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C# MVC CMS - Customising Remote Validation

At the link below I asked a question about how to ensure a field does not already contain the same value (for example when there is a unique constraint on a field which correctly causes C# to throw an exception when voilated). With the answer I received, it solved that problem but presented another.
Ensuring another record does not already contain the same value for a field
The main issue I now have is that when I create a new View. The validation works as expected. In brief - The system needs to check that the ViewName and ViewPath (route) are both unique so a search of the DB is required.
However, when I edit the view, the validation kicks in again (and it actually should not because obviously the view exists already because you are editing it).
My issue now is how do I customise the remote validation to work differently for edit vs create. While we should not be able to edit the name of a view to match an existing view, we should also not be stopped from saving the current view simply because it is the same as the current view.
Below is my Model (the part that is not (hopefully) generated by a tool :-):
[MetadataType(typeof(IViewMetaData))]
public partial class View : IViewMetaData { }
public interface IViewMetaData
{
[Required(AllowEmptyStrings = false, ErrorMessageResourceType = typeof(DALResources), ErrorMessageResourceName = "ErrorRequiredField")]
[StringLength(50, ErrorMessageResourceType = typeof(DALResources), ErrorMessageResourceName = "ErrorLessThanCharacters")]
[Display(ResourceType = typeof(DALResources), Name = "ViewName")]
[Remote("IsViewNameAvailable", "Validation")]
string ViewName { get; set; }
[Required(AllowEmptyStrings = false, ErrorMessageResourceType = typeof(DALResources), ErrorMessageResourceName = "ErrorRequiredField")]
[StringLength(400, ErrorMessageResourceType = typeof(DALResources), ErrorMessageResourceName = "ErrorLessThanCharacters")]
[Display(ResourceType = typeof(DALResources), Name = "ViewPath")]
[Remote("IsViewPathAvailable", "Validation")]
string ViewPath { get; set; }
[Display(ResourceType = typeof(DALResources), Name = "ViewContent")]
string ViewContent { get; set; }
}
The part I am having a problem with is the [Remote] validation attribute which is defined below:
[OutputCache(Location = OutputCacheLocation.None, NoStore = true)]
public class ValidationController : Controller
{
private FRCMSV1Entities db = new FRCMSV1Entities();
public JsonResult IsViewNameAvailable(View view)
{
bool isViewNameInvalid = db.View.Any(v => v.ViewName == view.ViewName && v.Id != view.Id);
if (!isViewNameInvalid)
return Json(true, JsonRequestBehavior.AllowGet);
string suggestedViewName = string.Format(UI_Prototype_MVC_Resources.ErrorViewAlreadyExists, view.ViewName);
for (int i = 1; i < 100; i++)
{
string altViewName = view.ViewName + i.ToString();
bool doesAltViewNameExist = db.View.Any(v => v.ViewName == altViewName);
if (!doesAltViewNameExist)
{
suggestedViewName = string.Format(UI_Prototype_MVC_Resources.ErrorViewNotAvailableTry, view.ViewName, altViewName);
break;
}
}
return Json(suggestedViewName, JsonRequestBehavior.AllowGet);
}
public JsonResult IsViewPathAvailable(View view)
{
bool doesViewPathExist = db.View.Any(v => v.ViewPath == view.ViewPath && v.Id != view.Id);
if (!doesViewPathExist)
return Json(true, JsonRequestBehavior.AllowGet);
string suggestedViewPath = string.Format(UI_Prototype_MVC_Resources.ErrorViewAlreadyExists, view.ViewPath);
for (int i = 1; i < 100; i++)
{
string altViewPath = view.ViewPath + i.ToString();
bool doesAltViewPathExist = db.View.Any(v => v.ViewPath == altViewPath);
if (!doesAltViewPathExist)
{
suggestedViewPath = string.Format(UI_Prototype_MVC_Resources.ErrorViewNotAvailableTry, view.ViewPath, altViewPath);
break;
}
}
return Json(suggestedViewPath, JsonRequestBehavior.AllowGet);
}
}
The problem is, the validation needs to work the same on both create and edit. It just needs to do an additional check on edit to ensure we are still referring to the same record and if so, then there is no need to show the validation message because there is nothing wrong.
My question is:
1. How do I get this to work as expected.
2. I can see that both methods are pretty much identical, which violates the DRY principle. How can I make this more generic and simplify it. However the first question is really the one I would like answered because there is no point in refactoring something that doesn't work.
For more information, the above code is also an edit of the code at the following link:
https://msdn.microsoft.com/en-us/library/gg508808(VS.98).aspx
Thanks for any help.

You need to add a parameter to pass the ID property of the model as AdditionalFields. Assuming its int Id, then
[Remote("IsViewPathAvailable", "Validation", AdditionalFields = "Id")]
public string ViewName { get; set; }
and the the method should be
public JsonResult IsViewNameAvailable(string viewName, int? id)
Note that in the Edit view, you include a hidden input for the Id property, so its value will be posted back by the jquery.validate remote function.
You can then check if the id parameter is null (i.e. it's new) or has a value (it's existing) and adjust the queries to suit.
bool isViewNameInvalid;
if (id.HasValue)
{
isViewNameInvalid = db.View.Any(v => v.ViewName == viewName && v.Id != id);
}
else
{
isViewNameInvalid = db.View.Any(v => v.ViewName == ViewName);
}
What is currently happening is that the Remote is only posting the value of the ViewName property, and because your parameter is the model, it is initialized with the default id value (0) and your query is translated to Any(v => v.ViewName == viewName && v.Id != 0);
I also recommend using a view model rather that your partial class
Side note: from the code that generates suggestedViewName, your expecting a lot of ViewName with the same value, meaning your possibly making numerous database calls inside you for loop. You could consider using linq .StartsWith() query to get all the records that start with your ViewName value, and then check the in-memory set in your loop.

View expecting IEnumerable

Well im kinda new in Asp.net Mvc and im learning alone from scratch, i have a aplicattion that controls expends and earnings and what i am trying to do now is, basing on a list of earnings and expends give me the balance from a user, im having a lot of problems trying to control this and i dont know if i am doing it the right way
Here is my model:
public class Balance
{
public int BalanceId { get; set; }
public List<Expense> Despesas { get; set; }
public List<Earning> Rendimentos { get; set; }
public string ApplicationUserId { get; set; }
}
Soo what i did was, first trying to control when the user inserts a Earning or a row like, verifying if the User already exists on the database in the control method Create on the expenses and in the earning, if it doesnt exist he add the aplicationUserId and the expensive or the earning.
I want that the balance appears in every page, soo i added this to my Layout.cshtml
<li>#Html.Action("GetBalance", "Home")</li>
it calls the controller GetBalance:
public PartialViewResult GetBalance()
{
var userId = User.Identity.GetUserId();
var balance = db.Balance.Where(d => d.ApplicationUserId == userId);
return PartialView("_GetBalance",balance);
}
Send to the view _GetBalance the balance model:
#model <MSDiary.Models.Balance>
<p>Saldo: #GetBalance()</p>
#functions
{
HtmlString GetBalance()
{
decimal saldo = 0;
if (Model.Expense.Count != 0 || Model.Earning.Count != 0)
{
foreach (var item in Model.Despesas)
{
balance += item.EarningValue;
}
foreach (var item in Model.Rendimentos)
{
balance -= item.ExpenseValor;
}
}
return new HtmlString(balance.ToString());
}
}
What i want to know is, if there is a easyer way to do this, or what i can do to do what i want, i cant get it why my view expects something different can someone explain me what i am doing wrong?
Ps: Sorry for the long post and English, but i want to learn more :)

Firstly, the model #model <MSDiary.Models.Balance> needs to be changed to:
#model IEnumerable<MSDiary.Models.Balance>
Also, the method GetBalance should ideally be placed in a class not in GetBalance partial view. You could achieve this two ways, either through extension methods or have a Balance View Model that has the calculated balance as a property which is then passed down to your view.
As an example via an extension method:
public static class BalanceExtensions
{
public static string GetBalance(this Balance balance)
{
string displayBalance = "0:00";
// Your logic here
return displayBalance;
}
}
And then in your Partial View you can use the new HTML Helper:
#Html.GetBalance();
As an additional note I would change List to IEnumerable for expenses and earnings as it appears you are only exposing the data and not manipulating the data.
Your model would then look like:
public class Balance
{
public int BalanceId { get; set; }
public IEnumerable<Expense> Despesas { get; set; }
public IEnumerable<Earning> Rendimentos { get; set; }
public string ApplicationUserId { get; set; }
}

#Filipe Costa A few things here.
You should probably name your view the same thing as your method. The underscore preceding the name is fairly standard so I would suggest using that same name for the method. If the name of the method and view are the same you can simply pass in the model and not have to do the name + model signature of PartialView method. It's simpler.
Aside from that your code is fine but your .cshtml partial view should have this for the first line. That will accept the list you're passing.
#model IEnumerable<MSDiary.Models.Balance>
<h1>#Model.BalanceId</h1>
#*Do other stuff!*#

retain values on postback in Asp.net mvc

I have a data in following pattern;
as shown in image attached,
I want to repopulate all these values and controls on Postback.
I am using asp.net MVC
If i should use a list then how can i tackle the multiple values of subject to be saved in one column but on view displayed in different column
currently using forms collection:
int rows=request.Form["rows"];
int colmn=requst.form["comn"];
var list1=new list<mymodel>{
new mymodel {}}
;
for (var row = 1; row <= noOfRows; row++)
{
list1.Add(new mymodel()
{
name= Request.Form["name-row"].ConvertToInt()
rollno= Request.Form["rollno-row"].ToString(),
});
for (int colmn = 1; colmn <= noOfColmns - 1; colmn++)
{
list1.Add(new mymodel()
{
subject = Request.Form["subj-row-colmn"].ConvertToInt()
});
}
}
let me know if something else is needed
Important Note:
I think i am not able to explain what i want,so i have narrowed a problem ,
To be more precise i have created a list ,i have populated a list
as
var list1=new list<mymodel>{
new mymodel {}}
list1.Add(new mymodel()
{
name= Request.Form["name-row"].ConvertToInt(),
rollno= Request.Form["rollno-row"].ToString(),
subj=new list{}
});
,now i want to loop through this list to get all my values back
in the given format.
Q:how to get values from this list using loop(foreach or for) in the desired format?

You will need to bind values to a view model, i.e., List<MyVM> vm on postback. Then, each view model needs to keep a state for the CRUD. It can be a simple key / value pair, like:
public class MyVM
{
#region Properties
#endregion
public Dictionary<string, VMState> States;
}
public class VMState
{
public bool Create { get; set; }
public bool Read { get; set; }
public bool Update { get; set; }
public bool Delete { get; set; }
}

Getting error at time of binding ListBoxFor control in MVC4

When I am changing the "model => model.id" to "model => model.Supplierid" i am getting below error
"The parameter 'expression' must evaluate to an IEnumerable when
multiple selection is allowed."
please have look on below code
// this my model class
public class clslistbox{
public int id { get; set; }
public int Supplierid { get; set; }
public List<SuppDocuments> lstDocImgs { get; set; }
public class SuppDocuments
{
public string Title { get; set; }
public int documentid { get; set; }
}
public List<SuppDocuments> listDocImages()
{
List<SuppDocuments> _lst = new List<SuppDocuments>();
SuppDocuments _supp = new SuppDocuments();
_supp.Title = "title";
_supp.documentid = 1;
_lst.Add(_supp);
return _lst;
}
}
// this my controller
[HttpGet]
public ActionResult AddEditSupplier(int id)
{
clslistbox _lst = new clslistbox();
_lst.lstDocImgs= _lst.listDocImages();
return View(_lst);
}
// this is view where i am binding listboxfor
#model clslistbox
#using (Html.BeginForm("AddEditSupplier", "Admin", FormMethod.Post))
{
#Html.ListBoxFor(model => model.id, new SelectList(Model.lstDocImgs, "documentid", "title"))
}
Can anyone see the reason for it?

I think the changing of the property in the expression here is a red-herring - it won't work in either case.
Update
However, see at the end of my answer for some probably needlessly detailed exposition on why you didn't get an error first-time round.
End Update
You're using ListBoxFor - which is used to provide users with multiple selection capabilities - but you're trying to bind that to an int property - which cannot support multiple selection. (It needs to be an IEnumerable<T> at least to be able to bind a list box to it by default in MVC)
I think you mean to be using DropDownListFor - i.e. to display a list of items from which only one can be selected?
If you're actually looking for single-selection semantics in a listbox, that's trickier to do in MVC because it's Html helpers are geared entirely around listboxes being for multiple selection. Someone else on SO has asked a question about how to get a dropdown to look like a list box: How do I create a ListBox in ASP.NET MVC with single selection mode?.
Or you could generate the HTML for such a listbox yourself.
(Update) - Potentially needlessly detailed exposition(!)
The reason you don't get an exception first time round is probably because there was no value for id in ModelState when the HTML was generated. Here's the reflected MVC source (from SelectExtensions.SelectInternal) that's of interest (the GetSelectListWithDefaultValue call at the end is the source of your exception):
object obj =
allowMultiple ? htmlHelper.GetModelStateValue(fullHtmlFieldName, typeof(string[])) :
htmlHelper.GetModelStateValue(fullHtmlFieldName, typeof(string));
if (!flag && obj == null && !string.IsNullOrEmpty(name))
{
obj = htmlHelper.ViewData.Eval(name);
}
if (obj != null)
{
selectList =
SelectExtensions.GetSelectListWithDefaultValue(selectList, obj, allowMultiple);
}
Note first that the control variable allowMultiple is true in your case, because you've called ListBoxFor. selectList is the SelectList you create and pass as the second parameter. One of the things that MVC (unfortunately in some cases) does is to use ModelState to modify the select list you pass when re-displaying a view in order to ensure that values which were set in ModelState via a POST are re-selected when the view is reloaded (this is useful when page validation fails because you won't copy the values to your underlying model from ModelState, but the page should still show those values as being selected).
So as you can see on the first line, the model's current value for the expression/field you pass is fished out of model state; either as a string array or as a string. If that fails (returns null)then it makes another go to execute the expression (or similar) to grab the model value. If it gets a non-null value from there, it calls SelectExtensions.GetSelectListWithDefaultValue.
As I say - what you're trying to do will ultimately not work in either the case of Id or SupplierId (because they would need to be IEnumerable) but I believe this ModelState->Eval process is yielding a null value when you use Id, so the process of getting an 'adjusted' SelectList is skipped - so the exception doesn't get raised. The same is not true when you use SupplierId because I'll wager that there's either a value in ModelState at that point, or the ViewData.Eval successfully gets an integer value.
Not throwing an exception is not the same as working!.
End update

Try changing your property from int to int[]
public class SuppDocuments
{
public string Title { get; set; }
public int documentid { get; set; }
}
Assuming above is the class used for binding the model , try changing the documentid property as below
public class SuppDocuments
{
public string Title { get; set; }
public int[] documentid { get; set; }
}

IEnumerable to IList casting possibilites

I am trying to ensure that my fields and page options are valid and on one page i want to check and see if an item is selected or not - which a selection is required to save.
I have the following:
in ViewEntry: public IList<Guid> Parties { get; set; }
in my ViewModel: public IEnumerable<Guid> PartiesSelected { get; set; }
Here is my ensure valid code:
public void EnsureValid(VisitEntry visitEntry)
{
var errors = new RulesException<VisitActivityEntryDTO>();
if(visitEntry.Parties == null )
errors.ErrorForModel(string.Format("No {0} selected", Kids.Resources.Entities.Party.EntityNamePlural));
if (errors.Errors.Any())
throw errors;
}
and in my controller my Get Edit method when loading the page I have:
viewModel.PartiesSelected = visitEntry.VisitEntryParties.Select(v=>v.PartyId);
Is it possible in any way that i could possibly have:
viewEntry.Parties = viewModel.PartiesSelected
or
viewEntry.Parties = visitEntry.VisitEntryParties.Select(v=>v.PartyId);
I mainly want to have the selected party to show up in the list of Parties for the ViewEntry so when i validate.

viewEntry.Parties = viewModel.PartiesSelected.ToList()