Files
Discord.Net/src/Discord.Net.Commands/Utilities/ReflectionUtils.cs
Christopher F 40ede62e4d Remove Auto-Injection
this should be handled by #520
2017-02-11 13:38:26 -05:00

56 lines
2.2 KiB
C#

using System;
using System.Linq;
using System.Reflection;
namespace Discord.Commands
{
internal class ReflectionUtils
{
internal static T CreateObject<T>(TypeInfo typeInfo, CommandService service, IDependencyMap map = null)
=> CreateBuilder<T>(typeInfo, service)(map);
internal static Func<IDependencyMap, T> CreateBuilder<T>(TypeInfo typeInfo, CommandService service)
{
var constructors = typeInfo.DeclaredConstructors.Where(x => !x.IsStatic).ToArray();
if (constructors.Length == 0)
throw new InvalidOperationException($"No constructor found for \"{typeInfo.FullName}\"");
else if (constructors.Length > 1)
throw new InvalidOperationException($"Multiple constructors found for \"{typeInfo.FullName}\"");
var constructor = constructors[0];
System.Reflection.ParameterInfo[] parameters = constructor.GetParameters();
return (map) =>
{
object[] args = new object[parameters.Length];
for (int i = 0; i < parameters.Length; i++)
{
var parameter = parameters[i];
object arg;
if (map == null || !map.TryGet(parameter.ParameterType, out arg))
{
if (parameter.ParameterType == typeof(CommandService))
arg = service;
else if (parameter.ParameterType == typeof(IDependencyMap))
arg = map;
else
throw new InvalidOperationException($"Failed to create \"{typeInfo.FullName}\", dependency \"{parameter.ParameterType.Name}\" was not found.");
}
args[i] = arg;
}
try
{
T instance = (T)constructor.Invoke(args);
return instance;
}
catch (Exception ex)
{
throw new Exception($"Failed to create \"{typeInfo.FullName}\"", ex);
}
};
}
}
}