I have a model containing a couple of lists:
[Display(Name = "Facilities")]
public List<facility> Facilities { get; set; }
[Display(Name = "Accreditations")]
public List<accreditation> Accreditations { get; set; }
I populate these lists initially from my controller:
public ActionResult Register()
{
var viewModel = new RegisterModel();
viewModel.Facilities = m_DBModel.facilities.ToList();
viewModel.Accreditations = m_DBModel.accreditations.ToList();
return View(viewModel);
}
When they get to my view they are populated with the DB records (great). I then pass the model to the partial view which displays these lists as checkboxes, ready for user manipulation (I have tried based on another suggestion using for loop instead of foreach loop, made no difference):
#model LanguageSchoolsUK.Models.RegisterModel
#foreach (var item in Model.Facilities)
{
#Html.Label(item.name);
#Html.CheckBox(item.name, false, new { id = item.facility_id, #class = "RightSpacing", #description = item.description })
}
When I submit the form and it ends up back at my controller this time calling the overloaded register function on the controller:
[HttpPost]
public ActionResult Register(RegisterModel model)
{
if (ModelState.IsValid)
{
// Do stuff
}
return View(model);
}
The problem is that the model parameter containing the lists (Facilities and Accreditations) is telling me that the lists are null.
Please can somebody tell me what I am doing wrong, why aren't they populated with the collections that I originally passed through and hopefully a way of asking whick ones have been checked?
Thanks.
I have tried based on another suggestion using for loop instead of
foreach loop, made no difference
Try again, I am sure you will have more luck this time. Oh and use strongly typed helpers:
#model LanguageSchoolsUK.Models.RegisterModel
#for (var i = 0; i < Model.Facilities.Count; i++)
{
#Html.HiddenFor(x => x.Facilities[i].name)
#Html.LabelFor(x => x.Facilities[i].IsChecked, Model.Facilities[i].name);
#Html.CheckBoxFor(
x => x.Facilities[i].IsChecked,
new {
id = item.facility_id,
#class = "RightSpacing",
description = item.description // <!-- HUH, description attribute????
}
)
}
Also you will undoubtedly notice from my answer that checkboxes work with boolean fields on your model, not integers, not decimals, not strings => BOOLEANS.
So make sure that you have a boolean field on your model which will hold the state of the checkbox. In my example this field is called IsChecked but obviously you could feel absolutely free to find it a better name.
Related
I have read some pages regarding DDls, but I can't get my DDLF (DropDownListFor) to work. I have a model, and a db, but I don't know how I can in the view show one DDLF.
What I get to work, is this code:
#foreach (var item in Model)
{
#Html.DropDownListFor(m => item.Id,
new SelectList(ViewBag.SjukhusDropDownList),
"Choose something")
}
But then I get several DDLs. And I don't know how to insert data into them, so the data to the user will get fetched from the db. Like sending an id with something to the action, to do something with it. But here, I can only click on anything in the list, but of course, nothing will happen since I haven't bound any data to any option in that select list.
Here's an example for DropDownListFor in MVC 4
In the model create two properties, one for the list itself and one for identifying the list entries. In this example the vu-number identifies a merchant:
public class MyModel
{
[Display(Name = "VU")]
public string vu{ get; set; }
public List<SelectListItem> merchantList{ get; set; }
}
Initialize and load model data in the Http GET method of the controller:
public ActionResult ShowMerchants()
{
MyModel model = new MyModel();
model.merchantList = GetMerchants();
model.vu = model.merchantList[0].Value;
return View(model);
}
Create the list items using some rows from database. I.e. you can use TableAdapter and DataTable to achieve it:
private List<SelectListItem> GetMerchants()
{
List<SelectListItem> merchantList = new List<SelectListItem>();
MyDataSet.viewVUDataTable myDataTable = new MyDataSet.viewVUDataTable();
MyDataTableAdapters.VUListTableAdapter myTableAdapter = new MyDataTableAdapters.VUListTableAdapter();
myTableAdapter.Fill(myDataTable);
// iterate over rows in datatable
for(int i=0; i< myDataTable.Rows.Count; i++)
{
// Text is shown in the dropdownlist
// Value is used to identify the selected item
merchantList.Add(
new SelectListItem { Text = myDataTable[i].text, Value = myDataTable[i].vu});
}
return merchantList;
}
and in the view:
#Html.DropDownListFor(
model => model.vu,
Model.merchantList,
new { #class = "form-control" })
I'm working on the first MVC3 project at our company, and I've hit a block. No one can seem to figure out what's going on.
I have a complex Model that I'm using on the page:
public class SpaceModels : List<SpaceModel> {
public bool HideValidation { get; set; }
[Required(ErrorMessage=Utilities.EffectiveDate + Utilities.NotBlank)]
public DateTime EffectiveDate { get; set; }
public bool DisplayEffectiveDate { get; set; }
}
In the Controller, I create a SpaceModels object with blank SpaceModels for when Spaces get combined (this would be the destination Space).
// Need a list of the models for the View.
SpaceModels models = new SpaceModels();
models.EffectiveDate = DateTime.Now.Date;
models.DisplayEffectiveDate = true;
models.Add(new SpaceModel { StoreID = storeID, SiteID = siteID, IsActive = true });
return View("CombineSpaces", models);
Then in the View, I am using that SpaceModels object as the Model, and in the form making a TextBox for the Effective Date:
#model Data.SpaceModels
#using (Html.BeginForm("CombineSpaces", "Space")) {
<div class="EditLine">
<span class="EditLabel LongText">
New Space Open Date
</span>
#Html.TextBoxFor(m => m.EffectiveDate, new {
size = "20",
#class = "datecontrol",
// Make this as a nullable DateTime for Display purposes so we don't start the Calendar at 1/1/0000.
#Value = Utilities.ToStringOrDefault(Model.EffectiveDate == DateTime.MinValue ? null : (DateTime?)Model.EffectiveDate, "MM/dd/yyyy", string.Empty)
})
#Html.ValidationMessageFor(m => m.EffectiveDate)
</div>
<hr />
Html.RenderPartial("_SpaceEntry", Model);
}
The Partial View that gets rendered iterates through all SpaceModels, and creates a containing the Edit fields for the individual SpaceModel objects. (I'm using the List to use the same Views for when the Spaces get Subdivided as well.)
Then on the HttpPost, the EffectiveDate is still back at it's DateTime.MinValue default:
[HttpPost]
public ActionResult CombineSpaces(SpaceModels model, long siteID, long storeID, DateTime? effectiveDate) {
// processing code
}
I added that DateTime? effectiveDate parameter to prove that the value when it gets changed does in fact come back. I even tried moving the rendering of the TextBox into the _SpaceEntry Partial View, but nothing worked there either.
I did also try using the #Html.EditorFor(m => m.EffectiveDate) in place of the #Html.TextBoxFor(), but that still returned DateTime.MinValue. (My boss doesn't like giving up the control of rendering using the #Html.EditorForModel by the way.)
There has to be something simple that I'm missing. Please let me know if you need anything else.
Looking at the source code for DefaultModelBinder, specifically BindComplexModel(), if it detects a collection type it will bind the individual elements but will not attempt to bind properties of the list object itself.
What model binding does is attempt to match the names of things or elements in the view to properties in your model or parameters in your action method. You do not have to pass all of those parameters, all you have to do is add them to your view model, then call TryUpdateModel in your action method. I am not sure what you are trying to do with SpaceModel or List but I do not see the need to inherit from the List. Im sure you have a good reason for doing it. Here is how I would do it.
The view model
public class SpacesViewModel
{
public DateTime? EffectiveDate { get; set; }
public bool DisplayEffectiveDate { get; set; }
public List<SpaceModel> SpaceModels { get; set; }
}
The GET action method
[ActionName("_SpaceEntry")]
public PartialViewResult SpaceEntry()
{
var spaceModels = new List<SpaceModel>();
spaceModels.Add(
new SpaceModel { StoreID = storeID, SiteID = siteID, IsActive = true });
var spacesVm = new SpacesViewModel
{
EffectiveDate = DateTime.Now,
DisplayEffectiveDate = true,
SpaceModels = spaceModels
};
return PartialView("_SpaceEntry", spacesVm);
}
The POST action method
[HttpPost]
public ActionResult CombineSpaces()
{
var spacesVm = new SpacesViewModel();
// this forces model binding and calls ModelState.IsValid
// and returns true if the model is Valid
if (TryUpdateModel(spacesVm))
{
// process your data here
}
return RedirectToAction("Index", "Home");
}
And the view
<label>Effective date: </label>
#Html.TextBox("EffectiveDate", Model.EffectiveDate.HasValue ?
Model.EffectiveDate.Value.ToString("MM/dd/yyyy") : string.empty,
new { #class = "datecontrol" })
Sometimes you need to explicitly bind form data using hidden fields such as
#Html.HiddenField("EffectiveDate", Model.EfectiveDate.)
In order to bind the properties of the SpaceModel object you can add individual properties such as SiteID to the view model or add a SpaceModel property for a single SpaceModel. If you want to successfully bind a complex model, add it as a Dictionary populated with key-value pairs rather than a List. You should then add the dictionary to the view model. You can even add a dictionary of dictionaries for hierarchical data.
I hope this helps :)
If I were to pass additional data (other than the model) into my view, like say a list of files from a specific folder, whats the best way to do that?
I was thinking something like making a method and return a list into ViewData:
public List<string> GetFiles(int id, string cat)
{
var files = new List<string>();
var folder = "~/App_Data/uploads/" + cat + "/" + id.ToString();
foreach (var file in Directory.GetFiles(folder))
{
files.Add(file);
}
return files;
}
The controller:
ViewData["files"] = db.GetFiles(id, "random");
The view:
#foreach (var item in ViewData["files"]){ //markup }
First, ive heard that viewdata and viewbag shouldnt be used. Second, this code doesnt work. Something with Viewdata object is not enumerable. Should I make a model class for these files. If so, how? 2 models in one view? Im a bit confused how to do this proberly.
If I were to pass additional data (other than the model) into my view,
like say a list of files from a specific folder, whats the best way to
do that?
Write a view model which will contain all the properties your view needs and have your controller action pass this view model to the view. So:
public class MyViewModel
{
public List<string> Files { get; set; }
public string Foo { get; set; }
... some other properties that your view might need
}
then the controller:
public ActionResult Index(int id)
{
var model = new MyViewModel
{
Files = db.GetFiles(id, "random"),
Foo = "bar"
};
return View(model);
}
and finally in your strongly typed view:
#model MyViewModel
#foreach (var file in Model.Files)
{
<div>#file</div>
}
<div>#Html.DisplayFor(x => x.Foo)</div>
This page works in two steps,
Step 1 - The user hits Index() and the SelectList is populated with the applications from the databse.
Step 2 - they select an applicaiton from the list, which posts the page back, which reloads the page with the application Details added
Error: When I run this and get to step 2, I get an error back saying:
The ViewData item that has the key 'ApplicationId' is of type 'System.Int32' but must be of type 'IEnumerable'.
This appears to be because the Model.ApplicationList is now null as it hasn't bound back to the model when the form was posted, can I make it do this?
View:
#using (Html.BeginForm())
{
#Html.DropDownListFor(x => x.ApplicationId, Model.ApplicationList, "Select an Application" , new { #onchange = "this.form.submit();" })
}
Model:
public class IndexModel
{
public int ApplicationId { get; set; }
public List<SelectListItem> ApplicationList { get; set; }
public string Detail { get; set}
}
Controller:
public ActionResult Index()
{
using (var dc = new Entities())
{
var model = new IndexModel();
model.ApplicationList = new List<SelectListItem>();
var applications = dc.Applications.OrderBy(a => a.Name).ToList();
foreach (var application in applications)
{
model.ApplicationList.Add(new SelectListItem
{
Selected = false,
Text = application.Name,
Value = application.Id.ToString()
});
}
model.ApplicationId = 1;
return View(model);
}
}
[HttpPost]
public ActionResult Index(IndexModel model)
{
model.Detail = GetDetail(model.ApplicationId);
return View(model);
}
I was struggling with the same problem. It doesn't look like .net mvc3 lets you do this without the help of jquery. Drop down lists will get their selected item bound to the model when posting but not all the items in the combo box. You would have to rebuild it each time you pass the viewmodel back to the view.
Another way around losing the dropdown list is to use ajax.
I am using strongly typed views in an MVC3 web app. I've noticed that when a form is submitted, the ViewModel that is passed to the controller only has values for properties that have form elements associated with them. For instance, the example below shows a simple confirmation View with a checkbox and a phone number that the user must confirm before proceeding. When the form is submitted to the controller action, the UserConfirmed property contains a value, but the PhoneNumber property is null.
Is there any way for the ViewModel to retain all of its values or do I have to repopulate the ViewModel properties that do not have form elements associated with them?
The View
#model WebMeterReplacement.ViewModels.Appointment.ScheduleConfirmationViewModel
#using (Html.BeginForm()) {
#Html.ValidationSummary(false)
#Html.CheckBoxFor(model => model.UserConfirmed)
<span>Please confirm before proceeding</span>
<div>
Phone Number: #Model.PhoneNumber
</div>
<input type="submit" value="Confirm"/>
The Controller
[HttpPost]
public ActionResult ScheduleConfirmation(ScheduleConfirmationViewModel model)
{
if (model.UserConfirmed)
{
// add ViewModel data to repository
}
else
{
ModelState.AddModelError("ERROR", WebResources.strERROR_ConfirmSchedule);
}
return View(model);
}
Since your writing the phonenumber as output to the page it won't be automatically posted back (you've found out that part) What you can do is populate an hidden or read-only field with the phonenumber so that it will be posted back to your controller. An second option is to make a new call to your datasource and repopulate your object before saving it back to your datasource.
I generally POST back information like this in a hidden input. I personally use this heavily to pass data needed to return the user exactly where they where before pressing edit.
In your case it's as simple as
#model WebMeterReplacement.ViewModels.Appointment.ScheduleConfirmationViewModel
#using (Html.BeginForm()) {
#Html.ValidationSummary(false)
#Html.CheckBoxFor(model => model.UserConfirmed)
<span>Please confirm before proceeding</span>
<div>
#Html.HiddenFor(m => m.PhoneNumber)
Phone Number: #Model.PhoneNumber
</div>
<input type="submit" value="Confirm"/>
For future reference:
If your passing complex objects back you need one hidden field per attribute (Hiddenfor does NOT iterate)
View
WRONG
#Html.HiddenFor(m => m.PagingData)
RIGHT
#Html.HiddenFor(m => m.PagingData.Count)
#Html.HiddenFor(m => m.PagingData.Skip)
#Html.HiddenFor(m => m.PagingData.PageSize)
Action
public HomeController(AViewModel Model)
{
PagingData PagingData = Model.PagingData;
Skip = PagingData.Skip;
}
If your passing Arrays you can do it like this
View
#if (Model.HiddenFields != null)
{
foreach (string HiddenField in Model.HiddenFields)
{
#Html.Hidden("HiddenFields", HiddenField)
}
}
Action
public HomeController(AViewModel Model)
{
String[] HiddenFields = Model.HiddenFields;
}
Well, the form will only POST elements that you have created. As you found out, simply writing the phone number out to the page will not suffice. The model binder can only bind those properties which exist in the posted data.
Generally you have a couple of options here:
1) You can create Input elements for all of the properties in your model, using visible elements (like a textbox) for those properties you want to edit, and hidden elements which should be posted back but have no UI
2) Post back a partial representation of your model (as you are doing now), read the entity back in from it's data source (I assume you're using some kind of data source, EF maybe) and then alter the properties of that entity with the ones from your form.
Both scenarios are common but it really depends on the complexity of your model.
I know this thread is a bit old, but thought I'd resurrect it to get feed back on my solution to this.
I'm in a similar situation where my objects are passed to a view, and the view may only display part of that object for editing. Obviously, when the controller receives the model back from the default model binder, and values not posted back become null.. and saving this means that a DB value becomes null just because it wasn't displayed/returned from a view.
I didn't like the idea of creating a model for each view. I know it's probably the right way... but I was looking for a reusable pattern that can be implemented fairly quickly.
See the "MergeWith" method... as this would be used to take a copy of the object from the database and merge it with the one returned from the view (posted back)
namespace SIP.Models
{
[Table("agents")]
public class Agent
{
[Key]
public int id { get; set; }
[Searchable]
[DisplayName("Name")]
[Column("name")]
[Required]
[StringLength(50, MinimumLength = 4)]
public string AgentName { get; set; }
[Searchable]
[DisplayName("Address")]
[Column("address")]
[DataType(DataType.MultilineText)]
public string Address { get; set; }
[DisplayName("Region")]
[Searchable]
[Column("region")]
[StringLength(50, MinimumLength = 3)]
public string Region { get; set; }
[DisplayName("Phone")]
[Column("phone")]
[StringLength(50, MinimumLength = 4)]
public string Phone { get; set; }
[DisplayName("Fax")]
[Column("fax")]
[StringLength(50, MinimumLength = 4)]
public string Fax { get; set; }
[DisplayName("Email")]
[RegularExpression(#"(\S)+", ErrorMessage = "White space is not allowed")]
[Column("email")]
[StringLength(50, MinimumLength = 4)]
public string Email { get; set; }
[DisplayName("Notes")]
[Column("notes")]
[DataType(DataType.MultilineText)]
public string Notes{ get; set; }
[DisplayName("Active")]
[Column("active")]
public bool Active { get; set; }
public override string ToString()
{
return AgentName;
}
public bool MergeWith(Agent a, string[] fields)
{
try
{
foreach (PropertyInfo pi in this.GetType().GetProperties())
{
foreach (string f in fields)
{
if (pi.Name == f && pi.Name.ToLower() != "id")
{
var newVal = a.GetType().GetProperty(f).GetValue(a,null);
pi.SetValue(this, newVal, null);
}
}
}
}
catch (Exception ex)
{
return false;
//todo: Log output to file...
}
return true;
}
}
}
And to use this in the controller.. you'd have something like..
[HttpPost]
public ActionResult Edit(Agent agent)
{
if (ModelState.IsValid)
{
Agent ag = db.Agents.Where(a => a.id == agent.id).ToList<Agent>().First<Agent>();
ag.MergeWith(agent, Request.Params.AllKeys);
db.Entry(ag).State = EntityState.Modified;
db.SaveChanges();
return RedirectToAction("Index");
}
return View(agent);
}
This way, during post back, it takes the object from the database, and updates it with object from view... but only updates the values that were posted back.. So if you have a field like "address" or something that doesn't appear in the view.. it doesn't get touched during the update.
I've tested this so far and i works for my purposes, tho i welcome any feedback as I'm keen to see how others have overcome this situation. It's a first version and i'm sure it can be implemented better like through an extension method or something.. but for now the MergeWith can be copy/pasted to each model object.
Yes, Just place hidden fields in the form for those values which you are not using and want to return to server control.
Thanks