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.
Related
I have a model like
public class Model
{
public int Value { get; set; }
public List<OtherModel> List { get; set; }
}
public class OtherModel
{
public int Value1 { get; set; }
public int Value2 { get; set; }
public bool IsPropTrue { get; set; }
}
I am using Model in a View where I'm looping through the List to show data in a table.
Depending on whether one of the properties (IsPropTrue) in OtherModel is true or false, I want to use the HiddenFor Html helper and send the data to the HttpPost controller.
#model Model
#foreach (var item in Model.List)
{
if (item.IsPropTrue)
{
#Html.HiddenFor(model=> item.Value1)
#Html.HiddenFor(model=> item.Value2)
}
}
I think it doesn't work because I should in some way add these properties to the OtherModel, which is inside the Model; But the way I have it now, I am adding properties to Model.
you can do it like this :
#model Model
#foreach (var item in Model.List)
{
if (item.IsPropTrue)
{
#Html.HiddenFor(model => model.List[Model.List.IndexOf(item)].Value1)
#Html.HiddenFor(model => model.List[Model.List.IndexOf(item)].Value2)
}
}
this way the binding system will bind the hidden fields with your List OtherModel in the Model
if you want send an array to server based on the Model you have to use indexer in #Html.HiddenFor .
#model WebApplication1.Models.MyModel
<form>
#if (Model != null && Model.List != null)
{
for (int i = 0; i < Model.List.Count; i++)
{
if (Model.List[i].IsPropTrue)
{
#Html.HiddenFor(model => Model.List[i].Value1)
#Html.HiddenFor(model => Model.List[i].Value2)
}
}
}
<button type="submit">submit</button>
</form>
if you want know reason of using indexer on model i recommend How does MVC 4 List Model Binding work?
Consider if it the responsibility of the view or the controller action to make the decisions - you can send everything back to the action to do the decision making.
In your Views/Shared folder, create a controller called EditorTemplates
In this folder, add a partial view called OtherModel
In this view, set the model to OtherModel and set the Layout=null
Add the three OtherModel fields in EditorFor (and HiddenFor if not displaying isPropTrue). This partial view displays just one instance of your list.
In your main view, use the above editor model like so. MVC will take care of all rendering and postback of the Model State for your complete list of items. We like one-liners...
#Html.EditorFor(model => model.OtherModel)
When the data is subsequently posted back to an action, Model State has wrapped up all of your displayed items into a list again, so you can check the isPropTrue value for each item on the server.
The only issue with MVC is that is you pass an empty list out to a view, you get a null value back, so just replace this with an empty list when null is returned
My target is, to modify a model in more than one view.
Since sometimes my models have many properties I want to modify them in more than one view. Something like:
first page edits 2 properties, second page edits 3 other properties,...
the model looks like this:
public class LoadViewModel
{
public int CurrentPage { get; set; } = -1;
public PageViewModel PageViewModel { get; set; }
}
public class PageViewModel
{
public string Param1 { get; set; }
public string Param2 { get; set; }
public int Param3 { get; set; }
}
my view on the Index-page looks like this:
#model LoadViewModel
#using(Ajax.BeginForm("Load", "Home", new AjaxOptions {UpdateTargetId = "page"}, new {lvm = Model}))
{
<div id="page"></div>
<input type="submit"/>
}
and this is my action:
public ActionResult Load(LoadViewModel lvm = null)
{
if (lvm == null) lvm = new LoadViewModel();
lvm.CurrentPage += 1;
TempData["CurrentPage"] = TempData["CurrentPage"] == null ? 0 : (int)TempData["CurrentPage"] + 1;
if (!partialViewDict.ContainsKey((int) TempData["CurrentPage"]))
TempData["CurrentPage"] = 0;
return PartialView(partialViewDict[(int)TempData["CurrentPage"]], lvm);
}
the pages are just partials that are mapped:
private Dictionary<int, string> partialViewDict = new Dictionary<int, string>
{
{0, "Pages/_Page1"},
{1, "Pages/_Page2"},
{2, "Pages/_Page3"},
};
and designed like this:
#using WebApplication1.Controllers
#model LoadViewModel
#{
TempData["CurrentPage"] = 0;
}
#Html.DisplayNameFor(m => m.PageViewModel.Param1)
#Html.EditorFor(m => m.PageViewModel.Param1)
this is working. When switching to Page2 the model is correctly set, but when hitting the submit the value of Param1 (that I set in Page1) is resetted to null and only the values I set in the current partial are correct.
This is Page2:
#using WebApplication1.Controllers
#model LoadViewModel
#{
TempData["CurrentPage"] = 1;
}
#Html.DisplayNameFor(m => m.PageViewModel.Param2)
#Html.EditorFor(m => m.PageViewModel.Param2)
When I add a #Html.HiddenFor(m => m.PageViewModel.Param1) into the partial, the value is still set. But I don't want the values to be resetted. I don't want to add an #Html.HiddenFor for all properties a set in a previous view. How can I prevent that the values are resetted when hitting submit without adding #Html.HiddenFor for all not listed attributes? Or is there any other possibility to catch my target?
There's two pieces to this. First, the post itself, and getting that to validate. For that, each step should have its own view model, containing only the properties it's supposed to modify. This allows you to add all the validation you need without causing other steps to fail. In the end, you'll combine the data from all of these into your entity class or whatever.
Which brings us to the second piece. You need some way of persisting the data from each step. The only data that will exist after a POST is the data that was posted and anything in the session (which includes TempData). You could always create a bunch of hidden fields to store the data from the previous steps, but that can get a little arduous. Most likely, you'll just want to use the session.
TempData is basically a specialized instance of Session, so which you use doesn't really matter. With TempData, you'll need to remember call TempData.Keep() for each of the keys you've set for each step or you'll lose the previous steps on the next request. Session will keep them around for the life of the session, but you should remember to remove the keys at the end with Session.Remove().
Do you use #using (Html.BeginForm()) in your .cshtml?
Unfortunately this is MVC. MVC is stateless, which means if you don't render it then you loose it :(
If you use model binding and scaffolding, then you can save some time and work but at the end it will be the same solution.
I am very new to asp.net development. In my asp.net mvc project I have model "Employee" and I'm passing a list of "Employee" model to a RAZOR view and I'm trying to count different type of employees and show a summary.
my view is like this,
#{
int available = 0;
int onLeave = 0;
int away = 0;
int unAvailable = 0;
}
#foreach (var employee in Model){
<lable>#employee.Name</lable></br>
#if (#employee.Available){
#available=available+1;
}
#if (#employee.Unavailable){
#unAvailable=unAvailable;
}
#if (#employee.Away){
#away=away+1;
}
#if (#employee.Onleave){
#onLeave=onLeave+1;
}
}
<div>
<!--additional summary is displayed here-->
<label>Available:</label>#available
<label>Unavailable:</label>#unAvailable
<label>Away:</label>#away
<label>On Leave:</label>#onLeave
</div>
but when I run the my project variables "available","unAvailable","away" and "onLeave" don't get updated.
I'm sure that list is not empty because employee names are displaying.
can some explain me what is happening here and correct way of doing this
You should be doing this outside the before passing to the view like I mentioned in my original comment. You can create a new object called a ViewModel to represent the data exactly like you want it on the page. So I created a simple example, I only used the 4 properties of Employee you are displaying in you CSHTML page. On your View where you said your MODEL is either a list, arrary or whatever of Employee change it to EmployeeViewModel. Then in your controller where you get your list of employees set them to the Employees property of the Employee ViewModel.
public class EmployeeViewModel
{
public IEnumerable<Employee> Employees { get; set; }
public int TotalAvailable { get { return Employees.Count(emp => emp.Available); } }
public int TotalUnavailable { get { return Employees.Count(emp => emp.Unavilable); } }
public int TotalAway { get { return Employees.Count(emp => emp.Away); } }
public int TotalOnLeave { get { return Employees.Count(emp => emp.OnLeave); } }
}
public class Employee
{
public bool Available { get; set; }
public bool Unavilable { get; set; }
public bool Away { get; set; }
public bool OnLeave { get; set; }
}
//In the controller do this.
public ActionResult Index() //use your controller Action Name here
{
var employeeViewModel = new EmployeeViewModel { Employees = /*Your list of empoyees you had as a Model before here*/}
return View(employeeViewModel)
}
Change your CSHTML code to something like this:
#foreach(var employee in Model.Employees)
{
<label> #employee.Name </label></br>
}
<div>
<!--additional summary is displayed here-->
<label> Available:</label> #Model.TotalAvailable
<label> Unavailable:</label> #Model.TotalUnavailable
<label> Away:</label> #Model.TotalAway
<label> On Leave:</label> #Model.TotalOnLeave
</div>
An easy and quick way is:
<div>
<!--additional summary is displayed here-->
<label>Available:</label>#Model.Count(i => i.Available)<br>
<label>Unavailable:</label>do the same.
<label>Away:</label>do the same.
<label>On Leave:</label>do the same.
</div>
Make sure the model has already been "ToList()", or it might lead to mult-access of database.
Basically, I only use viewmodel when I need to pass more than 1 models to the view. Not worth in this case.
Make such calculations in View considered a BAD practice.
In your case better option will be create ViewModel with corresponding properties and then pass it to the model, previously calculating count for every type in controller using LINQ. Where you could reference your types like Model.available, Model.away and so on. Using ViewModel it is the best practice for MVC.
#Thorarins answer show you how to use LINQ in your code to calculate count for you types.
UPDATE:
You can use JS, but you should not, because it still not what supposed to happen in View. Work with data should not be handled in View. Don't be scared by ViewModels, they not that hard as it could seem. Please read this article which consider all ways to pass data to View, which has good example how create and pass ViewModel.
Mvc sample on how to do it:
you need a model class
public class EmployeeModel
{
public int Available {get; set;}
public int OnLeave {get; set;}
public int Away {get; set;}
public int UnAvailable {get; set;}
}
and a command:
public ActionResult Index()
{
var model = new EmployeeModel();
model.Available = employee.count(e=> e.available);
model.OnLeave = employee.count(e=> e.onLeave);
model.Away = employee.count(e=> e.away);
model.UnAvailable = employee.count(e=> e.unAvailable );
return View(model);
}
and a view
#model EmployeeModel
<div>
<!--additional summary is displayed here-->
<label>Available:</label>#Model.Available
<label>Unavailable:</label>#Model.UnAvailable
<label>Away:</label>#Model.Away
<label>On Leave:</label>#Model.OnLeave
</div>
I have a view model in my ASP.NET MVC app that holds a List of objects. Each of these objects are visualized using EditorTemplate. Using a dropdown I can add dynamically new object to the List on postback. The problem is when I try to remove a specific element from the list.
public class MyViewModel
{
public List<MyModel> Items { get; set; }
public MyViewModel()
{
this.Items = new List<MyModel>();
}
}
public class MyModel
{
public int Id { get; set; }
public string Text { get; set; } // I bind this to UI using EditorFor html helper
}
HomeController:
[HttpPost]
public ActionResult Index(MyViewModel myViewModel)
{
myViewModels.Items.Add(new MyModel()); // Simulate initializing the Id and Text properties
return View(myViewModel);
}
Then in Index.cshtml:
if (Model.Items != null)
{
#Html.EditorFor(m => Model.Items); // EditorTemplate is used here...
}
So in my template file, called Item.cshtml I have:
#model MVCApp.Models.MyModel
<div>
#Html.HiddenFor(m => m.Id)
#Html.EditorFor(m => m.Text)
<span class="deleteItem" data-item-id="#Model.Id">Delete</span>
</div>
Now I don't know how to process the deletion of the specific item when I click on "Delete". My goal is to have the item deleted from the collection in the controller ('Items' list property of the view model). I can delete the div element using jQuery but the property would not be removed from the 'Items' collection and I would like to avoid jQuery to preserve data integrity between server and client side. I tried to call another action in HomeController called Remove(int? id) where the id parameter is the Id property of 'MyModel', but I need to pass 'MyViewModel' object in Remove action in order to access the 'Items' list, remove the element and then redirect to 'Index' action with the changed collection. How can I achieve that? Thanks!
Update
If you are looking to do it using. You can submit form using submit button and pass in the id to remove and then calling controller action and code accordingly.
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})