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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Collections.Generic;
using System.Reflection.Context.Custom;
using System.Reflection.Context.Projection;
using System.Reflection.Context.Virtual;
namespace System.Reflection.Context
{
internal sealed class IdentityReflectionContext : ReflectionContext
{
public override Assembly MapAssembly(Assembly assembly) { return assembly; }
public override TypeInfo MapType(TypeInfo type) { return type; }
}
/// <summary>
/// Represents a customizable reflection context.
/// </summary>
/// <remarks>
/// For more information about this API, see <see href="https://github.com/dotnet/docs/raw/main/docs/fundamentals/runtime-libraries/system-reflection-context-customreflectioncontext.md">Supplemental API remarks for CustomReflectionContext</see>.
/// </remarks>
public abstract partial class CustomReflectionContext : ReflectionContext
{
private readonly ReflectionContextProjector _projector;
/// <summary>
/// Initializes a new instance of the <see cref="CustomReflectionContext"/> class.
/// </summary>
protected CustomReflectionContext() : this(new IdentityReflectionContext()) { }
/// <summary>
/// Initializes a new instance of the <see cref="CustomReflectionContext"/> class with the specified reflection context as a base.
/// </summary>
/// <param name="source">The reflection context to use as a base.</param>
protected CustomReflectionContext(ReflectionContext source)
{
ArgumentNullException.ThrowIfNull(source);
SourceContext = source;
_projector = new ReflectionContextProjector(this);
}
/// <summary>
/// Gets the representation, in this reflection context, of an assembly that is represented by an object from another reflection context.
/// </summary>
/// <param name="assembly">The external representation of the assembly to represent in this context.</param>
/// <returns>The representation of the assembly in this reflection context.</returns>
public override Assembly MapAssembly(Assembly assembly)
{
ArgumentNullException.ThrowIfNull(assembly);
return _projector.ProjectAssemblyIfNeeded(assembly);
}
/// <summary>
/// Gets the representation, in this reflection context, of a type represented by an object from another reflection context.
/// </summary>
/// <param name="type">The external representation of the type to represent in this context.</param>
/// <returns>The representation of the type in this reflection context.</returns>
public override TypeInfo MapType(TypeInfo type)
{
ArgumentNullException.ThrowIfNull(type);
return _projector.ProjectTypeIfNeeded(type);
}
/// <summary>
/// When overridden in a derived class, provides a list of custom attributes for the specified member, as represented in this reflection context.
/// </summary>
/// <param name="member">The member whose custom attributes will be returned.</param>
/// <param name="declaredAttributes">A collection of the member's attributes in its current context.</param>
/// <returns>A collection that represents the custom attributes of the specified member in this reflection context.</returns>
protected virtual IEnumerable<object> GetCustomAttributes(MemberInfo member, IEnumerable<object> declaredAttributes)
{
return declaredAttributes;
}
/// <summary>
/// When overridden in a derived class, provides a list of custom attributes for the specified parameter, as represented in this reflection context.
/// </summary>
/// <param name="parameter">The parameter whose custom attributes will be returned.</param>
/// <param name="declaredAttributes">A collection of the parameter's attributes in its current context.</param>
/// <returns>A collection that represents the custom attributes of the specified parameter in this reflection context.</returns>
protected virtual IEnumerable<object> GetCustomAttributes(ParameterInfo parameter, IEnumerable<object> declaredAttributes)
{
return declaredAttributes;
}
// The default implementation of GetProperties: just return an empty list.
/// <summary>
/// When overridden in a derived class, provides a collection of additional properties for the specified type, as represented in this reflection context.
/// </summary>
/// <param name="type">The type to add properties to.</param>
/// <returns>A collection of additional properties for the specified type.</returns>
/// <remarks>
/// Override this method to specify which properties should be added to a given type. To create the properties, use the <see cref="CreateProperty(Type, string, Func{object, object?}?, Action{object, object?}?)"/> method.
/// </remarks>
protected virtual IEnumerable<PropertyInfo> AddProperties(Type type)
{
// return an empty enumeration
yield break;
}
/// <summary>
/// Creates an object that represents a property to be added to a type, to be used with the <see cref="AddProperties(Type)"/> method.
/// </summary>
/// <param name="propertyType">The type of the property to create.</param>
/// <param name="name">The name of the property to create.</param>
/// <param name="getter">A delegate that represents the property's <see langword="get"/> accessor.</param>
/// <param name="setter">A delegate that represents the property's <see langword="set"/> accessor.</param>
/// <returns>An object that represents the property.</returns>
/// <remarks>
/// Objects that are returned by this method are not complete <see cref="PropertyInfo"/> objects, and should be used only in the context of the <see cref="AddProperties(Type)"/> method.
/// </remarks>
protected PropertyInfo CreateProperty(
Type propertyType,
string name,
Func<object, object?>? getter,
Action<object, object?>? setter)
{
return new VirtualPropertyInfo(
name,
propertyType,
getter,
setter,
null,
null,
null,
this);
}
/// <summary>
/// Creates an object that represents a property to be added to a type, to be used with the <see cref="AddProperties(Type)"/> method and using the specified custom attributes.
/// </summary>
/// <param name="propertyType">The type of the property to create.</param>
/// <param name="name">The name of the property to create.</param>
/// <param name="getter">A delegate that represents the property's <see langword="get"/> accessor.</param>
/// <param name="setter">A delegate that represents the property's <see langword="set"/> accessor.</param>
/// <param name="propertyCustomAttributes">A collection of custom attributes to apply to the property.</param>
/// <param name="getterCustomAttributes">A collection of custom attributes to apply to the property's <see langword="get"/> accessor.</param>
/// <param name="setterCustomAttributes">A collection of custom attributes to apply to the property's <see langword="set"/> accessor.</param>
/// <returns>An object that represents the property.</returns>
/// <remarks>
/// Objects that are returned by this method are not complete <see cref="PropertyInfo"/> objects, and should be used only in the context of the <see cref="AddProperties(Type)"/> method.
/// </remarks>
protected PropertyInfo CreateProperty(
Type propertyType,
string name,
Func<object, object?>? getter,
Action<object, object?>? setter,
IEnumerable<Attribute>? propertyCustomAttributes,
IEnumerable<Attribute>? getterCustomAttributes,
IEnumerable<Attribute>? setterCustomAttributes)
{
return new VirtualPropertyInfo(
name,
propertyType,
getter,
setter,
propertyCustomAttributes,
getterCustomAttributes,
setterCustomAttributes,
this);
}
internal IEnumerable<PropertyInfo> GetNewPropertiesForType(CustomType type)
{
// We don't support adding properties on these types.
if (type.IsInterface || type.IsGenericParameter || type.HasElementType)
yield break;
// Passing in the underlying type.
IEnumerable<PropertyInfo> newProperties = AddProperties(type.UnderlyingType);
// Setting DeclaringType on the user provided virtual properties.
foreach (PropertyInfo prop in newProperties)
{
if (prop == null)
throw new InvalidOperationException(SR.InvalidOperation_AddNullProperty);
VirtualPropertyBase? vp = prop as VirtualPropertyBase;
if (vp == null || vp.ReflectionContext != this)
throw new InvalidOperationException(SR.InvalidOperation_AddPropertyDifferentContext);
if (vp.DeclaringType == null)
vp.SetDeclaringType(type);
else if (!vp.DeclaringType.Equals(type))
throw new InvalidOperationException(SR.InvalidOperation_AddPropertyDifferentType);
yield return prop;
}
}
internal IEnumerable<object> GetCustomAttributesOnMember(MemberInfo member, IEnumerable<object> declaredAttributes, Type attributeFilterType)
{
IEnumerable<object> attributes = GetCustomAttributes(member, declaredAttributes);
return AttributeUtils.FilterCustomAttributes(attributes, attributeFilterType);
}
internal IEnumerable<object> GetCustomAttributesOnParameter(ParameterInfo parameter, IEnumerable<object> declaredAttributes, Type attributeFilterType)
{
IEnumerable<object> attributes = GetCustomAttributes(parameter, declaredAttributes);
return AttributeUtils.FilterCustomAttributes(attributes, attributeFilterType);
}
internal Projector Projector
{
get
{
return _projector;
}
}
internal ReflectionContext SourceContext { get; }
}
}
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