public object[] ExtractParamsFromRequest(HttpRequest request)
{
var paramInfos = MethodInfo.GetParameters();
var queryValues = GetQueryString(request);
var paramValues = paramInfos.Select(pi =>
{
if (pi.GetCustomAttribute <FromBodyAttribute>() != null)
{
return(ContentHelper.DeserializeBodyFromRequest(pi.ParameterType, request));
}
if (IsPrimitive(pi.ParameterType))
{
return(ParseParamFromQuery(pi.ParameterType, queryValues.Get(pi.Name.ToLower()) ?? ""));
}
else
{
var instance = Activator.CreateInstance(pi.ParameterType);
var instanceProps = instance.GetType().GetProperties();
foreach (var prop in instanceProps)
{
var s = queryValues[prop.Name.ToLower()];
if (s == null)
{
continue;
}
prop.SetValue(instance, ParseParamFromQuery(prop.PropertyType, s));
}
return(instance);
}
}).ToArray();
return(paramValues);
}
/// <summary>
/// Use a service implementation as a web api endpoint
/// </summary>
/// <typeparam name="TService"></typeparam>
/// <param name="appBuilder"></param>
/// <param name="root">Not required. Root path for service endoint</param>
/// <returns></returns>
public static IApplicationBuilder UseWebApiEndpoint <TService>(this IApplicationBuilder appBuilder, string root = null)
{
var descriptors = MethodDescriptor.GetAll(typeof(TService), root);
foreach (var descriptor in descriptors)
{
appBuilder.Use(async(context, next) =>
{
if (!descriptor.IsRouteMatch(context.Request.Path.Value))
{
await next();
return;
}
var descriptorHttpMethod = descriptor.HttpMethod.ToLower();
var requestHttpMethod = context.Request.Method.ToLower();
if (descriptorHttpMethod != requestHttpMethod)
{
await next();
return;
}
var contentType = ContentHelper.GetContentType(context.Request.ContentType);
if (string.IsNullOrEmpty(contentType))
{
context.Response.StatusCode = StatusCodes.Status400BadRequest;
var info = new ExceptionInfo(new ArgumentException($"Http request must contain a 'Content-Type' header '{ContentTypes.Xml}' or '{ContentTypes.Json}'"));
await context.Response.WriteAsync(ContentHelper.SerializeBody(info, ContentTypes.Json));
return;
}
try
{
var instance = (TService)appBuilder.ApplicationServices.GetService(typeof(TService));
var instanceMtd = instance.GetType().GetMethods().First(m => {
if (m.Name != descriptor.MethodName)
{
return(false);
}
var methodParams = m.GetParameters();
var interfaceParams = descriptor.MethodInfo.GetParameters();
if (methodParams.Length != interfaceParams.Length)
{
return(false);
}
for (int n = 0; n < methodParams.Length; n++)
{
if (methodParams[n].ParameterType != interfaceParams[n].ParameterType)
{
return(false);
}
}
return(true);
});
var mtdParams = descriptor.ExtractParamsFromRequest(context.Request);
var result = instanceMtd.Invoke(instance, mtdParams);
context.Response.ContentType = contentType;
context.Response.StatusCode = StatusCodes.Status200OK;
if (instanceMtd.ReturnType.Name != "Void")
{
var text = ContentHelper.SerializeBody(result, contentType);
await context.Response.WriteAsync(text);
}
}
catch (Exception ex)
{
context.Response.StatusCode = StatusCodes.Status500InternalServerError;
var info = new ExceptionInfo(ex);
await context.Response.WriteAsync(info.ToJsonString());
}
});
}
return(appBuilder);
}
