/// <summary>
/// Builds object mapper from OWIN environment for given .NET type.
/// </summary>
/// <param name="type">The type of object to map.</param>
public static Func <IOwinContext, object> Build(Type type)
{
if (type == null)
{
throw new ArgumentNullException("type");
}
var ctors = type.GetConstructors(BindingFlags.Public | BindingFlags.Instance);
var ctor = ctors.FirstOrDefault(c => c.GetParameters().Any(p => p.HasAttribute <BindingAttribute>()));
if (ctor != null)
{
var args = ParameterMapper.Build(ctor);
// TODO build expression tree to create instance
return(ctx => ctor.Invoke(args(ctx)));
}
var props = type
.GetProperties(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public)
.Where(p => p.CanWrite && p.GetIndexParameters().Length == 0 && p.HasAttribute <BindingAttribute>())
.ToArray();
var fields = type.GetFields(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public)
.Where(f => !f.IsLiteral && !f.IsInitOnly && f.HasAttribute <BindingAttribute>())
.ToArray();
var setters = props
.Select(p => Setter(p))
.Concat(fields.Select(f => Setter(f)))
.ToArray();
return(ctx =>
{
var instance = Activator.CreateInstance(type);
foreach (var setter in setters)
{
setter(ctx, instance);
}
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);
}
