Getting error on Nop Commerce application - asp.net-mvc

I am getting error like
An exception of type 'Autofac.Core.DependencyResolutionException' occurred in Autofac.dll but was not handled in user code
Additional information: An exception was thrown while invoking the constructor 'Void .ctor()' on type 'UsaEpayService'.
Invalid URI: The URI is empty.
Getting above exception on Resolve -
Path : Libraries\Nop.Core\Infrastructure\DependencyManagement\ContainerManager.cs
Here is my code:
public virtual object Resolve(Type type, ILifetimeScope scope = null)
{
if (scope == null)
{
//no scope specified
scope = Scope();
}
return scope.Resolve(type);
}
I have cross-posted this here.

Related

Automatically throw 404 exception from action method if entity object is null

For example, we have simple action method to show any book with proper id:
public ActionResult GetBook(int id) // id = 123456789
{
var book = dataManager.Books.GetBookById(id); // == null
logger.Info("Getting book with id " + book.Id);
return View(book);
}
If id parameter is not valid we get 500 error because there is no book with that id.
We have to handle this situation manually if we need to throw 404 error, like this:
if (book == null)
{
return HttpNotFound();
}
Is it possible to switch 500-error to 404-error for all action methods somewhere in web-application (custom filter, request pipeline)?
Technically you could, by installing an error handler, rewrite any 500 Internal Server Error to a 404 Not Found in Application_Error() as explained in ASP.NET MVC 5 error handling.
However, you seem to want to let your code throw a NullReferenceException on a null book in book.Id, and turn that exception into a 404.
You really shouldn't be doing that in this case, because this will hide programming errors, because you will miss the exceptions where this happened unintentionally.
So: just do this explicitly where you do expect a null. The code you showed is exactly what you need:
if (book == null)
{
return HttpNotFound();
}
I found this helpful Bulk 301 Redirect
I test then throw a 302
try
{
------
}
catch
{
throw new HttpException(302, "not found");
}
Catch the exception in the Global.asax and look up a redirect csv file
protected void Application_Error()
{
Exception exception = Server.GetLastError();
Response.Clear();
Server.ClearError();
HttpException ex = exception as HttpException;
if (ex.GetHttpCode() == 404 || ex.GetHttpCode() == 302 || ex.GetHttpCode() == 500)
{
Redirect code in the link!
}
}

How to catch "null entry for parameter" error

I know there are loads of people getting this error, but most are using the built-in id functionality, of which I am not. Beyond what I've read on this site, I need to present a friendly error rather than the built in yellow screen of death:
The parameters dictionary contains a null entry for parameter 'productId'
of non-nullable type 'System.Int32'
My URL is...
/myController/myView?person=789&productId=123
...where productId should actually contain an integer value. Even though I check for it being null in the method, MVC throws the exception before the check is made.
Is it possible to catch this error and provide an Error view?
I know that I could set the variable type to be Int32? but that seems like a hack, as the method does require the value.
public ActionResult Show(string person, Int32 productId)
{
if (productId== null) // exception occurs before this point, so this check fails
{
return View("Error", new ErrorViewModel { Summary = "No value provided" });
}
// ....
}
Your question is mixed up, this is how you should code your action:
public ActionResult Show(string person, Int32? productId)
{
if (productId.HasValue == false ) // exception occurs before this point, so this check fails
{
return View("Error", new ErrorViewModel { Summary = "No value provided" });
}
// ....
}
Never will productId be null in the code you posted because no method signature could ever match a query string that had no productId in it. Now with a nullable productId your code makes sense.

Breeze throws Null reference exception when calling EntityAspect.validateProperty() method

I have the following entity property defined as the following metadata shows:
{"name":"website","dataType":"String",
"validators":[
{"name":"string"},
{"messageTemplate":"'%displayName%' is not valid",
"pattern":"^$|(^http|^https)://[a-zA-Z0-9-.]+.[a-zA-Z]{2,3}(/S*)?",
"name":"regExValidator"}]}
When I attempt to call entityAspect.validateProperty("website"), and the value of the website property is null, the call to the validateProperty() method throws the following exception:
"Unable to get property 'complexAspect' of undefined or null
reference"
I wouldn't expect this behavior since it's possible that the website entity property could be null. It looks like there may be a null reference handling bug in the validateProperty method:
In Breeze.debug.js:
proto.validateProperty = function (property, context) {
var value = this.getPropertyValue(property); // performs validations
if (value.complexAspect) { // THROWS EXCEPTION IF 'value' IS NULL
return validateTarget(value);
}
context = context || {};
context.entity = this.entity;
if (typeof(property) === 'string') {
context.property = this.entity.entityType.getProperty(property, true);
context.propertyName = property;
} else {
context.property = property;
context.propertyName = property.name;
}
return this._validateProperty(value, context);
};
Just curious if I'm doing something wrong, or if this is just a bug?
Thanks,
Richard
Edit: This was fixed in Breeze v1.3.0, available now.
This is a bug, and will be fixed in the next release, out later this week. ... and thx for finding and reporting it :)

In OpenRasta, how should you handle codec errors or exceptions?

My scenario is this:
A client application executes a HTTP POST against an endpoint exposed by OpenRasta.
The body of the request contains an error that causes a problem in the codec - which is a custom implementation of OpenRasta.Codecs.IMediaTypeReader. This converts a JSON payload to the POCO expected by the handler.
The codec throws an exception that describes the error in a useful way. For example: Newtonsoft.Json.JsonReaderException: After parsing a value an unexpected character was encountered: ". Line 4, position 5.
The client application receives a HTTP 405 - MethodNotAllowed. The client doesn't see any of the exception details.
If the codec is modified to catch a JsonReaderException and return Missing.Value, similar to the Implementing a codec wiki, then the client receives a HTTP 500 - Internal Server Error. The body of the response also describes the following exception:
System.InvalidOperationException: The operation is not ready for invocation.
at OpenRasta.OperationModel.MethodBased.MethodBasedOperation.Invoke()
at OpenRasta.OperationModel.Interceptors.OperationWithInterceptors.<Invoke>b__0()
at OpenRasta.OperationModel.Interceptors.OperationWithInterceptors.Invoke()
at OpenRasta.OperationModel.OperationExecutor.Execute(IEnumerable`1 operations)
at OpenRasta.Pipeline.Contributors.OperationInvokerContributor.ExecuteOperations(ICommunicationContext context)
at OpenRasta.Pipeline.PipelineRunner.ExecuteContributor(ICommunicationContext context, ContributorCall call)
How should I modify my application so that:
The client receives a HTTP 400 Bad Request.
The client receives a string containing the details of the exception encountered in the codec.
Here is a minor variation of the answer above - this time with codec selection based on the operation result data.
Within IConfigurationSource:
using (OpenRastaConfiguration.Manual)
{
ResourceSpace.Uses.PipelineContributor<ErrorCheckingContributor>();
ResourceSpace.Has.ResourcesOfType<ApplicationError>()
.WithoutUri
.TranscodedBy<ApplicationErrorCodec>();
// Or use a generic JSON serializer like this:
// .AsJsonDataContract();
// Other configuration here
}
Now ErrorCheckingContributor looks like this:
public class ErrorCheckingContributor : IPipelineContributor
{
public void Initialize(IPipeline pipelineRunner)
{
pipelineRunner
.Notify(CheckRequestDecoding)
.After<KnownStages.IOperationResultInvocation>()
.And.Before<KnownStages.ICodecResponseSelection>();
}
private static PipelineContinuation CheckRequestDecoding(ICommunicationContext context)
{
if (context.ServerErrors.Count == 0)
{
return PipelineContinuation.Continue;
}
Error err = context.ServerErrors[0];
// Get a suitable message (err.Message contains stack traces, so try to avoid that)
string msg = err.Title;
if (msg == null && err.Exception != null)
msg = err.Exception.Message;
if (msg == null)
msg = err.Message;
// Create instance of an error information resource which is specific for the application
// - This one is rather simple and only contains a copy of the message
ApplicationError error = new ApplicationError(msg);
// Set operation result to be "400 Bad Request" and remove errors
context.OperationResult = new OperationResult.BadRequest { ResponseResource = error };
context.ServerErrors.Clear();
// Render immediately without starting any handlers
return PipelineContinuation.RenderNow;
}
}
The class ApplicationError is:
public class ApplicationError
{
public string Message { get; set; }
public ApplicationError(string message)
{
Message = message;
}
}
At last we need a codec ApplicationErrorCodec for ApplicationError. This is not different from any other IMediaTypeWriter codec but depends a lot on your expected response media type. See https://github.com/openrasta/openrasta/wiki/Implementing-a-Codec for one example.
Having found this thread on Google Groups which contains all the answers, my current implementation looks something like this.
Within my implementation of IConfigurationSource:
using (OpenRastaConfiguration.Manual)
{
ResourceSpace.Uses.PipelineContributor<ErrorCheckingContributor>();
// Other configuration here
}
Then ErrorCheckingContributor looks something like this:
public class ErrorCheckingContributor : IPipelineContributor
{
public void Initialize(IPipeline pipelineRunner)
{
pipelineRunner
.Notify(CheckRequestDecoding)
.After<KnownStages.IOperationResultInvocation>()
.And.Before<KnownStages.ICodecResponseSelection>();
}
private static PipelineContinuation CheckRequestDecoding(ICommunicationContext context)
{
if (context.ServerErrors.Count == 0)
{
return PipelineContinuation.Continue;
}
var first = context.ServerErrors[0];
if (first.Exception is Newtonsoft.Json.JsonReaderException)
{
context.Response.Entity.ContentType = MediaType.TextPlain;
context.Response.Entity.ContentLength = first.Exception.Message.Length;
using (var sw = new StreamWriter(context.Response.Entity.Stream))
{
sw.Write(first.Exception.Message);
}
}
return PipelineContinuation.Continue;
}
}
There's some things to be aware of with the above:
If a handler were to throw a JsonReaderException, it would also be processed here.
It doesn't check what media types the client accepts. This is different from exceptions thrown by Handlers that do go through codec selection.
Tried setting context.OperationResult to context.ServerErrors - but it doesn't go through the codec.

Error Handling in ASP.NET MVC

How can I correctly handle exceptions thrown from controllers in ASP.NET MVC? The HandleError attribute seems to only process exceptions thrown by the MVC infrastructure and not exceptions thrown by my own code.
Using this web.config
<customErrors mode="On">
<error statusCode="401" redirect="/Errors/Http401" />
</customErrors>
with the following code
namespace MvcApplication1.Controllers
{
[HandleError]
public class HomeController : Controller
{
public ActionResult Index()
{
// Force a 401 exception for testing
throw new HttpException(401, "Unauthorized");
}
}
}
doesn't result in what I was hoping for. Instead I get the generic ASP.NET error page telling me to modify my web.config to see the actual error information. However, if instead of throwing an exception I return an invalid View, I get the /Shared/Views/Error.aspx page:
return View("DoesNotExist");
Throwing exceptions within a controller like I've done above seems to bypass all of the HandleError functionality, so what's the right way to create error pages and how do I play nice with the MVC infrastructure?
Controller.OnException(ExceptionContext context). Override it.
protected override void OnException(ExceptionContext filterContext)
{
// Bail if we can't do anything; app will crash.
if (filterContext == null)
return;
// since we're handling this, log to elmah
var ex = filterContext.Exception ?? new Exception("No further information exists.");
LogException(ex);
filterContext.ExceptionHandled = true;
var data = new ErrorPresentation
{
ErrorMessage = HttpUtility.HtmlEncode(ex.Message),
TheException = ex,
ShowMessage = !(filterContext.Exception == null),
ShowLink = false
};
filterContext.Result = View("ErrorPage", data);
}
Thanks to kazimanzurrashaid, here is what I wound up doing in Global.asax.cs:
protected void Application_Error()
{
Exception unhandledException = Server.GetLastError();
HttpException httpException = unhandledException as HttpException;
if (httpException == null)
{
Exception innerException = unhandledException.InnerException;
httpException = innerException as HttpException;
}
if (httpException != null)
{
int httpCode = httpException.GetHttpCode();
switch (httpCode)
{
case (int) HttpStatusCode.Unauthorized:
Response.Redirect("/Http/Error401");
break;
}
}
}
I'll be able to add more pages to the HttpContoller based on any additional HTTP error codes I need to support.
The HandleError attribute seems to only process exceptions thrown by the MVC infrastructure and not exceptions thrown by my own code.
That is just wrong. Indeed, HandleError will only "process" exceptions either thrown in your own code or in code called by your own code. In other words, only exceptions where your action is in the call stack.
The real explanation for the behavior you're seeing is the specific exception you're throwing. HandleError behaves differently with an HttpException. From the source code:
// If this is not an HTTP 500 (for example, if somebody throws an HTTP 404 from an action method),
// ignore it.
if (new HttpException(null, exception).GetHttpCode() != 500) {
return;
}
I don't think you will be able to show specific ErrorPage based upon the HttpCode with the HandleError Attribute and I would prefer to use an HttpModule for this purpose. Assuming that I have folder "ErrorPages" where different page exists for each specific error and the mapping is specifed in the web.config same as the regular web form application. And the following is the code which is used to show the error page:
public class ErrorHandler : BaseHttpModule{
public override void OnError(HttpContextBase context)
{
Exception e = context.Server.GetLastError().GetBaseException();
HttpException httpException = e as HttpException;
int statusCode = (int) HttpStatusCode.InternalServerError;
// Skip Page Not Found and Service not unavailable from logging
if (httpException != null)
{
statusCode = httpException.GetHttpCode();
if ((statusCode != (int) HttpStatusCode.NotFound) && (statusCode != (int) HttpStatusCode.ServiceUnavailable))
{
Log.Exception(e);
}
}
string redirectUrl = null;
if (context.IsCustomErrorEnabled)
{
CustomErrorsSection section = IoC.Resolve<IConfigurationManager>().GetSection<CustomErrorsSection>("system.web/customErrors");
if (section != null)
{
redirectUrl = section.DefaultRedirect;
if (httpException != null)
{
if (section.Errors.Count > 0)
{
CustomError item = section.Errors[statusCode.ToString(Constants.CurrentCulture)];
if (item != null)
{
redirectUrl = item.Redirect;
}
}
}
}
}
context.Response.Clear();
context.Response.StatusCode = statusCode;
context.Response.TrySkipIisCustomErrors = true;
context.ClearError();
if (!string.IsNullOrEmpty(redirectUrl))
{
context.Server.Transfer(redirectUrl);
}
}
}
One other possibility (not true in your case) that others reading this may be experiencing is that your error page is throwing an error itself, or is not implementing :
System.Web.Mvc.ViewPage<System.Web.Mvc.HandleErrorInfo>
If this is the case then you will get the default error page (otherwise you'd get an infinite loop because it would keep trying to send itself to your custom error page). This wasn't immediately obvious to me.
This model is the model sent to the error page. If your error page uses the same master page as the rest of your site and requires any other model information then you will need to either create your own [HandleError] type of attribute or override OnException or something.
protected override void OnException (ExceptionContext filterContext )
{
if (filterContext != null && filterContext.Exception != null)
{
filterContext.ExceptionHandled = true;
this.View("Error").ViewData["Exception"] = filterContext.Exception.Message;
this.View("Error").ExecuteResult(this.ControllerContext);
}
}
I chose the Controller.OnException() approach, which to me is the logical choice - since I've chosen ASP.NET MVC, I prefer to stay at the framework-level, and avoid messing with the underlying mechanics, if possible.
I ran into the following problem:
If the exception occurs within the view, the partial output from that view will appear on screen, together with the error-message.
I fixed this by clearing the response, before setting filterContext.Result - like this:
filterContext.HttpContext.Response.Clear(); // gets rid of any garbage
filterContext.Result = View("ErrorPage", data);
Jeff Atwood's User Friendly Exception Handling module works great for MVC. You can configure it entirely in your web.config, with no MVC project source code changes at all. However, it needs a small modification to return the original HTTP status rather than a 200 status. See this related forum post.
Basically, in Handler.vb, you can add something like:
' In the header...
Private _exHttpEx As HttpException = Nothing
' At the top of Public Sub HandleException(ByVal ex As Exception)...
HttpContext.Current.Response.StatusCode = 500
If TypeOf ex Is HttpException Then
_exHttpEx = CType(ex, HttpException)
HttpContext.Current.Response.StatusCode = _exHttpEx.GetHttpCode()
End If

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