mvc passing data between controller and view - asp.net-mvc

I am developing an application. I have created a view and a controller. The view has a button, on the click of which I am supposed to do database operations. I have put the database operations in the model, I am creating the object of model in the controller. On clicking the button the action is handled by a method in the controller, and the object of the model is created to get the records from the database. I would like to know if there is any way to display this data in the view.Is the approach correct or the view is supposed to interact with model directly to get the data.
Following is the code in controller that gets invoked on the button click
public ActionResult getRecord()
{
DataModel f_DM = new DataModel();
DataTable f_DT = f_DM.getRecord();
return View();
}
DataModel is the model class with simply a method "getRecord".
Any help will be highly appreciated.
I would like to add that i am using vs2010 and mvc4
Regards

you should write the logic of retrieving data in your controller. Store all your data in view model and pass it to the view.
for eg.
Model
namespace Mvc4App.Models
{
public class Product
{
public string Name { get; set; }
}
public class ProductViewModel
{
public Product Product { get; set; }
public string SalesPerson { get; set; }
}
}
Controller
public class ProductController : Controller
{
public ActionResult Info()
{
ProductViewModel ProductViewModel = new ProductViewModel
{
Product = new Product { Name = "Toy" },
SalesPerson = "Homer Simpson"
};
return View(ProductViewModel);
}
}
View
#model Mvc4App.Models.ProductViewModel
#{ ViewBag.Title = "Info"; }
<h2>Product: #Model.Product.Name</h2>
<p>Sold by: #Model.SalesPerson</p>
This is the best known practice to pass data from controller to the view.
you may use other techniques also like,
1. ViewData
2. ViewBag
3. TempData
4. View Model Object
5. Strongly-typed View Model Object

Yes, it's possible, but actually now very logical way to to this.
Lets follow your way. You have some View were you have a button, that will trigger this action.
For ex:
public ActionResult Index()
{
return View();
}
Inside view you can have a Ajax link, that will trigget your getRecord method:
<div id="GetDataDiv"></div>
<div>
#Ajax.ActionLink("Get Record", "getRecord", "ControllerName", null, new AjaxOptions() { HttpMethod = "GET", UpdateTargetId = "GetDataDiv" })
</div>
In the getRecord method you should have:
public ActionResult getRecord()
{
DataModel f_DM = new DataModel();
DataTable f_DT = f_DM.getRecord();
return PartialView(f_DT);
}
And in View it should be:
#model DataTable
#Model.PropertyOne #Model.PropertyTwo
It should works for you.
Actually same exaple here: http://www.dotnetpools.com/Article/ArticleDetiail/?articleId=151

Related

Correct way to display a list in a dropdown using mvc

I know there are a lot of similar question here but none seem quite the same as mine.
In my View:
#model LocalInformedMotionServer.Models.FeedData
#Html.DropDownList("Premise", Model.LoadUp("key"), new { #style = "width: 218px;height:35px;" })
In my controller:
public class CloudController : Controller
{
public IEnumerable<wsCommon.Premise> Premises { get; set; }
public ActionResult Feed(string key)
{
var feedData = new FeedData();
Premises= feedData.LoadUp(key);
return View(feedData);
}
}
In my Model:
public class FeedData
{
public IEnumerable<wsCommon.Premise> LoadUp(string saltKey)
{
Premises premises = new InformedBiz.Premises();
return premises.GetPremises(saltKey);
}
}
It errors because the variable:
"key"
in this call:
Model.LoadUp("key")
is being read in as'null' in my controller method.
Of course as this is all new to me I could be doing this all wrong..
ADDITIONAL:
In my CloudController Class I have this:
public class CloudController : Controller
{
public ActionResult Feed(string saltKey)
{
var feedData = new FeedData();
feedData.LoadUp(saltKey);
return View(feedData);
}
public ActionResult Index()
{
return View();
}
public ActionResult LogIn()
{
return View();
}
}
I'm not sure what your Premise class looks like, but I usually use an IEnumberable of SelectListItem for drop downs in my views. So you could do something like this:
public IEnumerable<SelectListItem> LoadUp(string saltKey)
{
Premises premises = new InformedBiz.Premises();
return premises.GetPremises(saltKey).Select(
p => new SelectListItem { Text = p.Name, Value = z.PremiseId.ToString() }
);
}
You'll also need to create a Post ActionResult method that accepts the model in your view (FeedData) as well as wrap your DropDownList control in a Html.BeginForm, to post results to the controller. Hope this makes a bit of sense.
You have not posted the properties of your FeedData model but assuming it contains a property which is typeof Premise and you want to be able to select a Premise from a collection, then using a view model that represents what you want to display/edit is the recommended approach (refer View Model Design And Use In Razor Views and What is ViewModel in MVC?)
You view model might look like
public class FeedDataVM
{
.....
[Display(Name = "Premise")]
[Required(ErrorMessage = "Please select a Premise")]
public int? SelectedPremise { get; set; }
....
public SelectList PremiseList { get; set; }
}
and in your controller (not sure what saltKey is for?)
public ActionResult Feed(string saltKey)
{
FeedDataVM model = new FeedDataVM();
IEnumerable<Premise> premises = // get the collection of premise objects from your repository
// assuming you want to display the name property of premise, but post back the key property
model.PremiseList = new SelectList(premises, "key", "name");
return View(model);
}
View
#model FeedDataVM
#using(Html.BeginForm())
{
....
#Html.LabelFor(m => m.SelectedPremise)
#Html.DropDownListFor(m => m.SelectedPremise, Model.PremiseList, "-Please select")
#Html.ValidationMessageFor(m => m.SelectedPremise)
....
<input type="submit" value="Save" />
}
and the POST method
public ActionResult Feed(FeedDataVM model)
{
// model.SelectedPremise contains the value of the selected option as defined by the key property of Premise
}
Side note: Your FeedData model contains a method to retrieve a collection of Premise which appears to be calling another service. You should avoid this type of design which makes it difficult to debug and unit test. Your controller is responsible for initializing/getting you data models and view models and for populating/mapping their properties.

Asp.Net MVC 5 How to send ViewBag to Partial View

I have a _LoginPartial View and want to send data to it by ViewBag, but the Controller that I'am sending data from, doesn't have a View.
public PartialViewResult Index()
{
ViewBag.sth = // some data
return PartialView("~/Views/Shared/_LoginPartial.cshtml");
}
This code didn't work for me.
It seems you're expecting this Index action to be called when you do: #Html.Partial('_LoginPartial'). That will never happen. Partial just runs the partial view through Razor with the current view's context and spits out the generated HTML.
If you need additional information for your partial, you can specify a custom ViewDataDictionary:
#Html.Partial("_LoginPartial", new ViewDataDictionary { Foo = "Bar" });
Which you can then access inside the partial via:
ViewData["Foo"]
You can also use child actions, which is generally preferable if working with a partial view that doesn't need the context of the main view. _LoginPartial seems like a good candidate, although I'm not sure how exactly you're using it. Ironically, though, the _LoginPartial view that comes with a default MVC project with individual auth uses child actions.
Basically, the code you have would already work, you would just need to change how you reference it by using Html.Action instead of Html.Partial:
#Html.Action("Index")
Notice that you're calling the action here and now the view.
You can always pass data directly to the partial view.
public PartialViewResult Index()
{
var data = // some data
return PartialView("~/Views/Shared/_LoginPartial.cshtml", data);
}
Pass multiple pieces of data
public class MyModel
{
public int Prop1 { get; set; }
public int Prop2 { get; set; }
}
public PartialViewResult Index()
{
var data = new MyModel(){ Prop1 = 5, Prop2 = 10 };
return PartialView("~/Views/Shared/_LoginPartial.cshtml", data);
}
I passed viewBag data to my partial view like below, and I converted that viewBag data object to JSON in my partial view by using #Html.Raw(Json.Encode(ViewBag.Part));
my code sample is given below.
public async Task<ActionResult> GetJobCreationPartialView(int id)
{
try
{
var client = new ApiClient<ServiceRepairInspectionViewModel>("ServiceRepairInspection/GetById");
var resultdata = await client.Find(id);
var client2 = new ApiClient<PartViewModel>("Part/GetActive");
var partData = await client2.FindAll();
var list = partData as List<PartViewModel> ?? partData.ToList();
ViewBag.Part = list.Select(x => new SelectListItem() {Text = x.PartName, Value = x.Id.ToString()});
return PartialView("_CreateJobCardView" ,resultdata);
}
catch (Exception)
{
throw;
}
}
Here i have passed both model and viewBag .
First off, the code in your question does not run. When you do #Html.Partial("_SomeView") the Index() method you have there does not run. All #Html.Partial("_SomeView") does is render _SomeView.cshtml in your current view using the current view's ViewContext.
In order to get this to work you need a bit of functionality that's common to all the controllers in your project. You have two options: extension method for ControllerBase or a BaseController that all the controllers in your project inherit from.
Extension method:
Helper:
public static class ControllerExtensions
{
public static string GetCommonStuff(this ControllerBase ctrl)
{
// do stuff you need here
}
}
View:
#ViewContext.Controller.GetCommonStuff()
BaseController
Controller:
public class BaseController : Controller
{
public string GetCommonStuff()
{
// do stuff you need here
}
}
Other controllers:
public class SomeController : BaseController
...
...
View:
#((ViewContext.Controller as BaseController).GetCommonStuff())

How to provide a model to a nested view in MVC (Razor)

Suppose I'm rendering another page(view) to a page (view).
Now the nested view has its separate model. How to provide the model to the nested view.
Here is the example.
my Index Controller:
public ActionResult Index()
{
ViewBag.CreateModel = new Todo();
return View(db.Todos.ToList());
}
my Index View:
IEnumerable<ToDoMVC.Models.Todo>
#RenderPage("~/Views/Todo/Create.cshtml",ViewBag.CreateModel)
my Create View:
#model ToDoMVC.Models.Todo
// does operations with this model
Now, if I run the program it gives me some model type mismatch error for create view.
So, how to solve this? How to provide another model to a nested view from a view?
In your model you would have a seperate model as a variable.
For example
class Todo {
public CreateModel create {get;set}
}
Then when you pass through to the second view you would do something like this:
#RenderPage("~/Views/Todo/Create.cshtml",Model.create)
That will pass that second model to your create page
Edit
Re-reading your question.
The mismatch will be because you are passing the whole model through and you want to pass an individual list item in.
So you need too loop through the model like this:
foreach(var item in Model)
{
#RenderPage("~/Views/Todo/Create.cshtml", item)
}
Simply create a view model class like this:
public class ToDoViewModel
{
public IEnumerable<ToDo> Todos{ get; set; }
public ToDo NewToDoItem { get; set; }
}
Then change your contoller's action:
public ActionResult Index()
{
var todoViewModel = new ToDoViewModel();
todoViewModel.NewToDoItem = new Todo();
todoViewModel.Todos= db.Todos.ToList();
return View(todoViewModel);
}
And then adjust your Index view:
#model ToDoMVC.Models.ToDoViewModel
#RenderPage("~/Views/Todo/Create.cshtml",Model.NewToDoItem)
A view inside a view or inother words, a nested view is not viable as far as my affair with MVC goes. You create a view and bind it to a model to show data relevant to that model on the browser. Now if you want data from other multiple models / business entities to be rendered on the view then you use ViewModels (Reference 1,Reference 2) and for that matter, the answers above remain valid. You can also customize / define sections on your layout to render specific information aswell. Partial views also make an option depending on the kind of info you want delivered to the view.
You can create a MasterModel and refer it to index view
public Class MasterModel
{
Public IEnumerable<ToDo> TodoList { get; set; }
Public ToDo CreateModel { get; set; }
}
Controller
public ActionResult Index()
{
MasterModel model = new MasterModel();
model.CreateModel = new Todo();
model.TodoList = db.Todos.ToList();
return View(model );
}
Refer this to Index model
#model MasterModel
#RenderPage("~/Views/Todo/Create.cshtml",Model.CreateModel)

Passing Data From View back to the HttpPost method in MVC

Alright so i want to pass data from the view back to Post Method in the controller.
The View :
#model IEnumerable< MvcMobile.Models.Trips>
<p>Time : #ViewBag.titi</p>
<p>ID :#ViewBag.iid </p>
<p>From : #ViewBag.From</p>
<p>To :#ViewBag.To </p>
Avaibliabe Trips :
#foreach (var item in Model)
{
if ( item.Time==ViewBag.titi)
{
<p>#item.TripID</p>
}
}
My HttpGet Method in the controller :
[HttpGet]
public ActionResult Book2(MvcMobile.Models.TicketsBooked tik)
{
ViewBag.titi = tik.Time;
ViewBag.iid = tik.TicketID;
ViewBag.from = tik.From;
ViewBag.To = tik.To;
var TripsList = db.Trips.ToList();
return View(TripsList);
}
In This case i cant use a dynamic object to pass variable since the model is IEnumerable
i want to pass one or two textBoxes back to the controller, how can i do that ?
an alternative question would be how can i do the same functionality in the view without making the model IEnumberable ?
and thanks alot.
You should read up on using view models. Basically it's best practice to only pass relevant data to the view. So instead on passing a model of IEnumerable you would have a view model with a property of IEnumerable plus the extra properties you want to post back to your controller.
So for example:
public class ViewModel
{
public IEnumerable<MvcMobile.Models.Trips> Trips { get; set; }
public string ExtraValue { get; set; }
}
and your view would be:
#foreach(var trip in Model.Trips)
{
<p>Do stuff</p>
}
#Html.TextBoxFor(m => m.ExtraValue)
Your post method would then accept a ViewModel.
[HttpPost]
public ActionResult Book2(ViewModel viewModel)
{
}
You can read up more on view models here or by searching Google / SO. There are many, many examples.

How do I add a Custom Query for a drop down and retain the View Model Pattern?

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>

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