AtEase.AspNetCore.Extensions.Middleware

Installation:

execute the command in Nuget package manager console:

PM> Install-Package AtEase.AspNetCore.Extensions.Middleware

Argument Exceptions:

For handling argument exceptions add app.UseWebApiErrorHandling(config);

    public void Configure(IApplicationBuilder app ...)
    {	var config = new WebApiErrorHandlingConfig();
	    
		config.CatchArgumentNullException();
		config.CatchArgumentOutOfRangeException();
		config.CatchArgumentException();
		...
		CatchAllArgumentsExceptions(); // Catch all argument exceptions
	    
	    app.UseWebApiErrorHandling(config);
	    ...
    }

Custom Exceptions:

For handling custom exceptions there is two way

• Use attributes
• Use Mapper

  Use this to not refrence infrastructure in domain model

Use Attributes

For handling custom exceptions with attributes add app.UseWebApiErrorHandling();

    public void Configure(IApplicationBuilder app ...)
    {
	    app.UseWebApiErrorHandling();
	    ...
    }

And add following attributes

• Api Validation Exception:

  Handling exceptions (e.g validation errors) that raised in the services and return BadRequest (400) HttpStatus with custom message. if the message argument left blank, the message value is taken from the Exception. Add WebApiBadRequest attribute to your exceptionclass:

      [WebApiBadRequest("Name", "Name must has our pattern.")]
      public class NameValidationException : Exception
      {
      }

  Web API result must be same as Web API BadRequest result.

• Api Exception:

  Handling exceptions (e.g conflict errors) that raised in the services and return Conflict (409) HttpStatus with custom message. Add WebApiConflict attribute to your exception class: if the message argument left blank, the message value is taken from the Exception.

      [WebApiConflict(2001, "the Invoice accepted in the past!!")]
      public class InvoiceAcceptedInThePastException : Exception
      {
      }

Web API result must be same as Web API Conflict result.

Use Mapper

Create new Mapper:

	public class WebApiErrorHandlingConflictExceptionMapper : WebApiErrorHandlingConflictMapper  // mapping conflicts
    {
        public override bool CanHandle(Exception exception)
        {
            return exception.GetType() == typeof(WebApiErrorHandlingConflictException); // Can handle new type of exceptions
        }

        public override object CreateContent(Exception exception)
        {
            var ex = (WebApiErrorHandlingConflictException) exception;

            if (ex.ErrorCode.IsNotNull())
            {
                return new ConflictObjectResult(CreateModelState(ex.ErrorCode.Value.ToString(),
                                                                 ex.Message));
            }

            if (ex.Message.IsNotNullOrEmpty())
            {
                return new ConflictObjectResult(ex.Message);
            }

            return new ConflictResult();
        }
    }

And config should be like this:

    public void Configure(IApplicationBuilder app ...)
    {	var config = new WebApiErrorHandlingConfig();
	    
		config.Map(new WebApiErrorHandlingConflictExceptionMapper());
	    
	    app.UseWebApiErrorHandling(config);
	    ...
    }

And web API result must be same as Web API Conflict result.