Im trying to use IEnumerable so it holds multiple selections so a user can choose more then one value in my listbox.
This is how my ViewModel looks like:
public class CreateViewModel
{
public IEnumerable<string> SelectedValues { get; set; }
public IEnumerable<CoreValue> CoreValues { get; set; }
}
This is my GET in my controller:
public ActionResult Create()
{
CreateViewModel model = new CreateViewModel();
model.CoreValues = AdminRepository.GetAllCoreValues();
return View(model);
}
This how my view looks like:
#Html.ListBoxFor(m => m.SelectedValues, new MultiSelectList(Model.CoreValues, "Id", "Name"))
How do I code my POST action so that SelectedValues will be used to contain the selected values on the post?
Before Ienumerable I had string declared to CoreValueName in my ViewModel and I did something like this in my POST action which worked perfectly but now I changed it to Ienumerable and I have am not sure how to code so my selectedvalues will be used to contain the selected values in my post.
Question question = new Question();
var CoreValueID = int.parse(model.CoreValueName);
var GetAllCoreValuesID = AdminRep.GetByCoreValueID(CoreValueID);
question.CoreValue.Add(GetAllCoreValuesID);
AdminRepository.AddQuestion(question);
AdminRepository.save();
This version of my POST action works perfectly beacuse model.SubjectType is declared as string in my Viewmodel:
[HttpPost]
public ActionResult Create(AdminCreateViewModel model)
{
Question question = new Question();
var SubjectTypeID = int.Parse(model.SubjecTypeName);
var GetAllSubjecTypesID = AdminRep.GetBySubjectTypeID(SubjectTypeID);
question.SubjectType.Add(GetAllSubjecTypesID);
AdminRep.AddQuestion(question);
AdminRep.save();
}
This version of my Post action is not working beacuse Model.Selectedvalues is declared as Ienumerable string in my ViewModel. I tried to int.parse my model.SelectedValues but that doesnt work with Ienumerable. And GetByCoreValueID method takes int as argument so I have no idea how do to this. Do I need foreach?
[HttpPost]
public ActionResult Create(AdminCreateViewModel model)
{
Question question = new Question();
var CoreValueID = model.SelectedValues;
var GetAllCoreValuesID = AdminRep.GetByCoreValueID(CoreValueID); //
question.CoreValue.Add(GetAllCoreValuesID);
AdminRep.AddQuestion(question);
AdminRep.save();
Thanks in advance!
You could have your POST controller action take the view model as argument. Then the SelectedValues property will contain a list of values that the user selected:
[HttpPost]
public ActionResult Index(CreateViewModel model)
{
model.SelectedValues will cnotain the selected values from the user here
...
}
Related
My scenario is much complicated so i simplified it with the example below. The main problem is binding collection properties of a model, specifying the path of the property like Html.TextBox("List[0].Name") and not the Html.TextBoxFor(t => t.List[0].Name). So, for the current view i will only know some of the metadata of the model so i will have to construct it this way. Here is the scenario :
Model
public class ModelTest
{
public int Id {get;set;}
public List<Foo> Collection {get;set;}
}
public class Foo
{
public string Value1 {get;set;}
public string Value2 {get;set;}
}
Controller
public class TestController: Controller
{
[HttpGet]
public ActionResult Test()
{
var model = new ModelTest()
{
Id = 455,
Collection = new List<Foo>()
{
new Foo(){ Value1 = "sagasga", Value2 = "Beul"},
new Foo(){ Value1 = "dgdsgds", Value2 = "fhfhd" }
}
};
return View(model);
}
[HttpPost]
public ActionResult Test( ModelTest model)
{
//....
return View();
}
View:
#using (Html.BeginForm())
{
#Html.TextBox("Id")
#Html.TextBox("Collection[0].Value1")
#Html.TextBox("Collection[0].Value2")
<input type="submit" value="Add" />
}
For the code above i get empty textboxes for the collection values. However, when the page is submited i get the model built correct in the Post method.
Many thanks,
Alex
This is the way to name you input fields when you wanna post a collection to your controller. However, you have to specify the initial value yourself. Your code is currently just creating textbox with the name property set to Collection[0].Value1. You still need to specify the input this way,
#Html.TextBox("Collection[0].Value1", Model.Collection.FirstOrDefault().Value1)
#Html.TextBox("Collection[0].Value2", Model.Collection.FirstOrDefault().Value2)
ASP.Net MVC 4
I am trying to populate a list of Countries (data from Country table in DB) in a dropdownlist. I get the following error:
The model item passed into the dictionary is of type
System.Collections.Generic.List`1[System.Int32]', but this dictionary requires a model item of type 'BIReport.Models.Country'.
I am new to ASP.Net MVC and I don't understand that error. What I feel is what Index method is returning doesn't match with the model that I am using in the View.
Model::
namespace BIReport.Models
{
public partial class Country
{
public int Country_ID { get; set; }
public string Country_Name { get; set; }
public string Country_Code { get; set; }
public string Country_Acronym { get; set; }
}
}
Controller::
public class HomeController : Controller
{
private CorpCostEntities _context;
public HomeController()
{
_context = new CorpCostEntities();
}
//
// GET: /Home/
public ActionResult Index()
{
var countries = _context.Countries.Select(arg => arg.Country_ID).ToList();
ViewData["Country_ID"] = new SelectList(countries);
return View(countries);
}
}
View::
#model BIReport.Models.Country
<label>
Country #Html.DropDownListFor(model => model.Country_ID, ViewData["Country_ID"] as SelectList)
</label>
Where am I going wrong?
You are selecting CountryIDs, therefore you will have a list of integers passed into the view.
I think you really want something like this:
public ActionResult Index()
{
var countries = _context.Countries.ToList();
ViewData["Country_ID"] = new SelectList(countries, "Country_ID", "Country_Name");
return View();
}
I'm not really sure why you have single country as a model for your view.
Update:
I'm still not sure why the model is a country, if you are just going to post the ID of the selected country you don't necessarily need a model at all (or just have an integer). This will be just fine though:
View
#model MvcApplication1.Models.Country
#Html.DropDownListFor(m => m.Country_ID, ViewData["Country_ID"] as SelectList)
the problem is in line 1 of your view. change it like this :
#model IEnumerable<BIReport.Models.Country>
also there is no need to pass the model to view if you already did it by :
ViewData["Country_ID"] = new SelectList(countries);
When you say #model BIReport.Models.Country it means your view is expecting a model consisting single country details. On the contrary you need a list of countries to be displayed in the drop-down list. Hence you should tell the view to look for a list of country details instead.
Therefore #model IEnumerable.
I'm attempting to create a single Controller class to handle all foreseeable surveys that I'll end up creating in the future. Currently I have a 'Surveys' table with fields: Id, SurveyName, Active. On the 'master' Surveys' Index page I list out every SurveyName found in that table. Each SurveyName is clickable, and when clicked on, the page sends the SurveyName as a string to the receiving controller action. Said controller action looks like this:
//
//GET: /Surveys/TakeSurvey/
public ActionResult TakeSurvey(string surveyName)
{
Assembly thisAssembly = Assembly.GetExecutingAssembly();
Type typeToCreate = thisAssembly.GetTypes().Where(t => t.Name == surveyName).First();
object newSurvey = Activator.CreateInstance(typeToCreate);
ViewBag.surveyName = surveyName;
return View(surveyName, newSurvey);
}
Using reflection I am able to create a new instance of the type (Model) designated by the passed-in string 'surveyName' and am able to pass that Model off to a view with the same name.
EXAMPLE
Someone clicks on "SummerPicnic," the string "SummerPicnic" is passed to the controller. The controller, using reflection, creates a new instance of the SummerPicnic class and passes it to a view with the same name. A person is then able to fill out a form for their summer picnic plans.
This works all fine and dandy. The part that I'm stuck at is trying to save the form passed back by the POST method into the correct corresponding DB table. Since I don't know ahead of time what sort of Model the controller will be getting back, I not only don't know how to tell it what sort of Model to save, but where to save it to, either, since I can't do something ridiculous like:
//
//POST: Surveys/TakeSurvey
[HttpPost]
public ActionResult TakeSurvey(Model survey)
{
if (ModelState.IsValid)
{
_db. + typeof(survey) + .Add(survey);
_db.SaveChanges();
return RedirectToAction("Index", "Home");
}
return View();
}
Is there a way to do this, or should I go about this from a whole different angle? My ultimate goal is to have a single Controller orchestrating every simple-survey, so I don't have to create a separate controller for every single survey I end up making down the road.
An alternative solution I can think of is to have a separate method for every survey, and to have which method to call defined inside of every survey's view. For example, if I had a SummerPicnic survey, the submit button would call an ActionMethod called 'SummerPicnic':
#Ajax.ActionLink("Create", "SummerPicnic", "Surveys", new AjaxOptions { HttpMethod = "POST" })
A survey for PartyAttendance would call an ActionMethod 'PartyAttendance,' etc. I'd rather not have to do that, though...
UPDATE 1
When I call:
_db.Articles.Add(article);
_db.SaveChanges();
This is what _db is:
private IntranetDb _db = new IntranetDb();
Which is...
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;
using System.Data.Entity.ModelConfiguration.Conventions;
namespace Intranet.Models
{
public class IntranetDb : DbContext
{
public DbSet<Article> Articles { get; set; }
public DbSet<ScrollingNews> ScrollingNews { get; set; }
public DbSet<Survey> Surveys { get; set; }
public DbSet<Surveys.test> tests { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
}
}
}
You can try something like this,
UPDATE:
The built-in UpdateModel will work with generic model see this post, so we got little more work.
[HttpPost]
public ActionResult TakeSurvey(FormCollection form, surveyName)
{
var surveyType = Type.GetType(surveyName);
var surveyObj = Activator.CreateInstance(surveyType);
var binder = Binders.GetBinder(surveyType);
var bindingContext = new ModelBindingContext()
{
ModelMetadata = ModelMetadataProviders.Current.GetMetadataForType(() => surveyObj, surveyType),
ModelState = ModelState,
ValueProvider = form
};
binder.BindModel(ControllerContext, bindingContext);
if (ModelState.IsValid)
{
// if "db" derives from ObjectContext then..
db.AddObject(surveyType, surveyObj);
db.SaveChanges();
// if "db" derives from DbContext then..
var objCtx = ((IObjectContextAdapter)db).ObjectContext;
objCtx.AddObject(surveyType, surveyObj);
db.SaveChanges();
return RedirectToAction("Index", "Home");
}
return View();
}
Check this two know the diff between DbContext and ObjectContext
I ended up with a slightly modified version of Mark's code:
[HttpPost]
public ActionResult TakeSurvey(string surveyName, FormCollection form)
{
//var surveyType = Type.GetType(surveyName);
//var surveyObj = Activator.CreateInstance(surveyType);
// Get survey type and create new instance of it
var thisAssembly = Assembly.GetExecutingAssembly();
var surveyType = thisAssembly.GetTypes().Where(t => t.Name == surveyName).First();
var newSurvey = Activator.CreateInstance(surveyType);
var binder = Binders.GetBinder(surveyType);
var bindingContext = new ModelBindingContext()
{
ModelMetadata = ModelMetadataProviders.Current.GetMetadataForType(() => newSurvey, surveyType),
ModelState = ModelState,
ValueProvider = form
};
binder.BindModel(ControllerContext, bindingContext);
if (ModelState.IsValid)
{
var objCtx = ((IObjectContextAdapter)_db).ObjectContext;
objCtx.AddObject(surveyName, newSurvey);
_db.SaveChanges();
return RedirectToAction("Index", "Home");
}
return View();
}
I was running into surveyType being 'null' when it was set to Type.GetType(surveyName); so I went ahead and retrieved the Type via Reflection.
The only trouble I'm running into now is here:
if (ModelState.IsValid)
{
var objCtx = ((IObjectContextAdapter)_db).ObjectContext;
objCtx.AddObject(surveyName, newSurvey);
_db.SaveChanges();
return RedirectToAction("Index", "Home");
}
When it tries to AddObject I'm getting the exception "The EntitySet name 'IntranetDb.test' could not be found." I just need to figure out to strip off the prefix 'IntranetDb.' and hopefully I'll be in business.
UPDATE
One thing I completely overlooked was passing the Model to the controller from the View...oh bother. I currently have an ActionLink replacing the normal 'Submit' button, as I wasn't sure how else to pass to the controller the string it needs to create the correct instance of Survey model:
<p>
#Ajax.ActionLink("Create", "TakeSurvey", "Surveys", new { surveyName = ViewBag.surveyName }, new AjaxOptions { HttpMethod = "POST" })
#*<input type="submit" value="Create" />*#
</p>
So once I figure out how to turn 'IntranetDb.test' to just 'test' I'll tackle how to make the Survey fields not all 'null' on submission.
UPDATE 2
I changed my submission method from using an Ajax ActionLink to a normal submit button. This fixed null values being set for my Model values after I realized that Mark's bindingContext was doing the binding for me (injecting form values onto the Model values). So now my View submits with a simple:
<input type="submit" value="Submit" />
Back to figuring out how to truncate 'IntranetDb.test' to just 'test'...
Got It
The problem lies in my IntranetDb class:
public class IntranetDb : DbContext
{
public DbSet<Article> Articles { get; set; }
public DbSet<ScrollingNews> ScrollingNews { get; set; }
public DbSet<SurveyMaster> SurveyMaster { get; set; }
public DbSet<Surveys.test> tests { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
}
}
objCtx.AddObject(surveyName, newSurveyEntry); was looking for an entry (an "EntitySet") in the IntranetDb class called "test." The problem lies in the fact that I don't have an EntitySet by the name of "test" but rather by the name of "tests" with an 's' for pluralization. Turns out I don't need to truncate anything at all, I just need to point to the right object :P Once I get that straight I should be in business! Thank you Mark and Abhijit for your assistance! ^_^
FINISHED
//
//POST: Surveys/TakeSurvey
[HttpPost]
public ActionResult TakeSurvey(string surveyName, FormCollection form)
{
//var surveyType = Type.GetType(surveyName);
//var surveyObj = Activator.CreateInstance(surveyType);
// Create Survey Type using Reflection
var thisAssembly = Assembly.GetExecutingAssembly();
var surveyType = thisAssembly.GetTypes().Where(t => t.Name == surveyName).First();
var newSurveyEntry = Activator.CreateInstance(surveyType);
// Set up binder
var binder = Binders.GetBinder(surveyType);
var bindingContext = new ModelBindingContext()
{
ModelMetadata = ModelMetadataProviders.Current.GetMetadataForType(() => newSurveyEntry, surveyType),
ModelState = ModelState,
ValueProvider = form // Get values from form
};
var objCtx = ((IObjectContextAdapter)_db).ObjectContext;
// Retrieve EntitySet name for Survey type
var container = objCtx.MetadataWorkspace.GetEntityContainer(objCtx.DefaultContainerName, DataSpace.CSpace);
string setName = (from meta in container.BaseEntitySets
where meta.ElementType.Name == surveyName
select meta.Name).First();
binder.BindModel(ControllerContext, bindingContext); // bind form values to survey object
if (ModelState.IsValid)
{
objCtx.AddObject(setName, newSurveyEntry); // Add survey entry to appropriate EntitySet
_db.SaveChanges();
return RedirectToAction("Index", "Home");
}
return View();
}
It's kind of bloated but it works for now. This post helped me get the EntitySet from the Survey object itself so I didn't need to worry about establishing some sort of EntitySet naming convention.
The main problem I see is to bind to the model to the TakeSurvey POST method. If you want different types of survey models should be handled by this method and MVC should bind to this model before calling the action, I believe you can have a wrapper model class over all such generic model, say SurveyModel and use custom model binder to bind to these models.
public class SurveyModel
{
public string GetSurveyModelType();
public SummerPicnicSurvey SummerPicnicSurvey { get; set; }
public PartyAttendanceSurvey PartyAttendanceSurvey { get; set; }
}
Then write a custom mobel binder to bind this model. From the request form fields we can see what type of survey model is posted and then accordingly fetch all the fields and initialize the SurveyModel class. If SummerPicnicSurvey is posted then class SurveyModel will be set with this class and PartyAttendanceSurvey will be null. Example custom model binder.
From the controller action TakeSurvey POST method, You can update db like this:
[HttpPost]
public ActionResult TakeSurvey(SurveyModel survey)
{
if (ModelState.IsValid)
{
if(survey.GetSurveyModelType() == "SummerPicnicSurvey")
_db.UpdateSummerPicnicSurvey(survey.SummerPicnicSurvey);
else if (survey.GetSurveyModelType() == "PartyAttendanceSurvey")
_db.UpdateSummerPicnicSurvey(survey.PartyAttendanceSurvey);
_db.SaveChanges();
return RedirectToAction("Index", "Home");
}
return View();
}
Instead of SurveyModel encapsulating the other surveys you can have inheritance and use .net as to typecast with a check and use the Model.
Having said this, I think there is no harm in using different methods for each model. This will enable you to unit test the code well. Too many if else is not healthy to maintain. Or you can transfer the generic model SurveyModel to the repository or data access layer and let it handle that in a polymorphic way. I would prefer more small functions and keep the code clean.
Edit: The inheritance way:
public class SurveyModel
{
public virtual bool Save();
}
public partial class SummerPicnicSurvey : SurveyModel
{
public bool Save(SummerPicnicSurvey survey)
{
using(var _dbContext = new MyContext())
{
_dbContex.SummerPicnicSurveys.Add(survey);
_dbContex.SaveChanges();
}
}
}
[HttpPost]
public ActionResult TakeSurvey(SurveyModel survey)
{
if (ModelState.IsValid)
{
survey.Save();
return RedirectToAction("Index", "Home");
}
return View();
}
Any new Survey model type you add has to implement the SaveChanges or Save method, Which would call the proper dbcontext method. The controller action would just call Save on the generic `SurveyModel' reference passed to it. Thus the action will be closed for modification but open for modification. The open-close design principle.
I've read many articles which they state that querying should not be placed in the Controller, but I can't seem to see where else I would place it.
My Current Code:
public class AddUserViewModel
{
public UserRoleType UserRoleType { get; set; }
public IEnumerable<SelectListItem> UserRoleTypes { get; set; }
}
public ActionResult AddUser()
{
AddUserViewModel model = new AddUserViewModel()
{
UserRoleTypes = db.UserRoleTypes.Select(userRoleType => new SelectListItem
{
Value = SqlFunctions.StringConvert((double)userRoleType.UserRoleTypeID).Trim(),
Text = userRoleType.UserRoleTypeName
})
};
return View(model);
}
The View:
<li>#Html.Label("User Role")#Html.DropDownListFor(x => Model.UserRoleType.UserRoleTypeID, Model.UserRoleTypes)</li>
How do I retain the View Model and Query and exclude the User Type that should not show up?
I think that you are doing it just fine.
Any way... all you can do to remove the querying logic from controller is having a ServiceLayer where you do the query and return the result.
The MVC pattern here is used correctly... what your are lacking is the other 2 layers (BusinessLayer and DataAccessLayer)... since ASP.NET MVC is the UI Layer.
UPDATE, due to comment:
Using var userroletypes = db.UserRoleTypes.Where(u=> u.UserRoleType != 1);
is OK, it will return a list of UserRoleType that satisfy the query.
Then, just create a new SelectList object using the userroletypes collection... and asign it to the corresponding viewmodel property. Then pass that ViewModel to the View.
BTW, I never used the db.XXXX.Select() method before, not really sure what it does... I always use Where clause.
SECOND UPDATE:
A DropDownList is loaded from a SelectList that is a collection of SelectItems.
So you need to convert the collection resulting of your query to a SelectList object.
var userroletypes = new SelectList(db.UserRoleTypes.Where(u=> u.UserRoleType != 1), "idRoleType", "Name");
then you create your ViewModel
var addUserVM = new AddUserViewModel();
addUserVM.UserRoleTypes = userroletypes;
and pass addUserVM to your view:
return View(addUserVM );
Note: I'm assuming your ViewModel has a property of type SelectList... but yours is public IEnumerable<SelectListItem> UserRoleTypes { get; set; } so you could change it or adapt my answer.
I don't see anything wrong with your code other than this db instance that I suppose is some concrete EF context that you have hardcoded in the controller making it impossible to unit test in isolation. Your controller action does exactly what a common GET controller action does:
query the DAL to fetch a domain model
map the domain model to a view model
pass the view model to the view
A further improvement would be to get rid of the UserRoleType domain model type from your view model making it a real view model:
public class AddUserViewModel
{
[DisplayName("User Role")]
public string UserRoleTypeId { get; set; }
public IEnumerable<SelectListItem> UserRoleTypes { get; set; }
}
and then:
public ActionResult AddUser()
{
var model = new AddUserViewModel()
{
UserRoleTypes = db.UserRoleTypes.Select(userRoleType => new SelectListItem
{
Value = SqlFunctions.StringConvert((double)userRoleType.UserRoleTypeID).Trim(),
Text = userRoleType.UserRoleTypeName
})
};
return View(model);
}
and in the view:
#model AddUserViewModel
<li>
#Html.LabelFor(x => x.UserRoleTypeId)
#Html.DropDownListFor(x => x.UserRoleTypeId, Model.UserRoleTypes)
</li>
I using MVC-Viewmodel in my project, my problem is that even if i CTRL-click two values in my listbox It only grabs one value. I want users to be able to select two values but I dont know why it doesnt happen any tips is appreciated!
Here is my GET n POST action inside my controller:
public ActionResult Create()
{
CreateViewModel model = new CreateViewModel();
List<CoreValue> corevalues = Arep.getallC();
model.CoreValuess = new MultiSelectList(corevalues, "CID", "Cname");
return View(model);
}
[HttpPost]
public ActionResult Create(CreateViewModel model)
{
if (ModelState.IsValid)
{
Question q = new Question();
var CoreValueID = int.Parse(model.Cname);
var getallC = Arep.getbycid(CoreValueID);
q.CoreValue.Add(getallC);
q.QuestionText = model.QuestionText;
Arep.addquestion(q);
Arep.save();
return RedirectToAction("Index");
}
return View(model);
This is inside my CreateViewModel:
public MultiSelectList CoreValues { get; set; }
And this is inside my View:
#Html.ListBoxFor(model => model.Cname,Model.Corevaluess)
What seem to be the problem?
Thanks in Advance!
Best Regards
Spelling errors aside, I believe the following is why this is failing:
In your ListBoxFor method, you are using model.Cname. By this, I believe you mean "choose the cName of selected CoreValues". However (and I'm guessing because I can't see your model), the Cname property on the CreateViewModel is of type string. Because of this, you are only ever going to have one value at a time. You need a property that is of type IEnumerable in order to hold multiple selections.
Update your model to the following:
public class CreateViewModel
{
public IEnumerable<string> SelectedValues { get; set; }
public IEnumerable<CoreValue> CoreValues { get; set; }
}
SelectedValues will be used to contain the selected values on the post. We can also add items to it to signify what should be automatically selected when the view is created.
In your controller do the following:
public ActionResult Create()
{
CreateViewModel model = new CreateViewModel();
model.CoreValues = Arep.getallC();
return View(model);
}
Lastly, update the view:
#Html.ListBoxFor(m => m.SelectedValues, new MultiSelectList(Model.CoreValues, "CID", "Cname"))
Now, whenever you post, you should be able to see the values that a user selected.
EDIT: I'm not completely sure what some of your methods do so I'm taking a guess.
The POST method for Create:
[HttpPost]
public ActionResult Create(CreateViewModel model)
{
if (ModelState.IsValid)
{
foreach(var CoreValueID in model.SelectedValues)
{
Question q = new Question();
var getallC = Arep.getbycid(CoreValueID);
q.CoreValue.Add(getallC);
q.QuestionText = model.QuestionText;
Arep.addquestion(q);
}
Arep.save();
return RedirectToAction("Index");
}
return View(model);
}
you would need to pass selectedvalues as below
List<CoreValue> selectedvalues = Null;
model.CoreValuess = new MultiSelectList(corevalues, "CID", "Cname",selectedvalues);
return View(model);
Refer MSDN link and this helpful Article
As stated above, the ASP.Net Mvc wants to have a list of string, but the same thing can be achieved by using the classic ASP style
Request.Form["CoreValues"]
this will provide as comma separated values.