How to Post Partial View Data? - asp.net-mvc-3

Any input much appreciated :)
I want to know one thing whether I can post multiple partial views data in MVC?(means i want to update partial views data to DATABASE)
Here is the Example:
Model:-
public class PassengerViewModel
{
public List<PassengerModel> Passengers { get; set; }
public ContactModel Contact { get; set; }
}
Controller:-
[RequiredAuthentication]
public ActionResult Passenger()
{
var passengrViewMdl = new PassengerViewModel()
{
Contact = new ContactModel(),
Passengers = psngrService.LoadPassengers(Convert.ToInt32(Session["LPORefNO"]))
};
return View(passengrViewMdl);
}
[HttpPost]
public ActionResult Passenger(PassengerViewModel passengerViewModel)
{
Here i want to update Passengers & Contact information
}
View:-
#model QR.LPO.Core.Models.PassengerViewModel
#{
ViewBag.Title = "Add Passengers";
}
#using (Html.BeginForm())
{
#Html.Partial("_Passenger", Model.Passengers);
#Html.Partial("_PassengerContact", Model.Contact);
<input type="submit" value="Submit" />
}
Thanks.

Yes, indeed you can, but, controller usually works only with one model per request, so either your model should have declared within it properties of both partial submodels, or submodels themselves.
This is possible due to HTML specifications, all data on form, which has submit buttom is send to submit action url.

This will almost work as you have it - there's nothing inherent to partials that would prevent this, in the end the html that's output is all that's important.
The problem with your code is that presumably the model of your _Passenger view is of type Passengers and the model of your _PassangerContact view is of type Contact. What this means is that if you standard HtmlHelper extensions (like Html.Textbox(...) or Html.TextboxFor(...) the fields they generate will not have full names like Contact.Name, but instead just names relative to their model, like Name. This will cause modelbinding to fail in your post action.
You can solve this in a number of ways.
Simply use the same model type (PassengerViewModel) in your sub-views, and write code like #Html.TextboxFor(m => m.Contact.Name).
Instead of using Html.Partial, use Html.EditorFor(...). This passes the proper prefix information into the child view so the field names are generated properly.
Explicitly set the prefix yourself
Like this:
#{
var childViewData = new ViewDataDictionary(this.ViewData);
childView.TemplateInfo.HtmlFieldPrefix = "Contact";
}
#Html.Partial("_PassengerContact", Model.Contact, childViewData)
You could also look at creating a Html.PartialFor overload yourself, as described in this stackoverflow question: ASP.NET MVC partial views: input name prefixes

Related

Model not updated from view to controller

I'm trying to do that:
Create a Model, add it on a session and send it to the view.
Change Model fields on my view
Get the Model from session updated on my controller
The problem is that my model is never updated when I'm changing values on textboxes, I'm sure that I'm missing something with razor,
View:
#model MvcTestApp.Models.Car
<div class="b1">
<div class="b2">#Html.EditorFor(e => e.KM)</div>
<div class="b2">#Html.EditorFor(e => e.RegistrationNumber)</div>
</div>
#Html.ActionLink("Car", "sendCar")
Controller:
On SendCar, I would like to get the model updated.
namespace MvcTestApp.Controllers
{
public class CarController : Controller
{
public ActionResult Show()
{
var model = new MvcTestApp.Models.Car()
{
RegistrationNumber ="12345",
KM = "12345"
};
Session["temp"] = model;
return View("Show",Session["temp"]);
}
public ActionResult sendCar()
{
return View("Show", Session["temp"]);
}
}
}
Model:
namespace MvcTestApp.Models
{
public class Car
{
[DataType(DataType.Text)]
public string KM { get; set;}
[DataType(DataType.Text)]
public string RegistrationNumber { get; set;}
}
}
You need to make your sendCar controller to update the model. Currently, all the changes you do will only persist locally until you navigate away from the page. You need to post the changed model back to the server.
Take a look at the "Handling edits" part of this example to see how it can be done:
Asp.net tutorials
The way to do this is by wrapping your model details in a form with a submit function. Then in your sendCar method take in a Car object and the model binding will take care of setting everything on the new object.
If you're wanting to persist this (I assume this is just for testing purposes?) then perhaps make your car that you're returning in your show method a class variable.
You should read a beginner tutorial about ASP.NET MVC, which will explain you how to send data from a form to a controller, as it seems you are absolutely not aware of how to do this.
You are not missing 'something', you are missing all about sending data from forms to controllers.

A `ViewModel` for each page (`Create.cshtml` and `Edit.cshtml`)?

Questions
There are actually two related questions:
Should I create a ViewModel for each page?
If you do not have problems in creating a single ViewModel class for the two pages (Create.cshtml and Edit.cshtml) how can I validate the ViewModel in different ways (depending on the page that is being used)
Source
ViewModel
public class ProjectViewModel
{
public string Name { get; set; }
public string Url { get; set; }
public string Description { get; set; }
}
Edit.cshtml
#using BindSolution.ViewModel.Project
#model ProjectViewModel
#{
ViewBag.Title = Model.Name;
}
#Html.EditorForModel()
Create.cshtml
#using BindSolution.ViewModel.Project
#model ProjectViewModel
#{
ViewBag.Title = "New Project";
}
#Html.EditorForModel()
ProjectValidator.cs
public class ProjectValidator : AbstractValidator<ProjectViewModel>
{
private readonly IProjectService _projectService;
public ProjectValidator(IProjectService projectService)
{
_projectService = projectService;
RuleFor(p => p.Name)
.NotEmpty().WithMessage("required field")
/*The validation should be made only if the page is Create.cshtml. That is, if you are creating a new project.*/
.When(p => p.??) //Problem Here!!
.Must(n => !_projectService.Exist(n)).WithMessage("name already exists");
RuleFor(p => p.Url)
.NotEmpty().WithMessage("required field");
}
}
Note that if the user is editing an existing project, validation of the property name should not be done again.
ProjectController.cs > Edit method
[HttpPost]
public ActionResult Edit(Guid projectID, ProjectViewModel model)
{
var project = _projectService.Repository.Get(projectID);
if (ModelState.IsValid && TryUpdateModel(project))
{
_projectService.Repository.Attach(project);
if (_projectImageWrap.Create(project) && _projectService.Repository.Save() > 0)
return AjaxRedirect("Index");
}
return View(model);
}
Notes
If I create a ViewModel for each page, there is a duplication of code since pages have the same properties.
Add a property on the ViewModel indicating what page it is being displayed does not solve my problem as to instantiate the ViewModel, I use AutoMapper.
To validate the data, I use FluentValidator.
Thank you all for your help!
My understanding is that there isn't a 1:1 correlation between ViewModels and Views. Oftentimes you will have a View that will not require a ViewModel to go alongside with it.
You will want to create a ViewModel if and only if you need a Model absolutely paralleled and tailored to a specific View. This will not be the case 100% of the time.
When the functionality / use case /validation is different between the pages I use different models. If its the exact same besides the presence of an ID or something similar I use the same model, and its also possible to just use the same view if the differences are pretty minor.
Since your validation is different, if I were doing it I would create two different models so that I could use the out of the box DataAnnotations, with your validation though it may not be required. You could also on the edit model have a readonly property for name since its not editable any longer.
For me the same object must have the same validation on every time, in main to ensure the consistence of the object, independently if it was created or edited.
i think that you should create only one validation, and edit your "exists" method to pass to verify if it is a new object or the current object in repository.
Personally, I don't have a problem with 2 view models, especially if (as Paul Tyng suggested) you use a base class for the fields that are common to edit and create scenarios.
However, if you really only want a single view model then you would either need to:
add a flag to the view model and use the When() method in your validator. Note though that this will not generate the appropriate client-side only validation
define a second validator and invoke the appropriate one from the controller (i.e. instead of the "automatic" validation)
Provide another view Edit.cshtml which will allow the user to edit the data for a selected item.
Create another view Query.cshtml which based on the ItemName will allow the users to query the Inventory table.
Perform the calculation for the total profit (numbersold times (saleprice-purchasecost). Display the total profit.
(BONUS) Create another view Sell.cshtml that will indicate the sale of an item. Adding one to NumberSold and subtract one from NumberInventory for the selected record.

html.TextBoxFor and html.Textbox, POSTing values, model in parameters

Alright guys, Need some help!
Im working with asp.net mvc3 razor (and am fairly new to it but did lots of web forms)
Okay so onto the problem
My question revolves around submitting a view.
I have a very complicated model that my view is based off (strongly typed).
I want to return the model into the arguments in the HttpPost method of the controller. do basically:
public ActionResult Personal()
{
DataModel dataModel = new DataModel();
FormModel model = new FormModel();
model.candidateModel = dataModel.candidateModel;
model.lookupModel = new LookupModel();
return View(model);
}
[HttpPost]
public ActionResult Personal(FormModel formModel)
{
if (ModelState.IsValid)
{
//stuff
}
return View(formModel);
}
Now...
I'm having trouble getting values into the formModel parameter on the post method.
This works (meaning i can see the value)but is tedious as i have to write exactly where it sits in a string every single field:
#Html.TextBox("formModel.candidateModel.tblApplicant.FirstName", Model.candidateModel.tblApplicant.FirstName)
It renders like this:
<input name="formModel.candidateModel.tblApplicant.FirstName" id="formModel_candidateModel_tblApplicant_FirstName" type="text" value="Graeme"/>
This doesn't work:
#Html.TextBoxFor(c => c.candidateModel.tblApplicant.FirstName)
It renders like this:
<input name="candidateModel.tblApplicant.FirstName" id="candidateModel_tblApplicant_FirstName" type="text" value="Graeme"/>
Now I'm assuming the problem lies in the discrepancy of the id's
So please answer me this:
Am i going about this the right way
Why doesn't textboxfor get the right value/id, and how do i make it get the right value/id so i can retrieve it in a POST(if that is even the problem)?
Additionally, it seems that textboxfor is restrictive, in the manner that if you have a date time, how do you use the .toshortdate() method? This makes me think textboxfor isn't useful for me.
Quick clarification:
when i say textboxfor isn't working, it IS getting values when i GET the form. So they fill, but on the POST / submission, i can't see them in the formModel in the parameters.
Another side note:
None of the html helpers work, this is the problem. They aren't appearing in modelstate either.
Thanks everyone for the help
Answer:
html.TextBoxFor and html.Textbox, POSTing values, model in parameters
It was a problem in my view somewhere, i replaced all the code with the snippet in this answer and it worked.
Thank you again
Am i going about this the right way
Yes.
Why doesn't textboxfor get the right value/id, and how do i make it get the right value/id so i can retrieve it in a POST(if that is even the problem)?
There is something else in your code that makes this not work. It's difficult to say since you haven't shown all your code. Here's a full working example which illustrates and proves that there's something else going on with your code:
Model:
public class FormModel
{
public CandidateModel candidateModel { get; set; }
}
public class CandidateModel
{
public Applicant tblApplicant { get; set; }
}
public class Applicant
{
public string FirstName { get; set; }
}
Controller:
public class HomeController : Controller
{
public ActionResult Index()
{
return View(new FormModel
{
candidateModel = new CandidateModel
{
tblApplicant = new Applicant
{
FirstName = "fn"
}
}
});
}
[HttpPost]
public ActionResult Index(FormModel formModel)
{
// the username will be correctly bound here
return View(formModel);
}
}
View:
#model FormModel
#using (Html.BeginForm())
{
#Html.EditorFor(c => c.candidateModel.tblApplicant.FirstName)
<button type="submit">OK</button>
}
Additionally, it seems that textboxfor is restrictive, in the manner
that if you have a date time, how do you use the .toshortdate()
method? This makes me think textboxfor isn't useful for me.
I agree that TextBoxFor is restrictive. That's why I would recommend you always using EditorFor instead of TextBoxFor. It will allow you to simply decorate your view model property with the [DisplayFormat] attribute and voilĂ . You get any format you like.
For example:
public class MyViewModel
{
[DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
public DateTime CreatedAt { get; set; }
}
and in the view:
#model MyViewModel
#Html.EditorFor(x => x.CreatedAt)
will format the date exactly as you expect.
the model binder uses the name to bind the values to the model, and the html helpers e.g. Html.TextBoxFor uses the body of the lambda expression to set the name, however you can specify the name yourself which you are doing by using the Html.TextBox( helper
#Html.TextBoxFor(x=>x.candidateModel.tblApplicant.FirstName),
new{#Name="formModel.candidateModel.tblApplicant.FirstName"})
If your view is strongly typed, try the helper bellow, instead call each helper on each property
#Html.EditorForModel()
#Html.EditorFor(m => m.candidateModel)
#Html.EditorFor(m => m.lookupModel)
Update:
Well, have tried to use viewmodel to simplify this task? And when you get back the data you can map your real models. keep your views clean will give you less headaches in the future. Additionally you could use AutoMapper to help you.
Here a example if you think that will help you.
http://weblogs.asp.net/shijuvarghese/archive/2010/02/01/view-model-pattern-and-automapper-in-asp-net-mvc-applications.aspx

Using one Partial View Multiple times on the same Parent View

I am using MVC3 razor. I have a scenario where I have to use a partial view multiple times on the same parent view. The problem I am having is that when the Parent View gets rendered, it generates same names and ids of the input controls within those partial views. Since my partial views are binded to different models, when the view is posted back on "Save" it crashes. Any idea how can i make the control id/names unique, probably some how prefix them ?
Awaiting
Nabeel
Personally I prefer using editor templates, as they take care of this. For example you could have the following view model:
public class MyViewModel
{
public ChildViewModel Child1 { get; set; }
public ChildViewModel Child2 { get; set; }
}
public class ChildViewModel
{
public string Foo { get; set; }
}
and the following controller:
public class HomeController : Controller
{
public ActionResult Index()
{
var model = new MyViewModel
{
Child1 = new ChildViewModel(),
Child2 = new ChildViewModel(),
};
return View(model);
}
[HttpPost]
public ActionResult Index(MyViewModel model)
{
return View(model);
}
}
and inside the Index.cshtml view:
#model MyViewModel
#using (Html.BeginForm())
{
<h3>Child1</h3>
#Html.EditorFor(x => x.Child1)
<h3>Child2</h3>
#Html.EditorFor(x => x.Child2)
<input type="submit" value="OK" />
}
and the last part is the editor template (~/Views/Home/EditorTemplates/ChildViewModel.cshtml):
#model ChildViewModel
#Html.LabelFor(x => x.Foo)
#Html.EditorFor(x => x.Foo)
Using the EditorFor you can include the template for different properties of your main view model and correct names/ids will be generated. In addition to this you will get your view model properly populated in the POST action.
There is an alternative:
Add a prefix to the PartialView
Bind the model, removing the prefix
For 1, set the prefix in your View:
ViewContext.ViewData.TemplateInfo.HtmlFieldPrefix = "prefix";
For 2, you can recover the data with UpdateModel, like this:
UpdateModel(producto, "prefix");
This is not very advisable because your action doesn't receive the data as a parameter, but updates the model later. This has several inconvenients: 1) it's not clear what your action needs by looking at its signature 2) it's not easy to provide the input to the action for unit testing it 3) the action is vulnerable to overflow parameters (parameters provided by the user that shouldn't be there and are mapped to the model).
However, for 2 there is an alternative: register a custom Model Binder that allows you to do remove the prefix. And the custom Model Binder must know about it.
A good solution is in this SO Q&A: How to handle MVC model binding prefix with same form repeated for each row of a collection? But it has a little flaw: if you add a hidden field with the name "__prefix" in a partial view, and you render it several times as a partial view, this ID will be repeated for several different elements in the page, which is not allowed, and can provoke some trouble. And one of the most important reasons to provide a prefix is precisely rendering the same "edit" view as partial views for several instances of an entity. I.e. this would happen in a page like gmail, where you can edit several emails at once.
There are several possible solutions for this problem.
One of them is providing the prefix as a query string or routedata value, and not as a form field, which avoid the Id conflicts, and can be found by the model binder. (It can always have the same name).
Another solution is to use a hidden field, with a fixed pattern, but which is different for every rendered view. The prefix could follow this pattern for uniqueness: "PP$ActionControllerId" like "PP$EditProduct23", which is unique for each rendered view, and can be easily found between the request parameters looking for one that starts with "PP$".
And a final solution would be to create the prefix only in the view, and not providing it in any kind of request parameter. The Model binder would have to look for the prefix examining the names of the request parameters, until it finds one whose prefix follow the pattern.
Of course, the custom ModelBinder must be adapted to work tieh the chosen convention.

ASP.NET MVC 3 _Layout.cshtml Controller

Can anyone help me with the subject? I'm using Razor view engine and I need to pass some data to _Layout. How can I do it?
As usual you start by creating a view model representing the data:
public class MyViewModel
{
public string SomeData { get; set; }
}
then a controller which will fetch the data from somewhere:
public class MyDataController: Controller
{
public ActionResult Index()
{
var model = new MyViewModel
{
SomeData = "some data"
};
return PartialView(model);
}
}
then a corresponding view (~/Views/MyData/Index.cshtml) to represent the data:
#{
Layout = null;
}
<h2>#Model.SomeData</h2>
and finally inside your _Layout.cshtml include this data somewhere:
#Html.Action("index", "mydata")
You could use the ViewBag to pass data.
In your controller:
ViewBag.LayoutModel = myData;
Access in you layout:
#ViewBag.LayoutModel
It is a dynamic object, so you can use any property name you want.
The ViewBag method is the easiest. However if you need advanced and typed features, you can also try taking that part to a partial view (the part that'll render the dependent section) with a common controller (if the value can be calculated on it's own and doesn't need input from other controllers), and call RenderPartial on it from _Layout.
If you'd like I can give you some more info about it...

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