Exception Handling In MVC [Top 2 Methods To Handle Exception]

Exception handling in MVC is majorly used when creating line-of-business applications that require particular specifications and conditions and have unique requirements. 

Let’s understand what exception handling is in-depth and how it helps you with your applications. 

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What Is Exception Handling?

It is the process of handling and responding to exceptional conditions that occur and require specific methods; this needs to be incorporated in business applications to enhance the outcome and ensure that all requirements are properly handled. 

There are two significant ways in which these exceptions are handled

• The catch and block method
• The application error handling method.

However, these are not the only methods used for the process. 

Here, we will discuss the different steps and techniques you can use to manage exceptions in MVC.  

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The Try-Catch Handling Method

The catch and block method is considered the traditional method used for exception handling in MVC based applications. You will be logging the error information using this method.

Try 

{ add an exception;}

catch (exception name)

{

return View (“Error”);

}

You enter the exception condition in the try blog and add the exception name for the catch block. When the exception is caught in the catch block, it will return the error that it mentions.

This can also be used to handle and log all the errors within the application.

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OnException Method 

This method allows you to override the OnException method within the controller class. The error code 500 is used to handle all the logged errors resulting from the exception handling in MVC.

Basically, you can log and specify the exception’s view with this method without the try loop. You need not enable the <customErrors> config in the web.config to get started with this method. 

public class HomeController: Controller

{

    public ActionResult Contact()

    {

        string msg = null;

        ViewBag.Message = msg.Length;     

        return View();

    }

    protected override void OnException(ExceptionContext filterContext)

    {

        filterContext.ExceptionHandled = true;

        //Log the error!!

        //Redirect to action

        filterContext.Result = RedirectToAction(“Error”, “InternalError”);

        // OR return specific view

        filterContext.Result = new ViewResult

        {

            ViewName = “~/Views/Error/InternalError.cshtml”

        };

   }

}

Take a look at the code above, and you will notice that OnException is a void method, and it takes the object ExceptionContext as the argument.

This argument contains all the information required to log the error. If you set ExceptionHandled=true, then you will be able to log the actions generated from a particular controller with ease.

HandleError Attribute

This is yet another popular method of handling the exception and managing errors within the MVC of your application. If you notice errors created by an action method or a controller, you should use this method.

With this attribute, you can select to display a custom view for the particular exception. This could occur either in the action method or the controller.

Again, this method is also used when you are managing errors with code 500. You cannot log exceptions using this method.

There is a particular way to add this attribute for it to work at your behest. You should add the HandleError attribute filter inside the FilterConfig.RegisterGlobalFilters() method.

Along with this, you should ensure that the <CustomErrors mode = “on”> custom errors mode is always set to on within the web.config. At this point, you can add the attribute to the active mode. 

public class HomeController: Controller

{

    [HandleError]

    public ActionResult Contact()

    {

        string msg = null;

        ViewBag.Message = msg.Length; 

        return View();

    }

}

The code we just mentioned works best for the context and exception handling needs.

Here the attribute is configured for the Contact() action method. When the process is compiled, you will see the Error.cshtml displayed in the view mode. 

This will occur only when an exception occurs. This is the default view in all exceptional cases. You can also use this attribute to configure the various pages to manage the different types of exceptions. 

While this attribute works perfectly for error handling and manages all types of configurations, it may not work everywhere. Choose it for some instances where you believe it will help your application. 

The method does not support the logging exceptions. It manages to capture only HTTP exceptions within code 500. It cannot capture the exceptions from other controllers. So, it is not an attribute that you can consider for all occasions and needs.

Inheriting From HandleError

You can even use this method to handle exceptions. The above method that we discussed doesn’t allow you to reuse the components, which can be considered a drawback. 

You cannot function if you have to keep coding for all the exceptions that need to be logged. 

As a result, you will have to use this extension. It allows you to inherit from the HandleError attribute, and use it across the specific controller. As a result, you can handle exceptions without having to code too often. 

Also Read: Exception Handling Interview Questions

Application_Error Event 

Application_Error Event is yet another method of handling the Application error and managing the exceptions. This part requires you to control the Application_Error event within the global.asax file. 

You can trigger this event for all types of error codes and exception handling in MVC, making it easier to use and one of the best methods to handle exceptions.

This uses the primary error logging method, which can be used to manage all exceptions that are not handled within the application. 

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Managing HTTP Errors

The method mentioned here cannot handle any of the HTTP exceptions. We are talking about exceptions such as “File Not Found” and other such common error messages that you are bound to get.

You will need to enter the error details and the error code within the syntax to manage these exceptions. 

You will need to note all the possible error codes and messages that you are likely to get as part of the application before you release the syntax.

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Conclusion 

When dealing with exception handling in MVC, you need to make sure that the method you are opting for allows you to record all the possible errors. You should be able to reuse the components and manage all application errors. Learn about exception handling in Java.

If you want a single method to handle all possible exceptions, you should opt for the Global Application_Error method. It makes sure to log all errors along with the <CustomErrors> and ensures that they are recorded on the Web.Config.

With this method, the user is redirected to the specific pages when they encounter the error. Exception handling is one of the core concepts of application development using ASP.Net MVC. 

We hope this article was insightful to learn about Exception Handling in MVC; please explore our blogs to know more about different applications.

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