter;

    private Action<object, object> _setter;

    /// <summary>

    /// Initializes a new instance of the <see cref="DynamicValueProvider"/> class.

    /// </summary>

    /// <param name="memberInfo">The member info.</param>

    public DynamicValueProvider(MemberInfo memberInfo)

    {

      ValidationUtils.ArgumentNotNull(memberInfo, "memberInfo");

      _memberInfo = memberInfo;

    }

    /// <summary>

    /// Sets the value.

    /// </summary>

    /// <param name="target">The target to set the value on.</param>

    /// <param name="value">The value to set on the target.</param>

    public void SetValue(object target, object value)

    {

      try

      {

        if (_setter == null)

          _setter = DynamicReflectionDelegateFactory.Instance.CreateSet<object>(_memberInfo);

#if DEBUG

        // dynamic method doesn't check whether the type is 'legal' to set

        // add this check for unit tests

        if (value == null)

        {

          if (!ReflectionUtils.IsNullable(ReflectionUtils.GetMemberUnderlyingType(_memberInfo)))

            throw new Exception("Incompatible value. Cannot set {0} to null.".FormatWith(CultureInfo.InvariantCulture, _memberInfo));

        }

        else if (!ReflectionUtils.GetMemberUnderlyingType(_memberInfo).IsAssignableFrom(value.GetType()))

        {

            throw new Exception("Incompatible value. Cannot set {0} to type {1}.".FormatWith(CultureInfo.InvariantCulture, _memberInfo, value.GetType()));

        }

#endif

        _setter(target, value);

      }

      catch (Exception ex)

      {

        throw new JsonSerializationException("Error setting value to '{0}' on '{1}'.".FormatWith(CultureInfo.InvariantCulture, _memberInfo.Name, target.GetType()), ex);

      }

    }

    /// <summary>

    /// Gets the value.

    /// </summary>

    /// <param name="target">The target to get the value from.</param>

    /// <returns>The value.</returns>

    public object GetValue(object target)

    {

      try

      {

        if (_getter == null)

          _getter = DynamicReflectionDelegateFactory.Instance.CreateGet<object>(_memberInfo);

        return _getter(target);

      }

      catch (Exception ex)

      {

        throw new JsonSerializationException("Error getting value from '{0}' on '{1}'.".FormatWith(CultureInfo.InvariantCulture, _memberInfo.Name, target.GetType()), ex);

      }

    }

  }

}

#endif