MVC2 Validation - "A value is required" - asp.net-mvc

I have a view model with 2 properties that are optional - ie - not required. The view uses dropdownlistfor() to get values for these two fields, an includes an optionlabel of "" for the blank value.
When posted back to the create action the ModelState has an error for both of these fields saying "A value is required".
Anyone got any clue if this is a bug or a stupid user (ie, me) error?
Thanks
Udpate:
The View Model looks like this:
[DisplayName("Check Digit Type")]
public VMBarcodeMaskCheckDigitType BarcodeMaskCheckDigitType
{
get;
set;
}
[DisplayName("Mask Type")]
[Required(ErrorMessage="Mask type is required")]
public VMBarcodeMaskType BarcodeMaskType
{
get;
set;
}
[DisplayName("Product")]
public VMProduct Product
{
get;
set;
}
The binding in the controller is :
public ActionResult Create()
{
BarcodeMaskViewModel model = new BarcodeMaskViewModel(new VMBarcodeMask(), Domain.GetBarcodeMaskTypes(), Domain.GetBarcodeCheckDigitTypes(), Domain.GetProducts());
return View(model);
}
//
// POST: /Barcode/Create
[HttpPost]
public ActionResult Create(BarcodeMaskViewModel model)
{
try
{
if (ModelState.IsValid)
{
...
}
}
catch (Exception ex)
{
ModelState.AddModelError("*", ex);
}
return View(new BarcodeMaskViewModel(model.BarcodeMask, Domain.GetBarcodeMaskTypes(), Domain.GetBarcodeCheckDigitTypes(), Domain.GetProducts()));
}

I've had this problem too, and I discovered it was actually nothing to do with the optional fields.
It was because I had an auto-generating primary key column for the entity, called 'Id'. MVC2 automatically checked for a value for this, and obviously there wasn't one as it was being auto-generated.
There's an easy way to fix this is to rename the column to BarcodeId etc, rather than just Id. I gave a better explanation here: http://www.ediblecode.com/post/A-value-is-required-with-ASPNET-MVC-2.aspx
That explanation is all assuming you're using LINQ...

Just use Bind(Exclude="Id") before the first parameter of your Create action.

I think this a confirmed bug. See here: http://forums.asp.net/p/1529205/3699143.aspx

Related

Asp MVC 5 - ModelState is Invalid?

I have the following view model:
public class CreateCaseViewModel
{
[Required]
public string Subject { get; set; }
[Required]
[DisplayName("Post Content")]
[UIHint("ForumEditor"), AllowHtml]
[DataType(DataType.MultilineText)]
public string PostContent { get; set; }
// some other dropdown properties
}
The following controller action:
[HttpPost]
[ValidateAntiForgeryToken]
[ValidateInput(false)]
public ActionResult Create(CreateCaseViewModel viewModel, FormCollection collection)
{
// Re-populate dropdowns
viewModel.Categories = _unitOfWork.CategoryRepository.GetCategories();
viewModel.Subject = collection["Subject"];
viewModel.PostContent = collection["Description"];
try
{
if (ModelState.IsValid)
{
// Do stuff
}
}
catch (DataException dex )
{
throw new ApplicationException("Something :", dex);
}
return View(viewModel);
}
I am manually assigning the value to PostContent from a value in FormCollection as you can see from code above. However I still keep getting modelstate is invalid - I'm returned back to the view with the validation error saying `The Post Content field is required'
Why is modelstate invalid?
When you submit the form the model binder will read the posted request data and map it to your method parameter. After that model validation framework will do the validation. It does not look at your FormCollection for doing this. So in your case, your model validation is failing because as per your view model it is expecting a value for PostContent property and it is not available there. Your action method code where you are setting the value of it gets executed later ( by this time model validation already occurred).
Your options are, either standardize the input element name with your view model property name (rename the PostContent to Description or vice versa)
public class CreateCaseViewModel
{
[Required]
public string Subject { get; set; }
[Required]
[DisplayName("Post Content")]
[UIHint("ForumEditor"), AllowHtml]
[DataType(DataType.MultilineText)]
public string Description { get; set; }
}
Now let the model binder maps the request body to your view model parameter. Remove the manual assignment from the FormCollection in your action method
Or you can probably create a new custom model binder which does the custom mapping for you (same as what you did in your action method).
I would go with option one. Let the default model binder takes care of it.
The model is validated before it is passed to your controller action. Modifying the model does not change that.
You need to call ModelState.Clear() followed by Controller.TryValidateModel(model) to re-validate the model and reset the IsValid property.

Is it possible to update ModelState.IsValid manually?

I would like to use the built-in validation features as far as possible. I would also like to use the same model for CRUD methods.
However, as a drop down list cannot be done using the standard pattern, I have to validate it manually. In the post back method, I would like to just validate the drop down list and add this result to ModelState so that I don't have to validate all the other parameters which are done with Data Annotation. Is it possible to achieve this?
I may be mistaken about the drop down list, but from what I read, the Html object name for a drop down list cannot be the same as the property in the Model in order for the selected value to be set correctly. Is it still possible to use Data Annotation with this workaround?
Thanks.
You can use the addModelError
ModelState.AddModelError(key,message)
when you use that, it will invalidate the ModelState so isValid will return false.
Update
after seeing the comment to #Pieter's answer
If you want to exclude an element from affecting the isValid() result, you can use the ModelState.Remove(field) method before calling isValid().
Another option is to inherit IValidatableObject in your model. Implement its Validate method and you can leave all other validation in place and write whatever code you want in this method. Note: you return an empty IEnumerable<ValidationResult> to indicate there were no errors.
public class Class1 : IValidatableObject
{
public int val1 { get; set; }
public int val2 { get; set; }
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
{
var errors = new List<ValidationResult>();
if (val1 < 0)
{
errors.Add(new ValidationResult("val1 can't be negative", new List<string> { "val2" }));
}
if (val2 < 0)
{
errors.Add(new ValidationResult("val2 can't be negative", new List<string> { "val2" }));
}
return errors;
}
}
EDIT: After re-reading the question I don't think this applicable to this case, but I'm leaving the answer here in case it helps someone else.
You cannot manually set the ModelState.IsValid property but you can add messages to the ModelState that will ensure that the IsValid is false.
ModelState.AddModelError();
yes, you can achieve this (also you will use the same model for CRUD methods) :
Example MODEL
public class User
{
public virtual int Id{ get; set; }
public virtual Role Role { get; set; }
}
public class Role
{
[Required(ErrorMessage = "Id Required.")]
public virtual int Id { get; set; }
[Required(ErrorMessage = "Name Required.")]
public virtual string Name { get; set; }
}
Example VIEW with validation on the dropdownlist
#Html.DropDownListFor(m => m.Role.Id, (SelectList)ViewBag.gRoles, "-- Select --")
#Html.ValidationMessageFor(m => m.Role.Id)
CONTROLLER: clearing the required (but not needed here) fields
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Creedit(User x)
{
x.Role = db.RoseSet.Find(x.Role.Id);
if (x.Role != null)
{
ModelState["Role.Name"].Errors.Clear();
}
if (ModelState.IsValid)
{
// proceed
}
else
{
// return validation error
}
}
Might be more recent methods, since this is an old post, but this might help future readers.
One can set a field to valid with this two methods:
ModelState.ClearValidationState("Password");
ModelState.MarkFieldValid("Password");
Need to use both because the second one without the first one it gives an error stating that the state is already marked.
To set a field to invalid, just use ModelState.AddModelError() method as already referred.

Multiple Submit Buttons in MVC3 - FormCollection has no Key/Value for Input Type Submit - Remote Validation Issue?

I have the two buttons in MVC3 application.
<input type="submit" name="command" value="Transactions" />
<input type="submit" name="command" value="All Transactions" />
When I click on a button, it posts back correctly but the FormCollection has no "command" keys. I also added a property "command" in the model and its value is null when the form is posted.
public ActionResult Index(FormCollection formCollection, SearchReportsModel searchReportsModel). {
if (searchReportsModel.command == "All Transactions")
...
else
....
}
I am using IE8. How can I use multiple buttons in MVC3? Is there a workaround for this issue? I did lot of research and could not find a solution.
Update:
Dave: I tried your solution and it is throwing Http 404 error "The resource cannot be found".
Here is my code:
[HttpPost]
[AcceptSubmitType(Name = "Command", Type = "Transactions")]
public ActionResult Index(SearchReportsModel searchReportsModel)
{
return RedirectToAction("Transactions", "Reports", new { ...});
}
[HttpPost]
[ActionName("Index")]
[AcceptSubmitType(Name = "Command", Type = "All Transactions")]
public ActionResult Index_All(SearchReportsModel searchReportsModel)
{
return RedirectToAction("AllTransactions", "Reports", new { ... });
}
public class AcceptSubmitTypeAttribute : ActionMethodSelectorAttribute
{
public string Name { get; set; }
public string Type { get; set; }
public override bool IsValidForRequest(ControllerContext controllerContext, MethodInfo methodInfo)
{
return controllerContext.RequestContext.HttpContext
.Request.Form[this.Name] == this.Type;
}
}
The issue was resolved after commenting the following Remote validation attribute in the ViewModel (SearchReportsModel). It looks like it is a bug in MVC3:
//[Remote("CheckStudentNumber", "SearchReports", ErrorMessage = "No records exist for this Student Number")]
public int? StudentNumber { get; set; }
You might be able to get away with an ActionMethodSelectorAttribute attribute and override the IsValidForRequest method. You can see below this method just determines whether a particular parameter (Name) matches one of it's properties (Type). It should bind with a view model that looks like this:
public class TestViewModel
{
public string command { get; set; }
public string moreProperties { get; set; }
}
The attribute could look like this:
public class AcceptSubmitTypeAttribute : ActionMethodSelectorAttribute
{
public string Name { get; set; }
public string Type { get; set; }
public override bool IsValidForRequest(ControllerContext controllerContext, MethodInfo methodInfo)
{
return controllerContext.RequestContext.HttpContext
.Request.Form[this.Name] == this.Type;
}
}
Then, you could tag your actions with the AcceptSubmitType attribute like this:
[AcceptSubmitType(Name="command", Type="Transactions")]
public ActionResult Index(TestViewModel vm)
{
// use view model to do whatever
}
// to pseudo-override the "Index" action
[ActionName("Index")]
[AcceptSubmitType(Name="command", Type="All Transactions")]
public ActionResult Index_All(TestViewModel vm)
{
// use view model to do whatever
}
This also eliminates the need for logic in a single controller action since it seems you genuinely need two separate courses of action.
Correct me If I'm wrong, but according to W3C standard you should have only 1 submit button per form. Also having two controls with identical names is a bad idea.
when you submit (on any button) your whole page is posted back to the controller action, I have had the same problem but have not found a decent solution yet.. maybe you could work with a javascript 'onclick' method and set a hidden value to 1 for the first button and 0 for the second button or something like that?
This is a nice Blog about this found here
I like the look of adding in AcceptParameterAttribute
#CodeRush: The W3C standard does allow more than 1 submit per form. http://www.w3.org/TR/html4/interact/forms.html. "A form may contain more than one submit button".

Model Validation problem in ASP.NEt MVC 2 RC 2

I have facing the following problem after the update.
I have a Model with Class level Validation plus property level validation in it. After updating to MVC 2 RC 2. The model validation fails on Model binding. What i actually understand that new mechanism trying to validate the model when you first request it or say on GET and it get null object exception during tryvalidatemodel Model binding call.
My Model is like this below
[Serializable]
[MetadataType(typeof(InterestClaimMetaData))] //metadata with all properties level validation
//these validations fails when you request a page.
[DateComparison("DateA", "DateB", eDateComparitor.GreaterThan,
ErrorMessage = "Date A must be greater than B Date")]
[MutuallyExclusive("A", "B", ErrorMessage = "Please select either A or B field")]
public class IE {
public int ID { get; set; }
public byte[] Updated { get; set; }
}
DataComparison and MutuallyExclusive overrides the validate function isvalid and check the validation but it fails trying to validate as first requested.
dont know how to stop this happening as it should not validate model on get request; just attach the properties.
Only models without these class level validation works.
Please advise.
Thanks
Seperate your action method in your controller in to two action methods. Mark one as GET and the other as POST. Then only apply the validation in the POST method. So, for example, if you currently have an method called Create that looks something like this...
public ActionResult Create(YourModel yourModel)
{
// Some code in here to validate stuff
// Some code in here to do stuff
return RedirectToAction("Index");
}
Split this out in to two methods like this...
[HttpGet]
public ActionResult Create()
{
return View();
}
[HttpPost]
public ActionResult Create(YourModel yourModel)
{
try
{
// Some code in here to validate stuff
// Some code in here to do stuff
return RedirectToAction("Index");
}
catch
{
return View();
}
}

ASP.NET MVC: DataAnnotations - Show an error message indicating that a field must be numeric

There appears to be something of a hole in the way DataAnnotations works in that a user entering in some text into a field that will go into an int will never reach the DataAnnotations code. It kicks off a model binding error and displays the error to the user "The value 'a' is not valid for the XXXX field."
Anyway, it's all very nice that it automatically handles this situation, but I actually want to display an error message indicating the problem eg. "The value 'a' is not numeric. Please enter in a numeric value for the XXXX field".
I have tried the solutions set out How to replace the default ModelState error message in Asp.net MVC 2? and ASP.NET MVC - Custom validation message for value types, but I can't get them to work.
It appears that my resource file is not being read at all, since here (http://msdn.microsoft.com/en-us/library/system.web.mvc.defaultmodelbinder.resourceclasskey.aspx) it states "If the property is set to an invalid class key (such as a resource file that does not exist), MVC throws an exception." and even if I change the line to DefaultModelBinder.ResourceClassKey = "asdfasdhfk" there is no exception.
Anyone have any ideas?
EDIT: Here is some code. All of it is working minus my Messages.resx file's messages are not being used. The code for Messages.resx is auto generated so I won't include it.
So entering "a" into ProcessOrder results in a generic message rather than what I have entered into Messages.resx for PropertyValueInvalid (and InvalidPropertyValue for good measure).
Application_Start method
protected void Application_Start()
{
RegisterRoutes(RouteTable.Routes);
ModelBinders.Binders.DefaultBinder = new Microsoft.Web.Mvc.DataAnnotations.DataAnnotationsModelBinder(); //set dataanooations to be used
DefaultModelBinder.ResourceClassKey = "Messages"; //set data annotations to look in messages.resx for the default messages
ValidationExtensions.ResourceClassKey = "Messages";
}
Entity Class
[MetadataType(typeof(GLMetaData))]
public partial class GL
{
}
public class GLMetaData
{
public int TransRefId { get; set; }
[DisplayName("Process Order")]
public int? ProcessOrder { get; set; }
[DisplayName("Trans Type")]
[StringLength(50)]
public string TransType { get; set; }
[StringLength(100)]
public string Description { get; set; }
[DisplayName("GL Code")]
[StringLength(20)]
public string GLCode { get; set; }
[DisplayName("Agents Credit No")]
[StringLength(50)]
public string AgentsCreditNo { get; set; }
[Required]
public bool Active { get; set; }
}
Controller Action:
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Edit(GL glToBeUpdated)
{
try
{
if (!ModelState.IsValid)
return View(glToBeUpdated);
//set auto properties
glToBeUpdated.UpdateDate = DateTime.Now;
glToBeUpdated.UpdateUser = this.CurrentUser;
glDataLayer.update(glToBeUpdated);
glDataLayer.submitChanges();
return RedirectToAction("Index");
}
catch
{
glDataLayer.abortChanges();
throw;
}
}
What I did to combat a similar issue was to clear the model state, validate against ModelState["XXXX"].Value.AttemptedValue instead of against the nulled value caused by an trying to put an invalid value into the Model's property, populating the error messages and resetting the Model values.
That way I can have the error messages I want and if necessary offer more than one ("a value is required" or "the value must be numeric").
I have battled this for most of the day on MVC4 RC. No matter what i set
DefaultModelBinder.ResourceClassKey
to it never seemed to work. It also never threw an exception when I assigned junk.
This is what I was using to assign the value (to no avail):
DefaultModelBinder.ResourceClassKey = typeof(App_GlobalResources.ValidationMessages).Name;
In the end I decided to tackle this error message on the client side and override the data attribute that jQuery uses to display the message.
#Html.TextBoxFor(m => m.Amount, new Dictionary<string,object>(){{"data-val-number","Invalid Number"}})
this is working how I need it to.
Ironically this works too:
#Html.TextBoxFor(m => m.Amount, new Dictionary<string, object>() {{ "data-val-number", HttpContext.GetGlobalResourceObject("ValidationMessages", "PropertyValueInvalid") } })
Here I have taken Contact number field as string but with Range Attribute so can provide numeric validatioin to use if from your Resource file .
[Required(ErrorMessageResourceType = typeof(Global), ErrorMessageResourceName = "ContactNumberRequired")]
[Range(0, int.MaxValue, ErrorMessageResourceType = typeof(Global), ErrorMessageResourceName = "ValidContactNumber")]
[Display(Name = "Contact Number")]
public string ContactNumber { get; set; }
So now here provided ErrorMessageResourceName as key . You can customize and use it also in Multi Language

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