private static Action <IOwinContext, object> Setter(MemberInfo member)
{
var attr = member.GetAttribute <BindingAttribute>();
var name = string.IsNullOrEmpty(attr.Name) ? member.Name : attr.Name;
var type = member is PropertyInfo ? ((PropertyInfo)member).PropertyType : ((FieldInfo)member).FieldType;
var getter = Getter(attr.Target, name, type);
var setter = DynamicMethods.CompileSetter(member.DeclaringType, member);
return((ctx, instance) =>
{
var value = getter(ctx);
if (value == null)
{
return;
}
setter(instance, value);
});
}
internal static Func <IOwinContext, object> CompileInitializer(Type type)
{
var ctors = type.GetConstructors(BindingFlags.Public | BindingFlags.Instance);
if (ctors.Length > 1)
{
throw new InvalidOperationException(string.Format(
"Dependency injector cannot create instance for type {0} since it has multiple constructors.",
type.FullName));
}
var ctor = ctors[0];
var create = DynamicMethods.CompileConstructor(ctor);
var paramTypes = (from p in ctor.GetParameters() select p.ParameterType).ToArray();
var props = (from p in type.GetProperties(BindingFlags.Public | BindingFlags.Instance)
where p.GetIndexParameters().Length == 0
let setter = DynamicMethods.CompileSetter(type, p)
where setter != null
select new
{
Type = p.PropertyType,
Setter = setter
}).ToArray();
return(ctx =>
{
var serviceProvider = GetServiceProvider(ctx);
Func <Type, object> resolveDep = t =>
{
if (t == typeof(IServiceProvider))
{
return serviceProvider;
}
if (t == typeof(IOwinContext))
{
return ctx;
}
if (t == typeof(IOwinRequest))
{
return ctx.Request;
}
if (t == typeof(IOwinResponse))
{
return ctx.Response;
}
return serviceProvider.GetService(t);
};
var args = (from t in paramTypes select resolveDep(t)).ToArray();
var instance = create(args);
foreach (var prop in props)
{
var value = resolveDep(prop.Type);
prop.Setter(instance, value);
}
return instance;
});
}
/// <summary>
/// Registers methods annotated with <see cref="RouteAttribute"/> into routing pipeline.
/// </summary>
/// <typeparam name="T">Type to reflect.</typeparam>
/// <param name="mapRouteBuilder">The fluent API to register http method handlers.</param>
/// <param name="getInstance">Function to get instance of T.</param>
/// <returns></returns>
public static MapRouteBuilder UseApi <T>(this MapRouteBuilder mapRouteBuilder, Func <IOwinContext, T> getInstance)
{
if (getInstance == null)
{
throw new ArgumentNullException("getInstance");
}
var type = typeof(T);
var prefixAttr = type.GetAttribute <RoutePrefixAttribute>();
var prefix = prefixAttr != null ? prefixAttr.Prefix : string.Empty;
var serializerSettings = type.GetProperties(BindingFlags.Static | BindingFlags.FlattenHierarchy | BindingFlags.Public)
.Where(p => p.HasAttribute <ResponseSerializerSettingsAttribute>() && p.PropertyType == typeof(JsonSerializerSettings))
.Select(p => p.GetValue(null) as JsonSerializerSettings)
.FirstOrDefault();
var errorHandler = type.GetMethods(BindingFlags.Static | BindingFlags.FlattenHierarchy | BindingFlags.Public)
.Where(m => m.HasAttribute <ErrorHandlerAttribute>())
.Select(m => DynamicMethods.CompileMethod(type, m))
.FirstOrDefault();
const BindingFlags bindingFlags = BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static;
var actions = (from m in type.GetMethods(bindingFlags)
let route = m.GetAttribute <RouteAttribute>()
where route != null
select new { Method = m, Route = route }).ToList();
actions.ForEach(a =>
{
var invoke = DynamicMethods.CompileMethod(type, a.Method);
var mapper = ParameterMapper.Build(a.Method);
var returnType = a.Method.ReturnType;
var verb = GetHttpMethod(a.Method);
var pattern = AddPrefix(prefix, a.Route.Template);
mapRouteBuilder.Register(pattern, verb, async ctx =>
{
Exception error;
var args = MapParameters(ctx, mapper, out error);
if (error != null)
{
if (null != errorHandler)
{
var errorResponse = errorHandler(null, new object[] { ctx, error });
if (null != errorResponse)
{
await ctx.WriteJson(errorResponse);
}
}
else
{
ctx.Response.StatusCode = (int)HttpStatusCode.BadRequest;
await ctx.WriteJson(new { error = error.Message });
}
return;
}
var instance = a.Method.IsStatic ? (object)null : getInstance(ctx);
var result = invoke(instance, args);
var task = result as Task;
if (null != task)
{
result = await HandleAsyncResult(task, returnType);
}
if (result != null)
{
await ctx.WriteJson(result, serializerSettings);
}
});
});
return(mapRouteBuilder);
}
