I'm trying to create a very basic MVC app based on a tutorial. I am using the default routing, and simple Views and Model.
The problem I am having is with the HttpPost Edit function. I am expecting an object of my "MyObject" type to be passed as the parameter, but it always comes back null.
Here are my Edit functions from the controller (the Get function works properly):
public ActionResult Edit(int? id)
{
if (!id.HasValue)
return RedirectToAction("Index");
var item = (from obj in mDB.MyDatabaseObjects
where obj.Id == id
select obj).First();
return View(item);
}
//
// POST: /Main/Edit/5
[HttpPost]
public ActionResult Edit(MyDatabaseObject someObject)
{
var original = (from obj in mDB.MyDatabaseObjects
where obj.Id == someObject.Id
select obj).First();
if (!ModelState.IsValid)
return View(original);
mDB.ApplyCurrentValues(original.EntityKey.EntitySetName, someObject);
mDB.SaveChanges();
return RedirectToAction("Index");
}
Note that my (nearly identical) Create method works as expected:
[HttpPost]
public ActionResult Create([Bind(Exclude="Id")] MyDatabaseObject newObject)
{
if (!ModelState.IsValid)
return View();
int max = mDB.MyDatabaseObjects.Max(data => data.TaskOrder);
newObject.TaskOrder = max + 1;
mDB.AddToMyDatabaseObjects(newObject);
mDB.SaveChanges();
return RedirectToAction("Index");
}
Thanks,
wTs
Ensure the values on your view for MyDatabaseObject are inside of the form. Validate these values are being posted over - inspect Request.Form or use change the method signature to use
FormsCollection collection
simply to validate the values are getting posted. If its choosing that method - it should be matching the properties to the form field - its generally very simple.
Related
how can i send data between actions with redirectAction??
I am using PRG pattern. And I want to make something like that
[HttpGet]
[ActionName("Success")]
public ActionResult Success(PersonalDataViewModel model)
{
//model ko
if (model == null)
return RedirectToAction("Index", "Account");
//model OK
return View(model);
}
[HttpPost]
[ExportModelStateToTempData]
[ActionName("Success")]
public ActionResult SuccessProcess(PersonalDataViewModel model)
{
if (!ModelState.IsValid)
{
ModelState.AddModelError("", "Error");
return RedirectToAction("Index", "Account");
}
//model OK
return RedirectToAction("Success", new PersonalDataViewModel() { BadgeData = this.GetBadgeData });
}
When redirect you can only pass query string values. Not entire complex objects:
return RedirectToAction("Success", new {
prop1 = model.Prop1,
prop2 = model.Prop2,
...
});
This works only with scalar values. So you need to ensure that you include every property that you need in the query string, otherwise it will be lost in the redirect.
Another possibility is to persist your model somewhere on the server (like a database or something) and when redirecting only pass the id which will allow to retrieve the model back:
int id = StoreModel(model);
return RedirectToAction("Success", new { id = id });
and inside the Success action retrieve the model back:
public ActionResult Success(int id)
{
var model = GetModel(id);
...
}
Yet another possibility is to use TempData although personally I don't recommend it:
TempData["model"] = model;
return RedirectToAction("Success");
and inside the Success action fetch it from TempData:
var model = TempData["model"] as PersonalDataViewModel;
You cannot pass data between actions using objects, as Darin mentioned, you can only pass scalar values.
If your data is too large, or does not consist only of scalar values, you should do something like this
[HttpGet]
public ActionResult Success(int? id)
{
if (!(id.HasValue))
return RedirectToAction("Index", "Account");
//id OK
model = LoadModelById(id.Value);
return View(model);
}
And pass that id from RedirectToAction
return RedirectToAction("Success", { id = Model.Id });
RedirectToAction method returns an HTTP 302 response to the browser, which causes the browser to make a GET request to the specified action. So you can not pass complex objects like you calling other methods with complex objects.
Your possible solution is to pass an id using with the GET action can build the object again. Some thing like this
[HttpPost]
public ActionResult SuccessProcess(PersonViewModel model)
{
//Some thing is Posted (P)
if(ModelState.IsValid)
{
//Save the data and Redirect (R)
return RedirectToAction("Index",new { id=model.ID});
}
return View(model)
}
public ActionResult Index(int id)
{
//Lets do a GET (G) request like browser requesting for any time with ID
PersonViewModel model=GetPersonFromID(id);
return View(id);
}
}
You can keep data (The complex object) between This Post and GET request using Session also (TempData is internally using session even). But i believe that Takes away the purity of PRG Pattern.
Actually I'm very new to ASP.NET MVC and I need your help.
Here I have some Create Method that takes an argument from the URL to use it as id:
in 'vote' controller :
public ActionResult Create(int id)
{
Meeting meeting = db.Meetings.Find(id); // get the object
ViewBag.meetingID = meeting.meetingID; // get its id and assign it to a ViewBag
return View();
}
and I would like to do something like :
vote.meetingID = #ViewBag.meetingID
in the model so that is directly assgin this property without excplicitely typing it from the HTML view (I mean #Html.EditorFor(model=>meetingID) )
The question is not that clear, but try this.
You could pass the entire model to the view.
Controller:
public ActionResult Create(int id)
{
Meeting meeting = db.Meetings.Find(id); // get the object
ViewData["myMeeting"] = meeting;
return View();
}
To use in the view you can declare it as a variable at the top of the view:
Declare:
#
{
var meetingData = ViewData["myMeeting"] as Meeting;
}
Usage:
<div>
#meetingData.meetingID
</div>
If I have the usual Edit actions, one for GET to retrieve an object by it's ID and to display it in an edit form. The next for POST to take the values in the ViewModel and update the object in the database.
public virtual ActionResult Edit(int id)
[HttpPost]
public ActionResult Edit(VehicleVariantEditSaveViewModel viewModel)
If an error occurs during model binding in the POST action, I understand I can RedirectToAction back to the GET action and preserve the ModelState validation errors by copying it to TempData and retrieving it after the redirect in the GET action.
if (TempData["ViewData"] != null)
{
ViewData = (ViewDataDictionary)TempData["ViewData"];
}
How do I then convert that ViewData, which includes the previous invalid ModelState, into a new model to send to the view so the user sees their invalid input with validation warnings? Oddly enough if I pass in a new instance of my ViewModel retrieved from the database (with the original valid data) to the View() this is ignored and the (invalid) data in the ViewData is displayed!
Thanks
I had a similar problem and decided to use the following pattern:
public ActionResult PersonalRecord(Guid id)
{
if (TempData["Model"] == null)
{
var personalRecord = _context.PersonalRecords.Single(p => p.UserId == id);
var model = personalRecord.ToPersonalRecordModel();
return View(model);
}
else
{
ViewData = (ViewDataDictionary) TempData["ViewData"];
return View(TempData["Model"]);
}
}
[HttpPost]
public ActionResult PersonalRecord(PersonalRecordModel model)
{
try
{
if (ModelState.IsValid)
{
var personalRecord = _context.PersonalRecords.Single(u => u.UserId == model.UserId);
personalRecord.Email = model.Email;
personalRecord.DOB = model.DOB;
personalRecord.PrimaryPhone = model.PrimaryPhone;
_context.Update(personalRecord);
_context.SaveChanges();
return RedirectToAction("PersonalRecord");
}
}
catch (DbEntityValidationException ex)
{
var errors = ex.EntityValidationErrors.First();
foreach (var propertyError in errors.ValidationErrors)
{
ModelState.AddModelError(propertyError.PropertyName, propertyError.ErrorMessage);
}
}
TempData["Model"] = model;
TempData["ViewData"] = ViewData;
return RedirectToAction("PersonalRecord", new { id = model.UserId });
}
Hope this helps.
I noticed that the Model is included in ViewData so you don't need to pass it in addition to the ViewData, what I don't understand is how you get at it to then return it to the view.
public ViewResult Edit(int id)
{
// Check if we have ViewData in the session from a previous attempt which failed validation
if (TempData["ViewData"] != null)
{
ViewData = (ViewDataDictionary)TempData["ViewData"];
}
VehicleVariantEditViewModel viewModel = new VehicleVariantControllerViewModelBuilder()
.BuildForEdit(id);
return View(viewModel);
}
The above works but obviously it's making an unnecessary call to the database to build a new Model (which gets automagically overwritten with the invalid values from the Model in the passed ViewData)
Confusing.
I'm a beginner of MVC3 with ASP.Net (C#) but I don't get the next situation to delete a record.
I have a View that ask the user to confirm delete a item (record). As code I have this to initialize the view:
public ActionResult KeywordsDelete(Guid id)
{
_db = new BlaContext();
return _db.SearchTerms.Where(x => x.id.Equals(id)).First();
}
But when confirmed, then I have the next code.
[HttpPost]
public ActionResult KeywordsDelete(Guid id)
{
_db = new BlaContext();
var term = _db.SearchTerms.Where(x => x.id == id).First();
_db.SearchTerms.Remove(term);
_db.SaveChanges();
return View("Keywords", _db.SearchTerms.ToList());
}
Building is not possible because the signature of this method is already exists (same parameters and method name).
So I don't get how to delete a record in this situation. The view is created with a default Scaffold template (delete).
I found an alternative solution to this problem while reading up on MVC. Check out: Improving the Details and Delete Methods
[HttpPost, ActionName("Delete")]
public ActionResult DeleteConfirmed(int id = 0)
{
// Delete stuff...
}
This will route the action Delete to the method DeleteConfirmed.
You can give your post function another additional parameter
[HttpPost]
public ActionResult KeywordsDelete(Guid id, FormCollection collection)
{
_db = new BlaContext();
var term = _db.SearchTerms.Where(x => x.id == id).First();
_db.SearchTerms.Remove(term);
_db.SaveChanges();
return View("Keywords", _db.SearchTerms.ToList());
}
But your GET Action should also return a View not a data object, I think.
public ActionResult KeywordsDelete(Guid id)
{
_db = new BlaContext();
return View(_db.SearchTerms.Where(x => x.id.Equals(id)).First());
}
Trying to get my ducks in a row with MVC3 + Razor!
I finally understand the concept of a 'View-Model' to wrap my entity classes and tailor them to a View.
Now I'm assembling a page with partial views representing different elements necessary to the page (such as drop down lists, forms, etc.) each of these will be represented by a 'View-Model' that maps to an entity class and back to my database.
First I am trying to create a partial view representing a component that is a drop-down list of elements in the database, that when selected will render another partial view, etc.
I just can't put together why I can't generate this drop-down list, and once I do how the main 'controller' maps all this together?
In short I'm curious - does each partial view need a controller even if it's based on a strongly typed model?
Breaking it down:
My Entity Model-View Wrapper (getting all the elements available from the database
*Updated* - to a working example now, note I don't think I was asking the right question before, but this will give you an idea of what I was trying to accomplish! Next step is to move all these operations 'off' the controller (and populate them in the models default constructor, for ease of use later).
CharactersListViewModel.cs
Going to move avoid the 'View Model' for now until I get a little more comfortable
Creating a partial view that displays a drop down list with the Characters' ID as a value, and name as the text, create strongly-typed view, partial view
controller for main-page in section:
HistoryController.cs
public class HistoryController : Controller
{
public ActionResult Index()
{
var list = new List<SelectListItem>();
using (var _database = new fff_newEntities())
{
foreach(Character c in (from c in _database.Characters select c)){
list.Add(new SelectListItem(){Text = c.CharacterName, Value = c.Id.ToString()});
}
}
ViewBag.Clients = list;
}
}
//
// GET: /History/Details/5
public ActionResult Details(int id)
{
return View();
}
//
// GET: /History/Create
public ActionResult Create()
{
return View();
}
//
// POST: /History/Create
[HttpPost]
public ActionResult Create(FormCollection collection)
{
try
{
// TODO: Add insert logic here
return RedirectToAction("Index");
}
catch
{
return View();
}
}
//
// GET: /History/Edit/5
public ActionResult Edit(int id)
{
return View();
}
//
// POST: /History/Edit/5
[HttpPost]
public ActionResult Edit(int id, FormCollection collection)
{
try
{
// TODO: Add update logic here
return RedirectToAction("Index");
}
catch
{
return View();
}
}
public ActionResult Delete(int id)
{
return View();
}
//
// POST: /History/Delete/5
[HttpPost]
public ActionResult Delete(int id, FormCollection collection)
{
try
{
// TODO: Add delete logic here
return RedirectToAction("Index");
}
catch
{
return View();
}
}
The index to display the whole page including the partial component (my drop down list)
index.cshtml:
#{
ViewBag.Title = "Index";
}
<h2>Index</h2>
#Html.DropDownListFor(x => x.CurrentCharacterId, (IEnumerable<SelectListItem>)ViewBag.Clients);
On the last line here, #Html.Action(...) where do I actually create the drop-down list?
Sorry if this seems trivial but I can't wrap my head around it and I really want to learn MVC3 + Razor correctly!
A partial view is meant to abstract out some HTML/View Logic so that it can be re-used either in multiple places or for repeating (looping).
Though you can have an action that maps to the partial and if the partial in question does some explicit data access this might be the way to go but if you're just passing down all the data it needs from the controller itself then - no, you don't need a Controller/Action for it.
Since you're doing some explicit data access I would probably make an action for it...
[ChildActionOnly]
public ActionResult Characters()
{
using (var _database = new entities())
{
CharactersViewModel viewModel = new CharactersViewModel();
viewModel.Characters = _database.Characters.ToDictionary(c => c.Id, c => c.CharacterName);
return PartialView(viewModel);
}
}
In your view...
#Html.Action("Characters")
Of course there's nothing wrong with the way you're doing it but I find having it map to an action can make things easier down the road if you ever wanted to retrieve the HTML from this rendered partial view via an ajax request or something of the sort.
Notes:
Try to wrap your entity context object in a using so it can dispose of the connection.
You can use ToDictionary to select your dictionary directly from the query scope.