ODataController erroring after return - asp.net-web-api

I have an OData service that is implemented with several MVC controllers using ODataController. I am having an issue with all but one of the controllers, where an Internal 500 error is being returned with nothing of help after my return statement:
/// <summary><see cref="ODataController" /> reacting to queries relating to <see cref="Contract" /></summary>
[CustomExceptionFilter]
public class ContractsController : ODataController
{
// GET: odata/Contracts
[EnableQuery]
public IQueryable<Contract> GetContracts()
{
return DataAccess.GetContracts();
}
... other methods
}
/// <summary>Single point of reference to access data</summary>
public static class DataAccess
{
/// <summary>Gets the queryable collection of <see cref="ContractCoverageDetail" /></summary>
/// <returns>The queryable collection of <see cref="ContractCoverageDetail" /></returns>
public static IQueryable<Contract> GetContracts()
{
IQueryable<Contract> results = null;
using (EntityFrameworkContext context = new EntityFrameworkContext())
results = context.Contracts.ToArray().AsQueryable();
return results;
}
}
Another controller using the same DataAccess class returns data just fine. All that is being returned for each other controller is:
<m:error xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">
<m:code/>
<m:message xml:lang="en-US">An error has occurred.</m:message>
</m:error>
The error appears to be raised after my return statement, and if I step through after the return (F10), I hit each individual { get; } property on the returned entity of the collection, after which a result with the above error is returned to the browser. I can't get actual error information (innererror) to appear for the life of me, and it's odd that one controller is working, while the remainder fail without any detail.
Does anyone have an Idea for what might be causing this, or how to turn on the error detail after the return statement?
GlobalConfiguration.Configuration.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;
in the global.asax.cs does not help, nor does either of the following in web.config:
<system.web>
<customErrors allowNestedErrors="true" mode="On" />
</system.web>
<system.webServer>
<httpErrors existingResponse="PassThrough" />
</system.webServer>
Any idea how I can get to the actual exception being raised?

Here's the simple guide about how to debug the Web API OData and ODL lib.
http://odata.github.io/WebApi/10-01-debug-webapi-source/

It is hard to say exactly what the cause of this issue is but here are a couple things you can try. Hopefully, one of these will get you more information on your exception.
Debugging all code
It may seem obvious but make sure that you are not debugging only your code. You can check this by accessing the debugging options under the Debug -> Options and Settings... menu. Make sure that Enable Just My Code is not checked. This might be fine usually. When there are errors with exceptions and you cant seem to get to them, sometimes this setting can mess you up
Debugging Exceptions
Another thing that can be both useful and painful at the same time are the Debug -> Exceptions... settings. These are sets of exceptions that can be configured to cause Visual Studio to automatically break allowing you to see their moving parts. For debugging MVC and .NET in general you would want to enable the Common Language Runtime Exception.
With debugging exceptions turned on, you will probably get a ton of exceptions that you wont want. Just ignore them and keep running till you get to exceptions that relate to oData.

Related

Winforms Application Fails To Launch [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 3 years ago.
Improve this question
I have a winforms application that is installed on multiple computers. Most of the time it works perfectly but for a small subset of users the application fails to launch. The only resolution I have found for this issue is to reinstall the application on the users machine.
I have included screenshots below showing the application working after a successful launch and also a screenshot showing what the user sees when the application fails
Normal Launch:
Failed Launch:
When the application fails, the startup form does not get rendered at all. On the users desktop there is nothing visible at all and the program is not outside of any visible area.
If anyone could provide answers or insight into the following questions it would be much appreciated.
What could cause this problem?
Windows or program related?
How could this be fixed?
I have included code snippets from the startup form below
Starting code:
private static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.SetUnhandledExceptionMode(UnhandledExceptionMode.CatchException);
Application.Run(new Timelord());
}
public Timelord()
{
this.InitializeComponent();
this.BringToFront();
this.Focus();
// Displays a date and gets the version of the program
lblDate.Text = DateTime.Now.ToShortDateString();
Version version = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version;
if (ApplicationDeployment.IsNetworkDeployed)
{
lblVersion.Text = string.Format("v{0}", ApplicationDeployment.CurrentDeployment.CurrentVersion.ToString(4));
}
// Loads the comboboxes for selection
this.loadComboUser();
this.loadComboCompany();
this.loadComboTick();
}
I think what is happening is that there is an error being thrown in your Timelord constructor under certain conditions. Since Timelord is the "startup" object for your application, a failure to create its instance properly would cause serious problems. Here is what I would recommend doing to identify those conditions, and to eliminate the issue with the form only being partially created.
I am assuming based on your comment about the program reading from a database that one or more of the following methods perform data access calls to a database
this.loadComboUser();
this.loadComboCompany();
this.loadComboTick();
You typically want to avoid method calls, ESPECIALLY data access calls in a constructor. There are many reasons for this that I won't list here, but this other stackoverflow article explains some of them.
Is it OK to put a database initialization call in a C# constructor?
To correct these issues, implement an eventhandler for the load event and move all of your Timelord constructor code into the Load event handler. The Form.Load event fires after the constructor is complete but before a form is displayed for the first time.
https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.form.load?view=netframework-4.7.2
Here is how I would recommend restructuring your Timelord object.
public Timelord()
{
this.InitializeComponent();
}
Private Sub Timelord_Load(sender As Object, e As EventArgs) Handles MyBase.Load
{
Try
{
this.BringToFront();
this.Focus();
// Displays a date and gets the version of the program
lblDate.Text = DateTime.Now.ToShortDateString();
Version version = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version;
if (ApplicationDeployment.IsNetworkDeployed)
{
lblVersion.Text = string.Format("v{0}", ApplicationDeployment.CurrentDeployment.CurrentVersion.ToString(4));
}
// Loads the comboboxes for selection
this.loadComboUser();
this.loadComboCompany();
this.loadComboTick();
}
Catch(Exception ex)
{
MessageBox.Show($"The following error occurred in the Timelord constructor {Environment.NewLine}{ex.Message}")
}
}
Making this change will allow the Timelord constructor to completely create the object, then the Load event will run and load any data into the UI. This way, if an error occurs, you will have at least completely created the Timelord Form and can catch the error.
What could cause this problem?
Your startup object (Timelord()) throwing an error in the constructor, therefore not properly creating object.
Windows or program related?
Program related
How could this be fixed?
Separating your Forms logic so that the only code in the constructor is your instantiation logic.
Implementing Try/Catch blocks to trap errors

EF6.1 Upgrade Issues: To SQL Server CE file Location and [NotMapped] Properties

I really appreciate any insight anyone can provide.
I've come back to a project that was using the EF6.0 rc preview. After updating the projects EF to 6.1 and updating the SQL Server CE I have two problems.
[UPDATE]
Problems 1 & 2 solved Problem 3 is not.
PROBLEM 3 -
Now with the path set via a connection string as explained above, migrations called via the package manager are not working as its an invalid path. Any ideas anyone?
When I start up the debug process, I get problem 1 and the exceptions crash; but it does create a .sdf file although in the wrong location as explained in problem 2.
1. NOT MAPPED PROPERTY AND UNSUPPORTED BY LINQ ERROR
During the initial creation process I get an exception
List<Equipment> duplicateTags = db.EquipmentReg
.GroupBy(e => e.TagAndLocation)
.Where(g => g.Count() > 1)
.SelectMany(g => g).ToList<Equipment>();
The exception is related to the TagAndLocation. TagAndLocation is defined in the model by
/// <summary>
/// Creates concatenation object that will not be mapped in the database but will be in the
/// Object Relational Mapping (ORM) of the EF model.
/// </summary>
[NotMapped]
public string TagAndLocation { get { return Tag + " (" + Location.Name + ")"; } }
A first chance exception of type 'System.NotSupportedException' occurred in EntityFramework.dll
Additional information: The specified type member 'TagAndLocation' is
not supported in LINQ to Entities. Only initializers, entity members,
and entity navigation properties are supported.
Why is this happening now?
2. CONNECTION STRING NOT APPLYING LOCATION
My connection isn't applying the path properly anymore.
I have it being done by a DbConfiguration class which auto runs, I guess due to its inherited class type. As shown below
class HAIDbJob_EFConfiguration : DbConfiguration
{
public HAIDbJob_EFConfiguration()
{
SetProviderServices(SqlCeProviderServices.ProviderInvariantName, SqlCeProviderServices.Instance);
// Create the connection string programmatically - Setting the filename and path.
SetDefaultConnectionFactory(new System.Data.Entity.Infrastructure.SqlCeConnectionFactory(
"System.Data.SqlServerCe.4.0",
System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Databases"),
#"Data Source=" + System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Databases") +
#"\Hazardous_Area_Database_Job.sdf"));
}
}
Instead of creating a file in the runtime location ...\bin\Debug\Databases\Hazardous_Area_Database_Job.sdf, it creates it at
..\bin\Debug\HA_Inspector.HAI_Database.HAI_Job_EF_Model.Hazardous_Area_Database_Job.sdf
Which is the full namespace of the database model... I have tried a few solutions found for other people problems of a slightly different nature, but none of it works. Any ideas would be extremely appreciate.
1: The EF provider attempt to translate TagAndLocation to SQL and fails. You must use LINQ to Objects for this grouping.
2: Why not have a named connectionstring in your app.config, or pass it in the DbContext constructor.
SOLUTION 1
I did a string compare in the group by statement since location has a string member Location.Name.
SOLUTION 2
When I originally wrote this I wanted to dynamically name the database all the time and this is why I wrote the initialiser class.
To get around the problem, I just followed Erik's advice and put a XAML connection string in app.config using "Source=./Databases"..... to get the subfolder.

log4net on WebApi 2.1 using ExceptionLogger

How does one properly implement WebApi 2.1's ExceptionLogger so that log4net logs the correct values for method, location and line?
What I'm trying to achieve is a global exception logger to log all unhandled exceptions in a WebAPI 2.1 v5.1.2 app running .NET 4.5.1. I've read quite a few articles including the one linked below explaining how to implement the ExceptionLogger, and it works great, except that I can't get log4net to output the values I really want to record.
For example, if I log an exception from a controller, everything is correct. When I log from the ExceptionLogger, I'm getting the values from the Logger itself, and not the method that initiated the exception. I tried a few things listed in my code below, but they're not quite right. Here's what I get.
I know the text is small, but the table shows the different values log4net writes. The first log is from the controller, everything is great. The 2nd entry is from log.Logger.Log in the code snippet. The last entry is from log.Error in the snippet.
The final method in the snippet attempts to use a limiting type as I've read from other implementations of log4net wrappers, but it just throws an error, as described in the snippet.
So, HOW CAN I GET THE VALUES LIKE THE ONES I WOULD RECEIVE IF CALLING FROM A CONTROLLER, WHEN USING A GLOBAL ExceptionLogger ?
public class GlobalExceptionLogger: ExceptionLogger
{
//private static readonly ILog log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
public override void Log(ExceptionLoggerContext context)
{
StackTrace stackTrace = new StackTrace(context.Exception);
Type methodDeclaringType = stackTrace.GetFrame(2).GetMethod().DeclaringType;
ILog log = LogManager.GetLogger(methodDeclaringType);
string message = context.ExceptionContext.Exception.Message;
//this methods works but writes the location, method name and line from this method, not the caller
//location: System.Web.Http.ExceptionHandling.ExceptionLogger.LogAsync(:0)
//method: LogAsync
//line: 0
log.Logger.Log(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType, log4net.Core.Level.Error, message, context.ExceptionContext.Exception);
//this methods works but writes the location, method name and line from this method, not the caller
//location: Company.AppName.Api.GlobalExceptionLogger.Log(c:\TFS\AppName\AppName.Api\GlobalExceptionLogger.cs:38)
//method: Log
//line: 38
log.Error(message, context.ExceptionContext.Exception);
//this method throws an error in the log4net debug: log4net:ERROR loggingEvent.LocationInformation.StackFrames was null or empty.
log.Logger.Log(methodDeclaringType, log4net.Core.Level.Error, message, context.ExceptionContext.Exception);
}
}
http://weblogs.asp.net/jongalloway//looking-at-asp-net-mvc-5-1-and-web-api-2-1-part-4-web-api-help-pages-bson-and-global-error-handling
Your method of getting the stacktrace is not recommended, because the code will behave differently on debug/release or precessor architecture. The method stackTrace.GetFrame(2).GetMethod() will give you the method on the real stack, with taking into consideration the optimalizations of the runtime for processor architecture, linq rewrites etc.
An alternative method of getting the member name:
public static string LogError(Exception ex, [CallerMemberName] string callerName = "")
You should have a look at this question:
stackframe-behaving-differently-in-release-mode

How do I add a script bundle conditionally?

I have a javascript bundle that I only want to include when testing, not when the code is deployed to production.
I have added a Property called IsEnabledTestingFeatures. In the BundleConfig.cs file I access it like so:
if(Properties.Settings.Default.IsEnabledTestingFeatures) {
bundles.Add(new ScriptBundle("~/bundles/testing").Include("~/Scripts/set-date.js"));
}
This works correctly.
Now, I only want to include the bundle in my page if this property is set to true.
I have tried the following, but the compiler is complaining that it cannot find the Default namespace:
#{
if( [PROJECT NAMESPACE].Properties.Default.IsEnabledTestingFeatures)
{
#Scripts.Render("~/bundles/testing")
}
}
I tried finding how to access the Scripts.Render functionality from the Controller itself, but have been unsuccessful.
I prefer to add the bundle in the view itself, but will settle for adding it via the Controller.
The ViewBag should not be necessary...
Using appSettings from web.config you don't need to recompile for testing and it deploys easily.
<appSettings>
<add key="TestingEnabled" value="true" />
</appSettings>
View or Layout
#{
bool testing = Convert.ToBoolean(
System.Configuration.ConfigurationManager.AppSettings["TestingEnabled"]);
}
#if (testing) {
#Scripts.Render("~/bundles/testing")
}
And I would define "~/bundles/testing" in BundleConfig regardless of the testing condition unless you wish to bundle this with other scripts.
If you assigned Properties.Default.IsEnabledTestingFeatures from AppSettings then the root of your problem is how you implemented your Properties.
Until, hopefully, an alternative [read: better] solution is proposed, I have implemented it using ViewBag.
BundleConfig.cs
//if testing features are enabled (eg: "Set Date"), include the necessary scripts
if(Properties.Settings.Default.IsEnabledTestingFeatures)
{
bundles.Add(new ScriptBundle("~/bundles/testing").Include(
"~/Scripts/set-date.js"));
}
Controller
public ActionResult Index()
{
ViewBag.IsEnabledTestingFeatures = Properties.Settings.Default.IsEnabledTestingFeatures;
return View();
}
View
#if (ViewBag.IsEnabledTestingFeatures != null && ViewBag.IsEnabledTestingFeatures)
{
#Scripts.Render("~/bundles/site")
}
Some Notes:
I did not implement this via a property in the ViewModel due to this
property/feature being independent of the data being displayed. It
seemed incorrect to associate this condition with individual data
models as it is a site-wide feature.
I used application-level settings because it will be easier to configure this property on a per-environment basis due to the fact we utilize web transforms. Thus each environment can set this property as needed.

Is there a way to prevent Visual Studio from breaking on exceptions in a specific method?

I know I can control the way Visual Studio handles exceptions according to their type and to the fact that they're eventually caught using the "Exception" dialog.
However, I've got a library that's internally throwing (and catching) an ArgumentOutOfRange exception when I'm calling a specific method. The exception is thrown (and caught by the library) maybe 1% of the time, but I'm calling this method a lot. The editor says it's by design (and indeed, the design they've chosen makes sense).
The thing is that I don't want Visual Studio to break each time the exception is thrown.
I don't want to stop breaking on ArgumentOutOfRange exceptions, as I may have some in my code and want to break on those.
I don't want to enable "just my code" debugging because I'm concerned about the exceptions thrown outside of my code (notably for performance reasons)
Is there a way to achieve this? I've been looking into attributes (such as DebuggerStepThrough), but haven't find something adequate yet.
Any hints on how to do this ?
I don't want to enable "just my code" debugging
Yeah, stop there right now. That is exactly the feature you need to not get the unwanted debugger breaks. If you don't want to know about somebody else's crappy code then flip that checkbox back on.
This invariably goes off the rails when programmers use exceptions for flow control. A very common crime. It takes two of them to turn that into a mess that turns a debugging session into a very tedious click nightmare. When you need the debugger feature that breaks on the first-chance exception then you basically lost if somebody else needed that as well.
Everybody hopes that they can magically use the [DebuggerNonUserCode] or [DebuggerHidden] or [DebuggerStepThrough] attributes to make that problem disappear. It doesn't. The other programmer did not think his code was unimportant enough to deserve those attributes. And, well, it wasn't because there's always a bug hidden in code that uses try/catch-em-all code. Pokémon code.
So Microsoft had to find another way to help programmers deal with crappy library code. They did. Tick that checkbox, bam, solved. Nothing you can do about that crappy code anyway, other than sending a nasty-gram to the author. Don't let us or Microsoft slow you down doing that as well, y'all have to get along to create a product that people like to use.
I think it's not possible in visual studio but it certainly is in WinDbg.
See for example http://blogs.msdn.com/b/alejacma/archive/2009/08/24/managed-debugging-with-windbg-breaking-on-an-exception-part-1.aspx
On a side note it seems that starting with visual studio 2010 you can load and use WinDbg extension DLLs directly providing aditional functionality (including possibly the one that you need) but I haven't tried this yet - see for example http://www.dotnetcurry.com/ShowArticle.aspx?ID=648
What you can do is use Concord, the debug engine that ships with Visual Studio (starting with version 2012). It's quite extensible through a nice managed API (and deployable using vsix technology), but it's not fully documented.
Concord has the concept of debug monitors, that we can hook using the IDkmDebugMonitorExceptionNotification Interface
The cool thing is this interface can monitor all exceptions thrown. It can also "suppress" any detected exception event, which is exactly what we need.
What I suggest is to start with the Hello World sample: . Download it, and make sure it runs as expected for you.
Now, just modify HelloWorld.vsdconfigxml like this:
<!--TODO: If you copy the sample, ensure to regenerate the GUID in this file -->
<!-- 1. change component level to something higher than 40500 -->
<ManagedComponent
ComponentId="51736b11-9fb4-4b6d-8aca-a10a2b7ae768"
ComponentLevel="40501"
AssemblyName="HelloWorld">
<!-- 2. change class full name to HelloWorld.ExceptionHandler, for example -->
<Class Name="HelloWorld.ExceptionHandler">
<Implements>
<InterfaceGroup>
<NoFilter/>
<!-- 3. change supported interface -->
<Interface Name="IDkmDebugMonitorExceptionNotification"/>
</InterfaceGroup>
</Implements>
</Class>
</ManagedComponent>
Then, just create an ExceptionHandler.cs class and put something like this in there:
public class ExceptionHandler : IDkmDebugMonitorExceptionNotification
{
private bool _unhandledDetected;
// we're being called!
public void OnDebugMonitorException(DkmExceptionInformation exception, DkmWorkList workList, DkmEventDescriptorS eventDescriptor)
{
if (_unhandledDetected)
{
// this will cause the program to terminate
eventDescriptor.Suppress();
return;
}
if (exception.ProcessingStage.HasFlag(DkmExceptionProcessingStage.Unhandled))
{
_unhandledDetected = true;
}
else if (exception.ProcessingStage.HasFlag(DkmExceptionProcessingStage.Thrown))
{
if (SuppressException(exception))
{
eventDescriptor.Suppress();
}
}
}
// should we suppress a thrown (1st chance) exception?
private bool SuppressException(DkmExceptionInformation exception)
{
// implement any custom logic in here, for example use the exception's name
if (exception.Name == typeof(ArgumentOutOfRangeException).FullName)
{
// for example, use the module (assembly) name
var clrAddress = (DkmClrInstructionAddress)exception.InstructionAddress;
var clrModule = clrAddress.ModuleInstance;
if (clrModule.Name == "TheUglyOne.dll")
return true; // we don't want this one!
}
return false;
}
}
When you run the project, you should see all exceptions being monitored (regardless of your 'just my code' and/or exception triggers settings), so what you just need to do is implement some logic to suppress the ones you really don't want to see. I've not checked but I suppose you could build your logic using custom attributes as the Dkm classes provide quite a lot of .NET metadata information.
Note: as you can see, there is some trickery to make sure the program will terminate normally.

Resources