ASP.NET MVC

Re: Making it valid, and seeing whats not

CodeHobo — Fri, 03 Jul 2009 15:52:18 GMT

RuleViolation the class isn't part of asp.net mvc. You have to define it manually. It's mentioned in the nerd dinner tutorial that I linked to earlir. Here is the class

public class RuleViolation {
    public string ErrorMessage { get; private set; }
    public string PropertyName { get; private set; }
 
    public RuleViolation(string errorMessage, string propertyName) {
        ErrorMessage = errorMessage;
        PropertyName = propertyName;
    }
}

You can put it in the same folder as the controller, but a better location would be in the same namespace as the repository.

Re: Making it valid, and seeing whats not

Svevarn — Fri, 03 Jul 2009 11:22:40 GMT

public class RuleValidationException : Exception
    {   
        public IEnumerable<RuleViolation> RuleViolations { get; private set; }   
        public RuleValidationException(string message, IEnumerable<RuleViolation> ruleViolations)   
           : base(message)
        {   
            RuleViolations = ruleViolations;   
        }   
    }

where shall I put that? If I put it in controller I get:

Error 1 The type or namespace name 'RuleViolation' could not be found (are you missing a using directive or an assembly reference?)

Re: Making it valid, and seeing whats not

CodeHobo — Thu, 02 Jul 2009 18:32:50 GMT

The error message is just a string so you shouldn't have any problem reading it out of a resource file.

Take a look at this

http://blog.eworldui.net/post/2008/05/ASPNET-MVC---Localization.aspx

and this

http://developmentalmadness.blogspot.com/2009/05/aspnet-mvc-globalizationlocalization.html

Re: Making it valid, and seeing whats not

Svevarn — Thu, 02 Jul 2009 18:13:20 GMT

Ok, thanks, I will look into that.

Is there some easy way of making the error messages come from a resource file? (read: language-support)

Re: Making it valid, and seeing whats not

CodeHobo — Thu, 02 Jul 2009 18:04:31 GMT

Take a look at this tutorial. It shows you how to do validation
http://nerddinnerbook.s3.amazonaws.com/Part3.htm

If you follow the example there you could add the validation to your entity object (in thise case BookingObject).

Another way you can do it is directly in your SaveBookingObject, but this may not be the cleanest approach. You can do something like

public void SaveBookingObject(BookingObject bo) {  
 var violations = ValidateBooking(bo);
  if(violations.Count() > 0){
    throw new RuleViolationException("error",violations);
  }

 _repository.SaveBookingObject(bo);  
}  

public IEnumerable<RuleViolation> ValidateBooking(BookingObject bo){
  if (String.IsNullOrEmpty(bo.Property))
        yield return new RuleViolation("Property is Required","Property");

  yield break;
}

Re: Making it valid, and seeing whats not

Svevarn — Thu, 02 Jul 2009 17:53:54 GMT

At the moment I have no validation in my "service-layer", method just look like this:

 public void SaveBookingObject(BookingObject bo)
        {
            _repository.SaveBookingObject(bo);
        }

How shall I add something there and specify which fields are needed?

Re: Making it valid, and seeing whats not

CodeHobo — Thu, 02 Jul 2009 17:44:05 GMT

1) How are you doing the validation in SaveBookingObject? Depending on the validation scheme you should be able to customize which fields are required in there.

2) The way I list is all violations is to create RuleViolationException that extends Exception and adds and IEnumerable of rule violations like so

 public class RuleValidationException : Exception
    {
        public IEnumerable<RuleViolation> RuleViolations { get; private set; }
        public RuleValidationException(string message, IEnumerable<RuleViolation> ruleViolations)
            : base(message)
        {
            RuleViolations = ruleViolations;
        }
    }

In the respoistory I throw a RuleValidationException and put all the violations in there and then catch it and add it to modelstate. (you can do this either in the controller directly or in a service).

try{
      bs.SaveBookingObject(bookingobject); 
}
catch (RuleValidationException e){
     var ruleViolations = e.RuleViolations;
     foreach (var violation in ruleViolations){
       ModelState.AddError(violation.PropertyName, violation.ErrorMessage);
    }
 }

Making it valid, and seeing whats not

Svevarn — Thu, 02 Jul 2009 17:19:40 GMT

Hello

I'm trying to save using the Create action to database. I have made a form that shows some of the fields that you can edit. However it always runs the "catch" when I try to save. I dont want to fill in data to all the field in the database, just some of it.

[AcceptVerbs(HttpVerbs.Post)]
        public ActionResult CreateObject(BookingObject bookingobject)
        {
            if (ModelState.IsValid)
            {
                try
                {
                    bs.SaveBookingObject(bookingobject);
                }
                catch {
                    ModelState.AddModelError("SomeError", "errrrrrrrrror");
                }
            }

            return View("CreateObject", new BookingObjectsAdminModel { BookingObject = bookingobject });
        }

So my questions:

1) Can I specify which fields needs to be filled in in the actionmethod?

2) Can I instead of ModelState.AddError somehow list all "violations"?

Thanks in advance