I use viewModels to communicate between my controller and my view.
To get model validation, i use a partial class like this :
[MetadataType(typeof(EvaluationValidation))]
public partial class Evaluation
{
public class EvaluationValidation
{
[DisplayName("Title of evaluation")]
[Required( ErrorMessage="Please give a title")]
public string Title { get; set; }
}
}
The Displayname is binded to view with no problem but when i try to submit the view, i get this error :
The model item passed into the
dictionary is of type
'FOOBAR.Models.Evaluation',
but this dictionary requires a model
item of type
'FOOBAR.Areas.Evaluation.ViewModels.EvaluationFormViewModel'.
This is the code used in my controller
[HttpPost]
public ActionResult Create(FormCollection formValues)
{
Models.Evaluation data = new Models.Evaluation();
if (TryUpdateModel(data, "evaluations"))
{
this.daoe.Create(data);
return RedirectToAction("Index");
}
return View(data);
}
And this is my viewModel
public class EvaluationFormViewModel
{
public FOOBAR.Models.Evaluation evaluations;
public SelectList selectlist_evaluationtypes { get; set; }
public SelectList selectlist_evaluationstatus { get; set; }
}
Have you got an idea ?
Thank's by advance
You are passing a Models.Evaluation instance to your view, which is bound to a model of another type.
Models.Evaluation data = new Models.Evaluation();
if (TryUpdateModel(data, "evaluations"))
{
// ...
}
return View(data);
If TryUpdateModel returns false (which happens when the form does not pass validation, for example), you are effectively passing data to the View, which is of type Models.Evaluation.
Try mapping it to type FOOBAR.Areas.Evaluation.ViewModels.EvaluationFormViewModel before passing it to the view.
Related
I am quite new to C# and asp.net mvc and I have been trying to find an answer to my question here and in other foras but have not succeeded. However if this question has been asked and answered before then I apologize and could you please link to that post.
I am trying to create a treeview where I pass a list of ViewModels to my View.
I use code-first approach and have added a migration between my model and the database.
My problem is how to pass a list of objects of the ViewModel to the View?
I can pass a list of objects of the model from the controller but how to pass a list of objects of the ViewModel? Is that possible?
Maybe there is a simple solution to this that I have not found yet and maybe I am doing this all wrong. Anyway I really need some help.
public class MyClass
{
public int Id { get; set; }
public int ParentId { get; set; }
public string Name { get; set; }
}
public class MyClassViewModel
{
public MyClass Parent { get; set; }
public List<MyClass> Children
{
get { return GetChildren(); }
}
public List<MyClass> GetChildren()
{
var listOfChildren = new List<MyClass>().Where(c => c.ParentId ==
Parent.Id).ToList();
return listOfChildren;
}
}
public ActionResult CreateTree()
{
var viewModel = new MyClassViewModel();
//This only returns one instance of an object, how to return a list?
return View("CreateTree", viewModel);
}
It is very simple, you just pass the list of your view model to the view:
[HttpGet()]
public IActionResult CreateTree()
{
List<MyViewModel> viewModelList = MyViewModel.GetList();
return View("CreateTree", viewModelList);
}
On the view, you set the expected type for the model via the #model directive.
#model List<MyViewModel>
#{
//stuff
}
Now you can just iterate through your list of viewmodel.
#foreach (MyViewModel item in Model)
{
//stuff
}
You could create a class, containing a list of your ViewModels
public class ModelWithListOfViewModels
{
public List<ViewModel> ViewModels { get; set; }
}
Add your ViewModels to the list in the controller
public ModelWithListOfViewModels model { get; set; }
[HttpGet()]
public ActionResult FillList()
{
model = new ModelWithListOfViewModels();
//Here you fill the list with the ViewModels you want to pass to the View
model.ViewModels.Add(/** ViewModel here **/);
return View("CreateTree", model);
}
Then simply loop over the list to get your model in the View
#model ModelWithListOfViewModels
#foreach (var vm in Model.ViewModels)
{
//use vm to get access to a ViewModel added in the list
}
I'm having trouble passing a viewmodel into a view. I have two views: a Search view and a GeneralForm view. Search passes search results into GeneralForm's viewmodel.
Say the GeneralForm is a complex viewmodel that holds two other viewmodels:
public class GeneralFormViewModel
{
public GeneralInfoViewModel GeneralInfo { get; set; }
public NotesViewModel Notes { get; set; }
}
public class GeneralInfoViewModel
{
[Required(ErrorMessage = "Please enter the person's name.")]
[DisplayName("Name:")]
public string Name { get; set; }
[Required(ErrorMessage = "Please enter the person's ID.")]
[DisplayName("ID:")]
public int ID { get; set; }
}
public class NotesViewModel
{ // etc.
(I set up this way in order to use multiple #Html.BeginForms on my GeneralForm view. In this way, I hope to POST and validate small sections of the entire general form, one at a time, using KnockoutJS and AJAX.)
[HttpPost]
public ActionResult Search(SearchViewModel vm)
{
var query = // do some searching
var viewmodel = new GeneralFormViewModel()
{
GeneralInfo = new GeneralInformationViewModel
{
ID = query.id,
Name = query.name
}
};
return RedirectToAction("GeneralForm", viewmodel);
}
At this point, viewmodel.GeneralInfo is not null, and the viewmodel is passed to the GeneralForm controller.
[HttpGet]
public ActionResult GeneralForm(GeneralFormViewModel model)
{
return View(model);
}
Now model.GeneralInfo is null. What conventions of MVC am I breaking by doing this, and how can I get the GeneralForm view to render the data acquired via the Search controller to the GeneralForm view?
Problem is You can't send data with a RedirectAction.
you're doing a 301 redirection and that goes back to the client.
Store it in a TempData or Session ...
See the following post:
passing model and parameter with RedirectToAction
I have model:
public class MyModel
...fields
[Remote(ActionName, ControllerName)]
public string SomeNumber { get; set; }
..fields
And have a action in ControllerName controller:
public JsonResult ActionName(string someNumber)
{...}
But when actions is invoked the parameter someNumber is allways null.
And when I try to debug it I get
GET /ControllerName/ActionName?MyModel.SomeNumber =34189736
How can I make it work?
(I can't pass whole model MyModel, and cant change MyModel.SomeNumber name of field in my view)
UPD. Input in my view:
<input data-val="true" data-val-remote-additionalfields="*.SomeNumber" data-val-remote-url="/ControllerName/ActionName" id="MyModel_SomeNumber" name="MyModel.SomeNumber" type="text" value="34189734" class="valid">
UPD solved! :)
I create new model with single field SomeNumber and use prefix:
SomeNumber([Bind(Prefix = "MyModel")]MySingleFieldModel model)
If you're using nested ViewModels, you'll need to accept the parent ViewModel as the argument in your Validation action. For example:
public class ParentViewModel
{
public UserViewModel User {get; set; }
//....
}
public class UserViewModel
{
[Remote("UniqueUsername", "Validation")]
public string Username { get; set; }
//....
}
In ValidationController:
public class ValidationController : Controller
{
public JsonResult UniqueUsername(ParentViewModel Registration)
{
var Username = Registration.User.Username; //access the child view model property like so
//Validate and return JsonResult
}
}
Try using you model as the parameter.
So that it could bind the value to it.
public JsonResult ActionName(MyModel model)
{
//...
model.SomeNumber;
//...
return Json(validationResult, JsonRequestBehavior.AllowGet)
}
public JsonResult ActionName(string SomeNumber)
{...}
I think you may need to match case on your input parameter.
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Generic partial view: how to set a generic class as model?
I am trying to build common functionality using generic types but got stuck with below scenario.
View Model
public class DeleteForm<T>
{
public LogInfo Ticket { get; set; }
public string Id { get; set; }
public DeleteForm() {
Ticket = new LogInfo();
}
public DeleteForm(T viewModel) : this() {
ViewModel = viewModel;
}
public T ViewModel { get; set; }
}
Controller
public ActionResult Index(string name)
{
return View("index", new DeleteForm<List<Users>>(new List<Users>());
}
List Screen
#model DeleteForm<List<Users>>
//gridview displays list of users
#Html.Partial("revisionwindow", Model)
Partial View
#model DeleteForm<T> <---Its not working
#Html.EditorFor(o=>o.Ticket)
#Html.EditorFor(o=>o.Id)
use dynamic model instead.
your partial view can look something like this :
#model dynamic
#{
var myModel = (DeleteForm<List<Users>>) Model;
}
#Html.EditorFor(o=>myModel.Ticket)
#Html.EditorFor(o=>myModel.Id)
hope this help.
If you pass a model to view, it has to be strongly-typed (particular type).
So SomeClass<T> type won't work. Instead of generic type a base class could fill
your requirements. What I mean is:
View Model
public abstract class Form
{
public Form()
{
Ticket = new LogInfo();
}
public LogInfo Ticket {get; set;}
public int Id {get; set;}
}
public class DeleteUsersForm: Form
{
public DeleteUsersForm(IEnumerable<Users> users):base()
{
this.ViewModel = users;
}
public IEnumerable<Users> ViewModel {get; set;}
}
Controller
public ActionResult Index(string name)
{
return View(new DeleteUsersForm(new List<Users>()));
}
List Screen
#model DeleteUsersForm
//displays list
#Html.Partial("revisionwindow", Model)
Partial View
#model Form
#Html.EditorFor(o=>o.Ticket)
#Html.EditorFor(o=>o.Id)
Untill now in C# MVC3 i only had to use one controller which used only one model.
But now i think i need access to two models in my controller. I'm wondering if this is allowed in the MVC pattern?
I have a ProfileController. The ProfileController shows the profile info of a user obviously. But there's also some other data that i wish to show, like the groups a user created. For that i also have a GroupsModel.
How am i supposed to get both data from one controller?
How am i supposed to get both data from one controller?
By using a view model:
public class MyViewModel
{
public ProfileModel Profile { get; set; }
public GroupsModel Groups { get; set; }
}
and then passing this view model to the view:
public ActionResult ShowProfile()
{
var model = new MyViewModel();
model.Profile = ...
model.Groups = ...
return View(model);
}
And now your view will be strongly typed to the view model:
#model MyViewModel
and you can display information:
#Html.DisplayFor(x => x.Profile.SomeProperty)
Assuming that you aren't putting too much into a single view/controller, why not compose a simple view model which has the data you need?
public class ProfileInfo
{
public Person Person
{
get;
set;
}
public List<Group> Groups
{
get;
set;
}
}