Develop Reference

Causing problems with foreach into my mvc

This is how I have made a previous post as you can see here.
must retrieve the list from the database
I have tried to make my foreach which have been previously described. but it causes problems for not running my foreach in through while making the mistake on it.
Index.cshtml
#foreach (var u in Model)
{
<div class="col-md-6 col-sm-6">
<div class="plan">
<h3>#u.Name<span>$#u.Price</span></h3>
<p>#u.Text</p>
</div>
</div>
}
and undervisningController.cs
// GET: Undervisning
public ActionResult Index()
{
DatabaseClasseDataContext db = new DatabaseClasseDataContext();
var model = db.Packages.ToList();
return View(model);
}
And the top on index.cshtml have i:
#model MentorOrdblind_MVC.Models.Undervisning.Undervisning
Model Undervisning.cs
public class Undervisning
{
public string Name { get; set; }
public decimal Price { get; set; }
public int Hours { get; set; }
public string Text { get; set; }
}

You are passing your view a List<T> but your model is not a type of IEnumerable. So your view is only expecting a single object of the type Undervisning and not a collection.
Use this:
#model IEnumerable<MentorOrdblind_MVC.Models.Undervisning.Undervisning>

Change your model delcaration to:
#model IEnumerable<MentorOrdblind_MVC.Models.Undervisning.Undervisning>
At this moment your model is a single class, not a list of objects

Always keep in mind what is being passed from controller action to view. If you pass only model from the action then use the model reference in the respective view of the action. If you pass List then use IEnumerable model reference in the view.
If you pass list from action then in the view use:
#model IEnumerable<your model> in the top as reference
If you pass model without a list then use:
#model your model
In your case you are passing list so use IEnumerable of your desired model class.
Thanks

Bind checkboxes to List in partial view

I have a CreateViewModel.
public class CreateViewModel
{
public AttributesViewModel AttributesInfo { get; set; }
}
The AttributesViewModel is sent to a partial view.
public class AttributesViewModel
{
public AttributesViewModel()
{
ChosenAttributes = new List<int>();
}
public List<Attributes> Attributes { get; set; }
public List<int> ChosenAttributes { get; set; }
}
The List of Attributes is outputted in the partial view. Each one has a checkbox.
foreach (var attribute in Model.Attributes)
{
<input type="checkbox" name="ChosenAttributes" value="#attribute.ID" /> #Attribute.Name
}
When I post CreateViewModel, AttributesInfo.ChosenAttributes is always empty even though I checked some boxes. How do I properly name each checkbox so that it binds to the ChosenAttributes List?
My Solution
I took Stephen Muecke's suggestion to do the two way binding. So, I created a CheckboxInfo class that contained Value, Text, and IsChecked. I created a EditorTemplate for it:
#model Project.CheckboxInfo
#Html.HiddenFor(model => model.Text)
#Html.HiddenFor(model => model.Value)
#Html.CheckBoxFor(model => model.IsChecked) #Model.Text
One GIANT caveat. To get this to work properly, I had to create an EditorTemplate for the AttributesViewModel class. Without it, when CreateViewModel is posted, it cannot link the checkboxes to AttributesInfo.

Your naming the checkbox name="ChosenAttributes" but CreateViewModel does not contain a property named ChosenAttributes (only one named AttributesInfo). You may be able make this work using
<input type="checkbox" name="AttributesInfo.ChosenAttributes" value="#attribute.ID" /> #Attribute.Name
but the correct approach is to use a proper view model that would contain a boolean property (say) bool IsSelected and use strongly typed helpers to bind to your properties in a for loop or using a custom EditorTemplate so that your controls are correctly names and you get 2-way model binding.

I had a similar scenario, but this was how I did it. The solution is not perfect so please excuse if I have left something out, but you should be able to relate. I tried to simplify your solution as well :)
I changed the Attribute class name to CustomerAttribute, rename it to whatever you like, use a singular name, not plural. Add a property to your CustomerAttribute class, call it whatever you like, I called mine IsChange.
public class CustomerAttribute
{
public bool IsChange { get; set; }
// The rest stays the same as what you have it in your Attributes class
public string Name { get; set; } // I'm assuming you have a name property
}
Delete your AttributesViewModel class, you don't really need it, I like simplicity.
Modify your CreateViewModel class to look like this:
public class CreateViewModel
{
public CreateViewModel()
{
CustomerAttributes = new List<CustomerAttribute>();
}
public List<CustomerAttribute> CustomerAttributes { get; set; }
}
Your controller will look something like this:
public ActionResult Create()
{
CreateViewModel model = new CreateViewModel();
// Populate your customer attributes
return View(model);
}
Your post controller action method would look something like this:
[HttpPost]
public ActionResult Create(CreateViewModel model)
{
// Do whatever you need to do
}
In your view, you will have something like this:
<table>
<tbody>
#for (int i = 0; i < Model.CustomerAttributes.Count(); i++)
{
<tr>
<td>#Html.DisplayFor(x => x.CustomerAttributes[i].Name)</td>
<td>#Html.CheckBoxFor(x => x.CustomerAttributes[i].IsChange)</td>
</tr>
}
<tbody>
</table>
Create a sample app and try out the code above and see if it works for you.

Handling nested collections with mvc4 view to controller

I've been struggling for a few hours on a concept that I feel should be simple. I have a Model that is essentially a Quiz with a Collection of Questions and that collection has a collection of Answers. Here is a example of my model (simplified):
public class QuizModel
{
public List<Question> Questions { get; set; }
}
public class Question
{
public string TheQuestion { get; set; }
public List<Answer> Answers { get; set; }
}
public class Answer
{
public string Value { get; set; }
}
And the troublesome part, my view:
#using (Html.BeginForm("SubmitQuiz", "Quiz", FormMethod.Post, new { role = "form" }))
{
<ol>
#{
#Html.Hidden("Id", Model.Id, new { Id="pQuizModel"})
for (int vQIndex = 0; vQIndex < Model.Questions.Count; vQIndex++)
{
<li>
#Model.Questions.ElementAt(vQIndex).Question
<ul class="list-unstyled">
#{
for (int vAIndex = 0; vAIndex < Model.Questions.ElementAt(vQIndex).Answers.Count; vAIndex++)
{
<li>#Html.RadioButtonFor(pModel => pModel.Questions.ElementAt(vQIndex).SelectedAnswer, Model.Questions.ElementAt(vQIndex).Answers.ElementAt(vAIndex).Value) #Model.Questions.ElementAt(vQIndex).Answers.ElementAt(vAIndex).Value</li>
//<li>#Html.RadioButton(Model.Questions.ElementAt(vQIndex).Id.ToString() + ":" + Model.Questions.ElementAt(vQIndex).Answers.ElementAt(vAIndex).Id, Model.Questions.ElementAt(vQIndex).Answers.ElementAt(vAIndex).Id)
// #Model.Questions.ElementAt(vQIndex).Answers.ElementAt(vAIndex).Value</li>
}
}
</ul>
</li>
}
}
</ol>
<button type="submit" class="btn btn-default">Submit</button>
}
My controller, just trying to debug it and make sure the Model is filled out properly:
public ActionResult SubmitQuiz(QuizModel pQuizModel)
{
return View();
}
I've literally tried a ton of different suggestions on my view. It's pretty easy to bind directly to a single value in a Model, I can even get my pQuizModel to have the correct Hidden piece you see in the View. But nothing else in the Model gets populated and I can't figure out why.\
Edit: To clarify my problem, the view is good but the controller does not receive any values in the pQuizModel parameter. I don't have the binding setup properly, need some help there.

The problem is not with the Razor rendering of your initial page, it's with the model binder on the resulting POST (after they push the button). The model binder makes certain assumptions about how to map ids into nested items. Because you're not following the convention as you form your Razor code, it isn't filling the method's input properties. See http://www.hanselman.com/blog/ASPNETWireFormatForModelBindingToArraysListsCollectionsDictionaries.aspx for a similar example.

Create (not read) field values into a new view in C# MVC

I've looked, tried several different solutions and haven't found anything that works (at least, not something with an example close enough to what I want for me to follow). I'm sure I'm missing something that would be a simple thing to a more experienced coder. Help?
I have a Model called Residents. It includes ResidentID, PFName, PLName. I have a controller for Residents. I have CRUD views for Residents. All working just fine.
I have a Model called Logs. It includes LogID, ResidentID, Comments. I have a controller for Logs. I have CRUD views for Logs. All working just fine.
I can display all the log entries for a Resident. Works fine. After a Log entry has been created, I can display the PFName using the method
#Html.DisplayFor(model => model.Resident.PFName)
Next, I want to Create a new log entry for a selected Resident.
That's where I'm having the problem. I would like the "Create" view (for the Log) to display the ResidentFName and ResidentLName of the selected resident, not the ResidentID.
A this point, from the Details view for a Resident, I have a CreateLog link.
#Html.ActionLink("New Log Entry", "../Log/Create", new { #ResidentID = Model.ResidentID})
This (likely not the best way) gives me a URL with the value of the selected ID
http://localhost:999/Log/Create?ResidentID=1
The value for the ResidentID is correct; it changes depending on which Resident is selected.
This value is correctly entered
#Html.TextBoxFor(model => model.ResidentID)
on the new CreateLog page using the Log Controller Create action.
public ActionResult Create(int ResidentID)
I plan to hide the ResidentID TextBox so the user doesn't see it. It seems I have to make it available in the form to be able create a new log entry.
The CreateLog form currently works as I have it now. I can create a log entry and verify that entry has been correctly recorded for the Resident.
But, I would like the form to display the PFName and PLName for the Resident so the user has visible feedback for which Resident was selected.
I believe that the related data (PFName and PLName) I want has to be passed to the CreateLog form .... somehow. I can't get it from the form.
Since there's only the unsaved entry for ResidentID, I can't use the value from the CreateLog form it to display related data. As mentioned, for the Lists, there is no such problem. It's only for CreateLog.
I've tried adding the data to the URL. Not working. I've tried setting the strings in the Controller (and the URL). Not working. I've looked at setting a cookie, but haven't ever done that so not sure what to set or where to put it or how to get the values from it. I've looked at setting a variable in the controller ... (have that working to display drop down lists, but a list to select from is not what I need -- I want the matching values from the related table).
Log.LogID(PK, Identity)
Log.ResidentID(FK)
Resident.PFName
Resident.PLName
I can directly create a view with these tables/fields in my SQLDB and update it.

Assuming a view model which looks something like this:
public class CreateLogViewModel
{
public int ResidentID { get; set; }
public string PFName { get; set; }
public string PLName { get; set; }
public string SomeLogCreationProperty { get; set; }
// other properties
}
Your controller could look something like this:
public ActionResult Create(int ResidentID)
{
var model = db.Residents.Where(r => r.ResidentID == ResidentID)
.Select(r => new CreateLogViewModel
{
ResidentID = r.ResidentID,
PFName = r.PFName,
PLName = r.PLName
// other properties
});
return View(model);
}
Then the view:
#model CreateLogViewModel
#using (Html.BeginForm())
{
#Html.HiddenFor(m => m.ResidentID)
#Html.HiddenFor(m => m.PFName)
#Html.HiddenFor(m => m.PLName)
#Html.EditorFor(m => m.SomeLogCreationProperty)
// other properties
<input type="submit" />
}
This would then POST back to:
[HttpPost]
public ActionResult Create(CreateLogViewModel model)
{
if (ModelState.IsValid)
{
return RedirectToAction("Index");
}
// Redisplay the form with errors
return View(model);
}

Expanding on John H and StuartLC answers, you need to use ViewModels and the following workflow:
Database->(load)->Model->Controller->(convert)->ViewModel->View
and
View->ViewModel->Controller->(convert)->Model->(save)->Database
So lets says you have the following models:
namespace Models
{
public class Residents
{
public int ResidentID { get; set; }
public string PFName { get; set; }
public string PLName { get; set; }
//...
}
public class Logs
{
public int LogID { get; set; }
public int ResidentID { get; set; }
public string Comments { get; set; }
//...
}
}
You need a ViewModel that combines the data you need for display and input in your Log\CreateView:
namespace ViewModels
{
public class ResidentLog
{
public int ResidentID { get; set; }
public string PFName { get; set; }
public string PLName { get; set; }
public string Comments { get; set; }
//...
}
}
Then inside the controller:
public class LogController : Controller
{
[HttpGet]
public ActionResult Create(int ResidentID)
{
// Run in debug and make sure the residentID is the right one
// and the resident exists in the database
var resident = database.Residents.Find(residentID);
var model = new ViewModels.ResidentLog
{
ResidentID = resident.ResidentID,
PFName = resident.PFName,
PLName = resident.PLName,
Comments = string.Empty,
// ...
};
// Run in debug and make sure model is not null and of type ResidentLog
// and has the PFName and PLName
return View(model);
}
[HttpPost]
public ActionResult Create(ViewModels.ResidentLog model)
{
if (!ModelState.IsValid)
return View(model);
var log = new Models.Logs
{
// Assumes LogID gets assigned by database?
ResidentID = model.ResidentID,
Comments = model.Comments,
};
// Run in debug and make sure log has all required fields to save
database.Logs.Add(log);
database.SaveChanges();
return RedirectToAction("Index"); // Or anywhere you want to redirect
}
}
Then your Log\CreateView:
#model ViewModels.ResidentLog
<!-- Display the values needed -->
<div>#Model.ResidentID - #Model.PFName - #Model.PLName</div>
#using (var form = Html.BeginForm(...))
{
<!-- This saves the values for the post, but in fact only ResidentID is actually used in the controller -->
#Html.HiddenFor(m => m.ResidentID)
#Html.HiddenFor(m => m.PFName)
#Html.HiddenFor(m => m.PLName)
#Html.EditorFor(m => m.Comments)
<input type="submit" />
}

You need to provide the additional information to the view.
This can be done in at least 2 ways
Use the ViewBag dynamic as a quick and dirty cheap and cheerful container to pass everything the view needs from the controller.
(preferred) Use a custom ViewModel with a tailor made class which holds everything the view needs. This is generally preferred as it is statically typed.
(I'm assuming that resident is already persisted in the database by the time the Log controller is called - you might need to fetch it elsewhere)
So, in your log controller, here's an example of using ViewBag:
[HttpGet]
public ActionResult Create(int residentID)
{
ViewBag.Resident = Db.Residents.Find(residentId);
return View();
}
You can then show the resident properties on the view by utilizing the ViewBag.
Edit
Yes, by persisted I meant in the Db - apologies about using unclear jargon.
Here's another example of ViewBag approach (the idea is to create a new Comment for another object):
Doing this the cheap + cheesy ViewModel way - in the HTTPGet Controller Create method:
public ActionResult Create(string objectType, int objectId)
{
// This is equivalent to youn fetching your resident and storing in ViewBag
ViewModel.Object = FetchSomeObject(objectType, objectId);
return View();
}
And in the View I use this (The ViewBag is accessible to Controller and View):
<title>#string.Format("Add new Comment for {0} {1}", ViewBag.Object.ObjectType, ViewBag.Object.Name);</title>
As you say, you will also need to do add a hidden for the ResidentId in your create log form
As per #JohnH's answer (+1), the BETTER way to do this (than using the magic ViewBag dynamic) is to create a custom ViewModel specifically for this screen. The ViewModel can either be reused both ways (GET: Controller => View and POST : Browser => Controller, or you even have separate ViewModels for the Get and Post legs.

With much thanks to all, I have it working. The final piece was telling the controller to return the model (nl). Here's the full spec for what's working:
I have created a ViewModel that includes
public class NewLog
{
public int ResidentID { get; set; }
public string PFName { get; set; }
public string PLName { get; set; }
public string Comment { get; set; }
// other properties
}
In the LogController,
public ActionResult Create(int ResidentID)
{
var resident = db.Residents.Find(ResidentID);
var nl = new NewLog
{
ResidentID = ResidentID,
PFName = resident.PFName,
PLName = resident.PLName,
Comment = string.Empty,
};
return View(nl);
}
In the Create.cshtml page,
#model My.Models.NewLog
The required ResidentID to be recorded with the new Log Entry
#Html.TextBoxFor(model => model.ResidentID, new {#Type = "Hidden"})
And the related, user-friendly display boxes for the person's name
#Html.DisplayFor(model => model.PFName)
#Html.DisplayFor(model => model.PLName)
And in the URL which is used to access the create page,
#Html.ActionLink("New Log Entry", "../Log/Create", new { #ResidentID = item.ResidentID, item.PFName, item.PLName})

How to persist ICollection entity property between requests in Razor

I am working on ASP.NET MVC 4 application. I use EF 5 and Code First. I have two entities with 1:N relation:
public class Menu
{
//some properties
public virtual ICollection<Document> Documents { get; set; }
}
and:
public class Document
{
//some properties..
public int MenuID { get; set; }
public virtual Menu Menu { get; set; }
}
I have Edit view with [HttpPost] and [HttpGet] methods. When I pass the model through the GET action like this :
Menu model = unitOfWork.MenuRepository.GetById(Id);
if (model != null)
{
return View(model);
}
everything is right, I can see that model contains 1 Documents but then in my razor view if I simply try:
#Html.HiddenFor(m => m.Documents)
then when I submit the form to the Post action I can see that the Documents property is null.
How can keep Documents persistent?

Anything with a collection will not get rendered as you are expecting. you need to create say, a displaytemplate which expects a collection and then render our the properties of the documents in a HiddenFor or if you dont want a display template then do the same but on the view in question.
for example, this is what you need to do:
#for(int counter = 0; counter < Model.Documents; counter++)
{
#Html.HiddenFor(m => Model.Documents[counter].Id)
#Html.HiddenFor(m => Model.Documents[counter].Title)
// and so on
}
so now when you postback, it has all the properties it needs for the engine to bind to and pass it to your controller method and serve it up.

Have you looked through the html, that is generated ? Take a look )
This answer and this one provide workarounds.