aspnetcore/src/Microsoft.AspNet.Mvc.Xml/EnumerableWrapperProvider.cs

69 lines
2.5 KiB
C#

// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Collections.Generic;
using System.Reflection;
using Microsoft.Framework.Internal;
namespace Microsoft.AspNet.Mvc.Xml
{
/// <summary>
/// Provides a <see cref="IWrapperProvider"/> for interface types which implement
/// <see cref="IEnumerable{T}"/>.
/// </summary>
public class EnumerableWrapperProvider : IWrapperProvider
{
private readonly IWrapperProvider _wrapperProvider;
private readonly ConstructorInfo _wrappingTypeConstructor;
/// <summary>
/// Initializes an instance of <see cref="EnumerableWrapperProvider"/>.
/// </summary>
/// <param name="sourceEnumerableOfT">Type of the original <see cref="IEnumerable{T}" />
/// that is being wrapped.</param>
/// <param name="elementWrapperProvider">The <see cref="IWrapperProvider"/> for the element type.
/// Can be null.</param>
public EnumerableWrapperProvider(
[NotNull] Type sourceEnumerableOfT,
IWrapperProvider elementWrapperProvider)
{
var enumerableOfT = sourceEnumerableOfT.ExtractGenericInterface(typeof(IEnumerable<>));
if (!sourceEnumerableOfT.IsInterface() || enumerableOfT == null)
{
throw new ArgumentException(
Resources.FormatEnumerableWrapperProvider_InvalidSourceEnumerableOfT(typeof(IEnumerable<>).Name),
nameof(sourceEnumerableOfT));
}
_wrapperProvider = elementWrapperProvider;
var declaredElementType = enumerableOfT.GetGenericArguments()[0];
var wrappedElementType = elementWrapperProvider?.WrappingType ?? declaredElementType;
WrappingType = typeof(DelegatingEnumerable<,>).MakeGenericType(wrappedElementType, declaredElementType);
_wrappingTypeConstructor = WrappingType.GetConstructor(new[]
{
sourceEnumerableOfT,
typeof(IWrapperProvider)
});
}
/// <inheritdoc />
public Type WrappingType
{
get;
}
/// <inheritdoc />
public object Wrap(object original)
{
if (original == null)
{
return null;
}
return _wrappingTypeConstructor.Invoke(new object[] { original, _wrapperProvider });
}
}
}