I am allowing users to upload a file from the view which will eventually be passed to the model through controller actions. However, there is a particular situation that is giving me trouble.
I have the followong ViewModel that I'm passing to the view:
public class RegisterStudentViewModel
{
public Login loginViewModel;
public Person personViewModel;
public PersonResume personResViewModel;
}
When the form is submitted, I use some validation logic to make sure the fields entered were applicable, and if any of the validation fails, I send the ViewModel that I'm using back to the view, to make sure that the fields that had information entered correctly are stored. Before this though, I have also made sure that the file uploaded is binded to the model that it belongs to, like this:
if (res != null)
{
PersonResume resumeViewModel = createResume(res, personModel);
vm.personResViewModel = resumeViewModel;
}
SetUpView(vm, da);
result = View(vm);
}
so that when the validation fails but the resume wasn't one of the fields that failed and I want to display the uploaded resume, I can use the following code in my view:
#if (Model.personResViewModel != null && Model.personViewModel.id == 0)
{
<th class="editAddLabel">
#Html.LabelFor(model => model.personResViewModel.ResumeFileName, "Resume File Name")
</th>
<td>
#Html.ActionLink("View your resume", "linkDownload", "Student", new { id = Model.personViewModel.id, resume = Model.personResViewModel}, null)
</td>
}
to pass to the following controller method that will allow the link to be downloaded:
public FileResult linkDownload(int id, PersonResumeViewModel resume)
{
DataAccess da = new DataAccess();
PersonResume displayResume = new PersonResume();
if (id != 0)
{
displayResume = da.getPersonResumeByID(id);
}
else
{
displayResume.ResumeData = resume;
}
//some more code that downloads file
}
I know that in the view, the personResViewModel is not null, but when I look at the controller method, it is null and I can't do anything with it. Am I not passing my argument in correctly?
Related
I am building a mail system where at every page that you land you will get a notification that you have unread mail.
As this needs to be on every page, I thought that I should probably then just add functionality to Base Controller and have the function called that way as every controller I have will be extended of my Base Controller.
As such in my base controller I have the following function which will get me the number of unread invitations this user has:
public void GetUnreadInvitationCount(string userId)
{
var count = Db.Request.Where(r => r.ReceiverId == userId && r.DateLastRead == null).Count();
if (count > 0) ViewBag.UnreadInvitations = count;
}
Then in my constructor I tried the following:
public class BaseController : Controller
public BaseController()
{
if (User != null && User.Identity != null && User.Identity.IsAuthenticated)
{
GetUnreadInvitationCount(User.Identity.GetUserId());
}
}
}
The problem is that the User is null as it has not been instantiated.
How do I get around this? How do I make a common functionality such as this be on every page and not have to repeat my code on every controller specifically?
I have thought of few solutions myself, but none of these seem to be the right way to go.
Option 1: Create a BaseViewModel which will be called in every page that has this value, this would mean I have to instantiate the method in every action on the website, but at least the code is common for it if I ever need to update it.
Option 2: Do not do this on the server side but setup an ajax script to be called after the page has loaded. This would have an initial delay but it would work.
Does anyone has a different solution?
EDIT - For JohnH:
I have tried solution suggested by john, here is the code:
_Layout.cshtml
#{ Html.RenderAction("GetUnreadInvitationCount", "Base");}
BaseController.cs
public ActionResult GetUnreadInvitationCount()
{
string userId = User.Identity.GetUserId();
var count = Db.Request.Where(r => r.ReceiverId == userId && r.DateLastRead == null).OrderByDescending(r => r.Id).Count();
BaseViewModel model = new BaseViewModel {RequestCount = count};
return View("UnreadInvitations", model);
}
UnreadInvitations.cshtml
#model Azularis.System.Events.Models.ViewModels.BaseViewModel
#if (#Model.RequestCount > 0)
{
<li>
#Html.ActionLink("Mail", "Index", "Teams", null, new { #class = "mail-image" })
#Html.ActionLink(#Model.RequestCount.ToString(), "Index", "Teams", null, new { #class = "mail-number" })
</li>
}
However this forces me into a loop where _Layout.cshtml is constantly repeating until the page crashes with
The context cannot be used while the model is being created. This exception may be thrown if the context is used inside the OnModelCreating method or if the same context instance is accessed by multiple threads concurrently. Note that instance members of DbContext and related classes are not guaranteed to be thread safe.
Does anyone knows why it constantly loops?
As discussed in the comments above, the real issue here is not that the code should be shared amongst various controllers, it's that you want a common point in which to run your particular piece of code. In that sense, it lends itself to being abstracted out into a separate controller, which centralises all invitation logic in one place, leading to better separation of concerns. You can then invoke those actions either in your _Layout.cshtml view, or in any other views if need be.
Using the code in your answer as an example (thanks for that):
InvitationController:
public ActionResult GetUnreadInvitationCount()
{
string userId = User.Identity.GetUserId();
var count = Db.Request.Where(r => r.ReceiverId == userId && r.DateLastRead == null).OrderByDescending(r => r.Id).Count();
BaseViewModel model = new BaseViewModel {RequestCount = count};
return View("UnreadInvitations", model);
}
InvitationController\UnreadInvitations.cshtml:
#if (Model.RequestCount > 0)
{
// Render whatever you need to display the notification
}
Then finally, in your _Layout.cshtml, somewhere, you would invoke this action by calling:
#{ Html.RenderAction("GetUnreadInvitationCount", "Invitation"); }
It's important to note that you may need to use #{ Layout = null; } in the child view being rendered, otherwise it will default to rendering _Layout.cshtml again... which in turn renders the action again... then calls the child view again... and so on. :) Setting the layout to null will prevent that from happening.
Edit: Actually, the reason the _Layout.cshtml file is being called again is because we're returning a ViewResult from the action. Change that to a PartialViewResult and you no longer need the #{ Layout = null; }. Thus:
return View("UnreadInvitations", model);
becomes:
return PartialView("UnreadInvitations", model);
User property is null because it is set after constructor is invoked. However, you do not have to do your logic in the constructor. The following should be placed in your BaseController.
protected int? GetUserId()
{
return (User != null && User.Identity != null && User.Identity.IsAuthenticated) ? User.Identity.GetUserId() : null;
}
protected void GetUnreadInvitationCount()
{
int? userId = GetUserId();
if (userId == null)
throw new SecurityException("Not authenticated");
var count = Db.Request.Where(r => r.ReceiverId == userId.value && r.DateLastRead == null).Count();
if (count > 0) ViewBag.UnreadInvitations = count;
}
GetUnreadInvitationCount is called after User is initialized (I guess when some controller action is gets called) and can use GetUserId from the BaseController.
I have a problem transfering data from one view to another via the controler actions.
I the first view is a grid.mvc-Grid displayed. By select on row of the grid I get the ID for that object.
by transfering this to an action in the controler I try to filter the data. That works fine.
Here is the filter:
[HttpGet]
public ActionResult PersonenById(int id)
{
var personen = new ObservableCollection<Person>();
//Getting the data here :-)
foreach (DataRow r in access.Rows)
{
Person p = new Person();
//do some stuff
personen.Add(p);
}
//return PartialView("Personen", personen); //does not work
TempData["personen"] = personen;
return RedirectToAction("Personen"); // redirect to another view
}
In method II the view is filled:
public ActionResult Personen()
{
var persons = new ObservableCollection<Person>();
if (TempData["Persons"] == null)
{
}
return View(persons); //Works perfect
}
else
{
persons = (ObservableCollection<Person>) TempData["Persons"];
return View(persons);//does not redirect to that View
}
}
(Sorry for the strange formating. :-))
Is there any different way to send data from a view to another?
I tried:
return partial;
return View("Persons",persons);
and a lot other stuff.
You can redirect in a .cshtml view.
Eg:
Context.Response.StatusCode = 403;
Context.Response.Redirect(
$"{Context.Request.PathBase}/Error/403", false);
Should work like this:
return RedirectToAction("Personen", model);
Also, the "Personen" action should have the model as an argument, like this:
public ActionResult Personen(Person model) ...
LE: I have also noticed you have tried to send the data through the TempData object. Make sure the indexed object's name is the same (e.g. TempData["person"] everywhere)
Hope it answers your question.
This is now fixed. A combination of Ish's suggestion below plus adding calls to #HiddenFor in the view resolved the problem.
I have an ASP.NET MVC 5 web application where users can mark a defect as resolved. I want to display a list of potentially related defects, with check-boxes that users can tick to indicate that yes, this is the same defect, and should also be marked as resolved.
So I have a View Model with a property that is a collection, each member of which contains a defect object property and Boolean IsSameDefect property. This all works fine in the GET action method and in the view. I can display the related defects and tick the boxes.
The problem arises in the POST action when I want to update the data. At this point the property (the collection of potentially related defects) is null. I'm having a hard time trying to figure out how to pass this data back to the controller?
Code as requested ...
// GET: /DefectResolution/Create
public ActionResult Create(int ciid)
{
int companyId = User.CompanyID();
DefectResolutionCreateViewModel drcvm = new DefectResolutionCreateViewModel(ciid, companyId);
return View(drcvm);
}
// POST: /DefectResolution/Create
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(DefectResolutionCreateViewModel drcvm)
{
DefectResolutions currentResolution = drcvm.DefectResolution;
currentResolution.CreatedOn = System.DateTime.Now;
currentResolution.UserID = User.UserID();
if (ModelState.IsValid)
{
unitOfWork.DefectResolutionRepository.Insert(currentResolution);
if (currentResolution.ResolutionStatusID == 2)
{
//code breaks here as drcvm.RelatedUnresolvedDefects is null
foreach (var relatedDefect in drcvm.RelatedUnresolvedDefects)
{
if (relatedDefect.IsSameDefect)
{
DefectResolutions relatedResolution = new DefectResolutions();
relatedResolution.ChecklistID = relatedDefect.RelatedChecklist.ChecklistID;
relatedResolution.CreatedOn = System.DateTime.Now;
relatedResolution.ResolutionNote = currentResolution.ResolutionNote;
relatedResolution.ResolutionStatusID = currentResolution.ResolutionStatusID;
relatedResolution.UserID = User.UserID();
}
}
}
unitOfWork.Save();
return RedirectToAction("Index", new { ciid = currentResolution.ChecklistID });
}
return View(drcvm);
}
In the view ...
#model Blah.ViewModels.DefectResolution.DefectResolutionCreateViewModel
#{
ViewBag.Title = "Create Defect Resolution";
var relatedDefects = Model.RelatedUnresolvedDefects;
}
... and later in the view ...
#for (int i = 0; i < relatedDefects.Count(); i++ )
{
<tr>
<td>
#Html.EditorFor(x => relatedDefects[i].IsSameDefect)
</td>
</tr>
}
I followed Ish's suggestion below, and modified the code to refer to Model.RelatedUnresolvedDefects directly instead of using a variable as I had been doing. This does get me a bit further. The view model's RelatedUnresolvedDefects property is no longer null. But only RelatedUnresolvedDefects.IsSameDefect has a value. RelatedUnresolvedDefects.RelatedChecklist is null. Here's the controller code again showing where it now breaks ...
// POST: /DefectResolution/Create
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(DefectResolutionCreateViewModel drcvm)
{
DefectResolutions currentResolution = drcvm.DefectResolution;
currentResolution.CreatedOn = System.DateTime.Now;
currentResolution.UserID = User.UserID();
if (ModelState.IsValid)
{
unitOfWork.DefectResolutionRepository.Insert(currentResolution);
if (currentResolution.ResolutionStatusID == 2)
{
//prior to change, code used to break here
foreach (var relatedDefect in drcvm.RelatedUnresolvedDefects)
{
if (relatedDefect.IsSameDefect)
{
DefectResolutions relatedResolution = new DefectResolutions();
//code now breaks here because relatedDefect.RelatedChecklist is null
relatedResolution.ChecklistID = relatedDefect.RelatedChecklist.ChecklistID;
relatedResolution.CreatedOn = System.DateTime.Now;
relatedResolution.ResolutionNote = currentResolution.ResolutionNote;
relatedResolution.ResolutionStatusID = currentResolution.ResolutionStatusID;
relatedResolution.UserID = User.UserID();
}
}
}
unitOfWork.Save();
return RedirectToAction("Index", new { ciid = currentResolution.ChecklistID });
}
return View(drcvm);
}
Without knowing your code.I suggest you to use for loop instead of foreach while rendering the defects in View (.cshtml).
Editing Answer based on your code.
Following statement in the view creating problem
var relatedDefects = Model.RelatedUnresolvedDefects;
You should directly iterate over the Model.RelatedUnresolvedDefects property in the loop.
#for (int i = 0; i < Model.RelatedUnresolvedDefects.Count(); i++ )
{
<tr>
<td>
#Html.EditorFor(x => Model.RelatedUnresolvedDefects[i].IsSameDefect)
</td>
</tr>
}
I'm using MVC 4 with Razor Syntax to create a collection based on a class that was created using scaffolding (Database first based development) and I can add the first collection to the Session and return it to the Index view and display it on the page.
When I attempt to add a second collection to the Session Variable it gives me a error.
Unable to cast object of type
'System.Collections.Generic.List`1[EagleEye.Models.tblTask]' to type
'EagleEye.Models.tblTask'.
What am I doing wrong - how do I add 2 collections to the session?!
Index.cshtml (My Index view using Razor syntax)
#model List<myApp.Models.tblTask>
<table>
#{
foreach (var tblTask in Model)
{
<tr>
<td>
TaskName: #tblTask.Name
</td>
<td>
Desc: #tblTask.Description
</td>
<td>
Schedule: #tblTask.Freq #tblTask.FreqUnit
</td>
<td>
Reocurring?: #tblTask.ReocurringTask.ToString()
</td>
</tr>
}
}
</table>
Here's the "ActionResult" portion of the code from my HomeController.cs:
[HttpPost]
public ActionResult CreateTask(tblTask newTask)
{
var TaskCollection = new List<tblTask>();
if (Session["TaskCollection"] != null)
{
TaskCollection.Add((tblTask)Session["TaskCollection"]);
}
TaskCollection.Add(newTask);
Session["TaskCollection"] = TaskCollection;
return RedirectToAction("Index");
}
public ActionResult Index()
{
var TaskCollection = new List<tblTask>();
if (Session["TaskCollection"] != null)
{
TaskCollection = (List<tblTask>)Session["TaskCollection"];
}
return View(TaskCollection);
}
When I add the first entry it works fine and shows up on my index view. When I try to add the second collection of tasks, it tells me:
Unable to cast object of type
'System.Collections.Generic.List`1[EagleEye.Models.tblTask]' to type
'EagleEye.Models.tblTask'.
I've been fighting this for a few days now and have been developing for a while, but am just beginning to learn the power of asking questions when I'm stumped (instead of just continuing to beat my head against the wall until something caves in (often my head), so if my question is not well formed, please let me know.
Thanks!
Dan
Because, inside your if condition, you are casting the Session["TaskCollection"](which is a collection of tblTask to a single instance of tblTask.
This should work.
[HttpPost]
public ActionResult CreateTask(tblTask newTask)
{
var TaskCollection = new List<tblTask>();
//Check whether the collection exist in session, If yes read it
// & cast it to the tblTask collection & set it to the TaskCollection variable
if (Session["TaskCollection"] != null)
{
TaskCollection= (List<tblTask>) Session["TaskCollection"];
}
if(newTask!=null)
TaskCollection.Add(newTask);
//Set the updated collection back to the session
Session["TaskCollection"] = TaskCollection;
return RedirectToAction("Index");
}
I finally see the light -- Note the change in the HomeController.cs "TaskCollection = (List)Session["TaskCollection"]; "
[HttpPost]
public ActionResult CreateTask(tblTask newTask)
{
var TaskCollection = new List<tblTask>();
if (Session["TaskCollection"] != null)
{
//Here is the line that changed -- the following line works~
TaskCollection = (List<tblTask>)Session["TaskCollection"];
}
TaskCollection.Add(newTask);
Session["TaskCollection"] = TaskCollection;
return RedirectToAction("Index");
}
I have been introduced to Razor as applied with MVC 3 this morning, so please forgive me if my question seems terribly uninformed!
I am working with an app whose workflow involves allowing a user to select a value (warehouse) from a drop down list, and add a record (material) from that warehouse to another record (Materials Request). Once the first material has been added to the Materials Request, I need to permanently set the value of the drop down to the warehouse that was first selected, then disable the drop down control (or set to read only, perhaps). The existing code in the razor file uses the DropDownListFor() method, including a ViewBag collection of Warehouse records. I have seen discussions which suggest abandoning the ViewBag design, but honestly I don't have the desire to rewrite major portions of the code; at least it looks like a major rewrite from the perspective of my experience level. Here's the original code:
#Html.LabelPlusFor(m => m.WarehouseId, "*:")
#Html.DropDownListFor(m => m.WarehouseId, (IEnumerable<SelectListItem>)ViewBag.WarehouseCodes, "")<br />
I believe I have been able to select a value based on a session object, though I'm still not sure how to disable the control. Here's my change:
#{
int SelectedWarehouseId = -1;
if (HttpContext.Current.Session["SelectedWarehouseId"] != null)
{
SelectedWarehouseId = Int32.Parse(HttpContext.Current.Session["SelectedWarehouseId"].ToString());
}
}
#Html.LabelPlusFor(m => m.WarehouseId, "*:")
#{
if (SelectedWarehouseId > -1)
{
#Html.DropDownListFor(m => m.WarehouseId, new SelectList((IEnumerable<SelectListItem>)ViewBag.WarehouseCodes, "WarehouseId", "WarehouseDescription", (int)SelectedWarehouseId))<br />
}
else
{
#Html.DropDownListFor(m => m.WarehouseId, (IEnumerable<SelectListItem>)ViewBag.WarehouseCodes, "")<br />
}
}
When the material is added to the Material Request, the WarehouseId is passed to the controller and I can access that value as "model.WarehouseId" in the controller class. However, I'm not sure how to get that value back to the View (apologies for the large code block here):
[HttpPost]
[TmsAuthorize]
public ActionResult Create(ItemRequestViewModel model)
{
string deleteKey = null;
//Removed code
else if (Request.Form["AddToRequest"] != null)
{
// If the user clicked the Add to Request button, we are only
// interested in validating the following fields. Therefore,
// we remove the other fields from the ModelState.
string[] keys = ModelState.Keys.ToArray();
foreach (string key in keys)
{
if (!_addToRequestFields.Contains(key))
ModelState.Remove(key);
}
// Validate the Item Number against the database - no sense
// doing this if the ModelState is already invalid.
if (ModelState.IsValid)
{
_codes.ValidateMaterial("ItemNumber", model.ItemNumber, model.WarehouseId);
Session["SelectedWarehouseId"] = model.WarehouseId;
}
if (ModelState.IsValid)
{
// Add the new Item Request to the list
model.Items.Add(new ItemViewModel() { ItemNumber = model.ItemNumber, Quantity = model.Quantity.Value, WarehouseId = model.WarehouseId });
ModelState.Clear();
model.ItemNumber = null;
model.Quantity = null;
model.WarehouseId = null;
}
}
//Removed code
return CreateInternal(model);
}
private ActionResult CreateInternal(ItemRequestViewModel model)
{
if (model != null)
{
if (!String.IsNullOrEmpty(model.SiteId))
{
ViewBag.BuildingCodes = _codes.GetBuildingCodes(model.SiteId, false);
if (!String.IsNullOrEmpty(model.BuildingId))
ViewBag.LocationCodes = _codes.GetLocationCodes(model.SiteId, model.BuildingId, false);
}
//Removed code
}
//Removed code
ViewBag.WarehouseCodes = _codes.GetWarehouseCodes(false);
return View("Create", model);
}
So my questions are, how do I disable the drop down list, and how can I pass a value for the selected WarehouseId back to the view? I've also considered adding the value to the ViewBag, but to be honest I don't know enough about the ViewBag to recognize any unintended consequences I may face by just randomly modifying it's contents.
Thanks for any help offered on this.
Without going into which approach is better...
Your dropdown should be rendered as an HTML select element, in order to disable this you'll need to add a disabled="disabled" attribute to it.
The DropDownListFor method has a htmlAttributes parameter, which you can use to achieve this:
new { disabled = "disabled" }
when your pass model to your view like
return View("Create", model);
if WareHouseID is set in model then
Html.DropDownListFor(x=>x.WareHouseID, ...)
will automatically set the selected value and u don't have to do that session processing for this. So far as disabling a field is required, stewart is right. you can disable drop down this way but then it won't be posted to the server when u submit the form. you can set it to readonly mode like
new{#readonly = "readOnly"}