Strange error: No parameterless constructor defined for this object - c#

I know this has been asked many times but I can't solve my problem which is very funny.
My model is simple:
public class RegisterModel
{
[Display(Name = "First name")]
[Required]
public string FirstName { get; set; }
[Display(Name = "Last name")]
[Required]
public string LastName { get; set; }
[Display(Name = "Email address")]
[RegularExpression(#"^([a-zA-Z0-9_\-\.]+)#((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$", ErrorMessage = "Enter valid e-mail")]
[Required(ErrorMessage = "E-mail is empty")]
public string EmailAddress { get; set; }
public System.Web.Mvc.SelectList Countries { get; set; }
}
Action:
[AllowAnonymous]
public virtual ActionResult Register(RegisterModel data)
{
if (!HttpContext.User.Identity.IsAuthenticated)
{
ModelState.Clear();
var countries =
this.ClientRepositoryBuilder
.CountryClientRepository
.GetAllCountries();
data.Countries = new SelectList(countries, "Id", "CountryName");
return
this.View(data);
}
else
{
return
this.RedirectToAction(MVC.Home.Index());
}
}
As soon as I add Countries into my model, stuff stops working and it doesn't invoke POST Action, give me an error with firebug(it's ajax post):
No parameterless constructor defined for this object

Default Model binding can't deal with that object when trying to convert from information coming in request to RegisterModel.
Options:
separate "incoming request model" from "view model" (as it looks like you always setting that property in controller).
create custom model binding - check more MSDN: The Features and Foibles of ASP.NET MVC Model Binding, or SO When to use IModelBinder versus DefaultModelBinder.
If you want something like accepting list as request parameter - Model Binding to a List MVC 4 may have an answer.

Ok I did a mistake with type, don't even know how I did this mistake.. So I updated model with proper type for Countries and stuff works now:
[Required]
public int Countries { get; set; }
It was a mistake due mine tiredness ;)

Related

Skip Model validation at action level in MVC

I have an action method which outputs a model which has multiple sub models. In one of the sub model I have some additional properties which are not required in my view.
Sub model- ProjectModel-
[Required(ErrorMessage = "*")]
public int Id { get; set; }
[Required(ErrorMessage = "*")]
public int SectorDivisionId { get; set; }
[Required(ErrorMessage = "*")]
[StringLength(250, ErrorMessage = "Project name should not be more than 250 characters.")]
public string Program { get; set; }
[Required(ErrorMessage = "*")]
[StringLength(25, ErrorMessage = "Project number should not be more than 25 characters.")]
public string ProjectNumber { get; set; }
public string WorkPackage { get; set; }
public string WorkPackageType { get; set; }
[Required(ErrorMessage = "*")]
public DateTime StartDate { get; set; }
[Required(ErrorMessage = "*")]
public DateTime EndDate { get; set; }
public int ProjectDirectorId { get; set; }
So while initializing the sub model to my main model I am only using those properties which I need as shown below.
model.ProjectInfo = new ProjectModel()
{
Id = projectId,
ProjectNumber = prj.p.ProjectNumber,
Director = prj.Director,
Program = prj.p.Program,
StartDate = prj.p.StartDate,
EndDate = prj.p.EndDate,
ProjectReviewPeriodList = projectReviewPeriodList.AsEnumerable().
Select(o => new ProjectReviewPeriodModel
{
Id = o.Id,
ProjectReviewTypeId = o.ProjectReviewTypeId,
ProjectId = o.ProjectId,
ReviewPeriod = o.ReviewPeriod,
ReviewPeriodDate = o.ReviewPeriodDate
}).ToList()
};
Now, while posting the form I have an action filter at global level which validates the Model. The validation (ModelState.IsValid) fails for some of the fields from the sub model which I haven't initialized as per my needs.
I thought of two options-
Using ModelState.Remove(<PropertyName>) to skip validation. This is not possible as I am using a global level action filter.
Create a new view model
Is there any other way of doing this, preferably in the action method level?
Please let me know if any doubts or I can explain it more clearly.
Thanks.
The clean way would be to use different ViewModels for different usecases.
That being said, you can implement the validation logic with IValidatableObject instead of using Data Annotations attributes.
Introduce a flag into the ViewModel that indicates the usecase, e.g. IsEditUsecase. Set this flag somewhere where you know the usecase, e.g. in the controller.
Then only perform the validations that are needed for this usecase.
public class ProjectModel : IValidatableObject {
public bool IsEditUsecase { get; set; }
[Required(ErrorMessage = "*")] // required for every usecase
public int Id { get; set; }
// no [Required] and [StringLength] attributes
// because only required in some of the usecases
public string Program { get; set; }
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext) {
// validation that occurs only in Edit usecase
if (IsEditUsecase) {
// Validate "Program" property
if (string.IsNullOrWhiteSpace(Program)) {
yield return new ValidationResult(
"Program is required",
new[] { "Program" }
);
}
else if (Program.Length > 250) {
yield return new ValidationResult(
"Project name should not be more than 250 characters.",
new[] { "Program" }
);
}
// validate other properties for Edit usecase ...
}
// validate other usecases ...
}
}
As a dirty hack, I have added hidden fields in my razor page for all those properties which caused ModelState validation error. Basically I added some default values for the hidden fields and it works fine now.
Not recommended though but it was a quick fix.

C# Passing params to another view

I have a set up where a Company can have none or one or many clients. So there is no strict relationship between the Client table and the Company table. I have created a Search view where all companies are populated. Then using a button a client can be attached to the company. I thought using an ActionLink I would be able to achieve this, so my Search (view) has,
#Html.ActionLink("Book", "Book", new { id = a.CompanyId })
Where the Model is looped over to get all the company list. Now when I click the link, it populates the Address with the right params, Companies/Book/1 the ID I am playing with is 1. Which is correct, however the View I am landing at is a new Customer Model.
public class CustomerModel
{
[HiddenInput(DisplayValue = true)]
public long CompanyId { get; set; }
[HiddenInput(DisplayValue = false)]
public long CustomerId { get; set; }
[Display(Name = "Customer Name")]
[Required(ErrorMessage = "* required")]
public string CustomerName { get; set; }
[Display(Name = "Address Line 1")]
[Required(ErrorMessage = "* required")]
public string AddressLine1 { get; set; }
[Display(Name = "Postcode")]
[Required(ErrorMessage = "* required")]
public string Postcode { get; set; }
[Display(Name = "Phone Number")]
[Required(ErrorMessage = "* required")]
[RegularExpression(#"\d*", ErrorMessage = "Not a valid phone number")]
public string PhoneNo { get; set; }
}
Even though I am able to see the ID being passed (using FireBug) is 1, somehow when I click the button to submit the view to the controller I get a 0. Why would this be? Could anyone help me?
EDIT - 1
This is the controller.
public ActionResult Book()
{
return View(new CustomerModel());
}
[HttpPost]
public ActionResult SaveCustomer(CustomerModel model)
{
_companyService.SaveCustomer(model);
return RedirectToAction("Index");
}
I have tried using the CompanyId instead of id, it came up with another error.
Before submitting the Form, Address bar has : http://localhost:53294/Companies/Book?CompanyId=1
After submitting the Form, Address Bar has : http://localhost:53294/Companies/SaveCustomer
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_dbo.Customer_dbo.Company_CompanyId". The conflict occurred in database "BoilerServicing", table "dbo.Company", column 'CompanyId'.
The statement has been terminated.
The save method by itself,
public void SaveCustomer(CustomerModel customer)
{
using (var db = new BoilerServicingDbContext())
{
Customer entity;
if (customer.CustomerId > 0)
{
entity = db.Customers.First(x => x.Id == customer.CustomerId);
}
else
{
entity = new Customer();
db.Customers.Add(entity);
}
entity.Name = customer.CustomerName;
entity.TelephoneNumber = customer.PhoneNo;
entity.AddressLine1 = customer.AddressLine1;
entity.PostCode = customer.Postcode;
entity.CompanyId = customer.CompanyId;
db.SaveChanges();
}
}
Okay, after trying so many ways, I have come to this. I changed the Action method on the controller.
public ActionResult Book(long id)
{
return View(new CustomerModel
{
CompanyId = id
});
}
This seems to have passed in the CompanyId I am passing into the Book view. Took me a while, but I got there. Thanks for all your help !

Passing a variable to validator

I am trying to set-up a remote validation similar to the one in this example:
Example
My application has a twist however, my form elements are dynamically generated, therefore this tag:
[Remote("doesUserNameExist", "Account", HttpMethod = "POST", ErrorMessage = "User name already exists. Please enter a different user name.")]
is not set in stone, I need to vary the ErrorMessage for example and preferably vary the action. Is it possible, or would you suggest taking the long-way, meaning to implement the whole ajax validation on my own.
Any suggestions are appreciated.
If you need to have a dynamic error message then you could return this as string from your validation action:
public ActionResult DoesUserNameExist(string username)
{
if (Exists(uasername))
{
string errorMessage = "Some dynamic error message";
return Json(errorMessage, JsonRequestBehavior.AllowGet);
}
return Json(true, JsonRequestBehavior.AllowGet);
}
And if you need even more flexibility such as invoking dynamic dynamic actions, then you're better of rolling your custom validation solution instead of relying on the built-in Remote attribute.
You can inherit from RemoteAttribute and make it fetch the required values from a service or factory according to your own logic. Here is an example:
[AttributeUsage(AttributeTargets.Property)]
public class MyRemoteAttribute : RemoteAttribute
{
public MyRemoteAttribute(Type type, string propertyName)
: base(MyRemoteAttributeDataProvider.GetAttributeData(type,propertyName).Action, MyRemoteAttributeDataProvider.GetAttributeData(type,propertyName).Controller)
{
var data = MyRemoteAttributeDataProvider.GetAttributeData(type,propertyName);
base.ErrorMessage = data.ErrorMessage;
base.HttpMethod = data.HttpMethod;
}
}
public static class MyRemoteAttributeDataProvider
{
public static RemoteAttributeData GetAttributeData(Type type
, string propertyName)
{
//this is where you are going to implement your logic im just implementing as an example
//you can pass in a different type to get your values. For example you can pass in a service to get required values.
//property specific logic here, again im going to implement to make this
//specification by example
var attrData = new RemoteAttributeData();
if(propertyName == "MyOtherProperty")
{
attrData.Action = "MyOtherPropertyRelatedAction";
attrData.Controller = "MyOtherPropertyRelatedController";
attrData.ErrorMessage = "MyOtherPropertyRelated Error Message";
attrData.HttpMethod = "POST";
}
else
{
attrData.Action = "UserNameExists";
attrData.Controller = "AccountController";
attrData.ErrorMessage = "Some Error Message";
attrData.HttpMethod = "POST";
}
return attrData;
}
}
public class RemoteAttributeData
{
public string Controller { get; set; }
public string Action { get; set; }
public string HttpMethod { get; set; }
public string ErrorMessage { get; set; }
}
And this is how you are supposed to use is:
public class RegisterViewModel
{
[Required]
[Display(Name = "User name")]
[MyRemote(typeof(RegisterViewModel),"UserName")]
public string UserName { get; set; }
[Required]
[StringLength(100, ErrorMessage = "The {0} must be at least {2} characters long.", MinimumLength = 6)]
[DataType(DataType.Password)]
[Display(Name = "Password")]
public string Password { get; set; }
[DataType(DataType.Password)]
[Display(Name = "Confirm password")]
[System.ComponentModel.DataAnnotations.Compare("Password", ErrorMessage = "The password and confirmation password do not match.")]
public string ConfirmPassword { get; set; }
[Required]
[MyRemote(typeof(RegisterViewModel),"MyOtherProperty")]
public string MyOtherProperty { get; set; }
}
As I also mentioned above at the commentary. You should specialize that provider according to your needs.
I hope this helps.
UPDATE:
I update the implementation based on your comment, so that it takes a property name and does some property name specific wiring.

#Html.DropDownListFor fails in partial view but not in Full Page View

I am having an issue where my PartialView DropDownListFor gets the error:
The ViewData item that has the key PlanId is of type System.int32 but must be of type
IEnumerable<SelectListItem>
#Html.DropDownListFor(model => model.PlanId, (SelectList)ViewBar.PlanNameSelectList, new {#class = "short" })
This error does not pop up when I go to the page that originally held this code. What I have done is gutted the core part of the code which has worked previously with another partialView, as long as I took out the DropDownListFor elements in the code. I did not need them for that partialView, but now that I need them the problem has come full circle.
I would greatly appreciate any help that can be given to me to help solve this problem. Other resources like calls to the partial are below
#Html.Partial("location", new MAO.Models.ViewModels.CreateTemplateModel{})
This is the model
public class CreateTemplateModel {
[Required(ErrorMessage = "{0} is required.")]
[RegularExpression("^[0-9]+$", ErrorMessage="Template Id can only contain numbers")]
[Display(Name = "Template ID")]
public string TNumber { get; set; }
[Required(ErrorMessage = "{0} is required.")]
[RegularExpression("^.[0-9]{4}(-[0-9]{3})?$", ErrorMessage = "H# Must follow either #XXXX or #XXXX-XXX pattern")]
[Display(Name = "HNumber")]
public string HNumber { get; set; }
[RequiredIfOtherIsEmpty("NewPlanName", ErrorMessage = "Please enter a Plan Name")]
[Display(Name = "Select Existing Plan Name")]
public int PlanId { get; set; }
[MaxLength(500, ErrorMessage="{0} can't be longer than 500 characters")]
[Display(Name = "Enter New Plan Name")]
public string NewPlanName { get; set; }
[RequiredIfOtherIsEmpty("NewParentOrganization", ErrorMessage = "Please enter a Parent Organization")]
[Display(Name = "Select Existing Parent Organization")]
public string ParentOrganization { get; set; }
[MaxLength(500, ErrorMessage = "{0} can't be longer than 500 characters")]
[Display(Name = "Enter New Parent Organization")]
public string NewParentOrganization { get; set; }
[Required(ErrorMessage = "{0} is required.")]
public int TemplateTypeId { get; set; }
}
There is a controller that is pretty long so I am not going to post that. If there are parts of the controller that would be helpful I can post those parts as well as anything else that I might have forgotten to include
Based on your comments, I'm suspecting that you're never rebinding your drop down list when you are returning your partial view. Your controller action for the partial should be building your dropdown list in an identical manner to the controller action that renders the full view. Compare the two and make sure that they match.
UPDATE: Your partial view action should look something like the following:
public ActionResult Location()
{
ViewBag.PlanNameSelectList = new SelectList(plans.Distinct(), "Id", "Name", plans.FirstOrDefault(plan => plan.Name == selectedPlan));
attachSelectLists(ViewBag);
return PartialView("Location");
}
What you are currently doing with
#Html.Partial("location", new MAO.Models.ViewModels.CreateTemplateModel{})
Is rendering the partial view "location" using a NEW CreateTemplateModel object, not an existing one. Instead, a better way to do it is to duplicate your controller actions. Create a new one specifically for your partial view (this is a simpler use case for now).
public ActonResult TestPartialView()
Instead of using #Html.Partial which renders a partial, try calling your new controller action instead, which will build your drop down list for you.
#Html.RenderAction("TestPartialView").
This will call your new controller action and render the partial on the page, preserving the controller logic. If you use #Html.Partial, it simply renders the partial view passing in whatever object you give it which, in this case, is a new, empty CreateTemplateModel.

MVC unique HTML IDs with helpers

New to MVC
The model is a list of:
public class person
{
[Display(Name = "ID")]
public object personID{ set; get; }
[Display(Name = "Last Name")]
public object personLastName { set; get; }
[Display(Name = "First Name")]
public object personFirstName{ set; get; }
}
On the view:
#model = List<person>
foreach(person member in Model)
{
Html.LabelFor(member.personLastName)
Html.EditorFor(member.personLastName)
etc.
Each Label will focus on the first editor, I'm assuming due to all the IDs being the same.
Passing the id as "fieldname + id" in each helper works, but is tedious, is there any easy way of creating ids or a more appropriate way of doing things?
Thanks.
Looks like you are trying to allow editing of a List of models. I highly suggest you read Phil Haacked - Model Binding To A List. This is a great resource to get started.

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