I am using ASP.NET MVC 2.0 and I want to transfer my ViewModel properties to business object. I can do this manually or use AutoMapper or use new method available in ASP.NET MVC 2.0. My question is that does anyone know the name of the new method which allows to copy the properties from one object to another?
I am having a trouble while trying to create an entity with a custom view modeled create form. Below is my custom view model for Category Creation form.
[code]....
When i click on save button, it doesnt bind the category for me because of i am using custom view model and strongly typed html helpers like that
Prior to using a ViewModel, I could easily pass the "soon to be edited" object directly to the view without needing to fuss over setting individual properties etc as the View conveniently accepted the Employee type directly..
[HttpGet] public ActionResult EditEmployee(int? id) { EmployeeRepository ER = new EmployeeRepository(); Employee SomeEmployee = ER.GetEmployee(id.Value); if(SomeEmployee!=null) return View(SomeEmployee);
But now I'm using a ViewModel with DataAnnotations attributes applied over the top of various properties for validation purposes. Which creates a problem.. After fetching the "soon to be edited" object from the db, setting the ViewModel's values is suddenly a whole lot more complicated. I can't simply pass the retrieved object straight to the view, as the View now expects the VMEmployee type instead. I would like to be able to do something like:
[HttpGet] public ActionResult EditEmployee(int? id) { EmployeeRepository ER = new EmployeeRepository(); Employee SomeEmployee = ER.GetEmployee(id.Value); if(SomeEmployee!=null) return View(new VMEmployee(SomeEmployee));
All paths seem to lead to a huge constructor which manually sets the values of each individual property. But I never had to do that before when I wasn't using a ViewModel. Model binding was a blessing! My objects also have complex child objects, which my form is also collecting values for, so this would be a huge/verbose task against DRY principals. I don't even really want to use a ViewModel, but am forced to because I need two different DataAnnotations rule sets for different validation scenarios applied to the same object.
All I want to do is be able to have two different DataAnnotations rule sets for different scenarios. I.e. public-facing www site vs internal-facing admin site. DataAnnotations doesn't seem to be flexible enough to easily cater for this common need. I've tried AutoMapper, but it throws an error saying it can't map my object types, I suspect because Employee was auto-generated by LINQ to SQL. What is the most elegant way to achieve this while sticking to DRY principals?
List<Category> Category is my database table having two properties Category_Id and Category_Name
and a strongly typed ProductCategoryViewModel View in which a ListBoxFor HtmlHelper is filled with Category_Name and Category_Id
public ActionResult Index(ProductCategoryViewModel model) { if (ModelState.IsValid)[code]....
In this Article is also my Database table defined in Linq to Sql classes. I want to get selected value and text from HtmlHelper ListBox to insert it to my Article table
I am a student at Millsaps College in Jackson, Mississippi and im working on my Senior Project. For my project i have chosen to use ASP.net MVC 2. Most things seem to be going well, but im having a real issue with the ListBoxFor() method. I have read a ton of posts on this website, StackOverflow as well as others. Here is a description of my problem.
One of the major points of my project is to create a directory of healthcare service providers in Mississippi. These providers can be sorted into multple categories, which creates a many-to-many relationship. Im using a ListBoxFor() to display those categories when the user would like to edit or create a provider. In the case of creation things work well. However in the case of editing an existing provider, i am unable to figure out how to get the providers's categories to be selected on the load of the page. Below is a look at some of the code. I would be so thankful to anyone who could help me tackle this issue
its said that 1 ViewModel has 1 View. 1 View is for me a UserControl. What if my UserControl has different areas filled with data from different entities, do I have then several Views and need to build several ViewModels? e.g: I display in a UserControl 3 entities: customer(listbox),order(datagrid),product(datagrid). Each of those "data areas" has add+remove buttons and textboxes to enter data.
Actually each of those "data areas" are put in its own GRID having so the posibility to set a individual datacontext.
1.) Should I now create 3 ViewModels CustomerVM,OrderVM and ProductVM? 2.) Are those 3 "data areas" seen as an own sort of separated View, although I have not put them in 3 UserControls.xaml files ??? 3.) When this one UserControl is inside a TabControl`s tabpage where do I load the 3 entities related data? Inside the MainViewModel? I want to show/load that data only when the user clicks the tabheader.
I'm new to .Net development, and now are following NerdDinner tutorial. Just wondering if any of you would be able to tell me What is the differences between ViewData and ViewModel(all I know is they are used to pass some form of data from controller to view) and perhaps tell me on what situation should I use ViewData instead of ViewModel and vice versa
[HttpPost] public ActionResult Edit(int id, FormCollection fc) { Movie movie = ( from m in _ctx.Movie.Include("MovieActors") where m.MovieID == id select m ).First(); MovieActorViewModel movieActor = new MovieActorViewModel(movie); if (TryUpdateModel(movieActor)) { _ctx.ApplyPropertyChanges(movieActor.Movie.EntityKey.EntitySetName, movieActor.Movie); _ctx.SaveChanges(); } return View(movieActor); }
However, I am not sure how to test this, and in general would much rather have the method take a typed model like:[HttpPost] public ActionResult Edit(MovieActorViewModel movieActor) Is this possible? What changes to my MovieActorViewModel class do I need to make in order to enable this? That class looks like this:
public class MovieActorViewModel { public Movie Movie { get; set; } public Actor Actor { get; set; } public PublisherDealViewModel(Movie movie) { this.Movie = movie; this.Actor = ( from a in this.Movie.Actors where a.ActorID == 1 select a ).First(); } }
The view is typed (inherits ViewPage) simple:
<% using (Html.BeginForm()) {%> Movie Title: <%= Html.TextBoxFor(model=>model.Movie.Title) %><br/> Actor Name: <%= Html.TextBoxFor(model=>model.Actor.Name) %> <% } %>
I have used IDataErrorInfo Validation for my Model.
But when I use these model classes inside a view model, the validation does not happen.
sample viewmodel below
[code]....
Now, if Category or Subcategory classes are directly used as models for view, the validation works fine. But, if CategoryViewModel is used, no validation occurs.
A table can be used to automatically sense Model. But when I get more than one table after the SQL query is a DataTable. When this DataTable to return View (DataTable) later. In the aspx file, can automatically perceive it as the Model, as the self-paragraphs?
But at the same time in this page I need to render some info from another ViewModel. Is it possible to write in action something like return View(Model1, Model2); ?And how could I get access to these ViewModels in this case?
This is probably basic stuff, but I can't find the clear answer anywhere..Lets say I'm doing an MVC (3) application with Entity Framework (EF4), and I have these three classes:
I have a table called "question" which consists of various columns, including 3 columns of type: bit.
these columns are: yes, no, maybe.
The corresponding viewmodel has 3 properties of type boolean. The controller returns the views, which are based on the viewmodels.
By default MVC create checkboxes for boolean types, the thing is that the properties have to be related, only 1 should be checked at a time. That is why I want to change the checkboxes to radiobuttons.
After some search on the web I tried various things, in the end I got the create working by putting three radiobuttons, tied to the same boolean field, adjusing the values.
But how to edit a question? The view is filled with data from the database, putting 1 of the 3 booleans to true.
What should my view be like, to display 3 radiobuttons, mapped to the 3 boolean types?
public class AccessRequestViewModel { public Request Request { get; private set; } public SelectList Buildings { get; private set; } public List<Person> Persons { get; private set; } }
So in my application there must be at least 1 person for an access request. What approach might you use to validate? I don't want this validation to happen in my controller which would be simple to do. Is the only choice a custom validation attribute?
Edit: Currently performing this validation with FluentValidation (nice library!)
RuleFor(vm => vm.Persons) .Must((vm, person) => person.Count > 0) .WithMessage("At least one person is required");
http://weblogs.asp.net/shijuvarghese/archive/2010/02/01/view-model-pattern-and-automapper-in-asp-net-mvc-applications.aspxThat's Great, but it is in #C like every other tutorial I find. Note his ContactViewModelWell here is mine:
[Code]....
How do I add validation in the same fashion as he did in his blog in VB?
I'm curious as to what people consider better practice, between duplicating model structure in the view model and using a mapping tool to move data between the two, or aggregate the model inside the view model, i.e. have a property on the view model class that is a reference to the actual model. Which is considered a better approach in general?
I'm making an MVC2 app to manage billing schemes. These billing schemes can be of various types, e.g. daily, weekly, monthly, etc. and all types have their specific properties. My class structure looks like this:
public abstract class BillingScheme { /* basic billing scheme properties */ } public class BillingSchemeMonthly : BillingScheme { public string SpecificMonths; } //etc. for other scheme types
I retrieve a billing scheme through the base class using the billing scheme ID, and it gives me an object of the correct type. The property SpecificMonths maps to a database varchar field that contains a ;-separated string of month numbers. I want to split this to an array so I can create a list of checkboxes and I'd preferably do this with a facade property in a viewmodel. I could do it right inside the view but that seems to go against the MVC pattern.
The problem is I can only create this viewmodel specifically for a BillingSchemeMonthly, and I can't cast a BillingSchemeMonthly to a BillingSchemeMonthlyViewModel. I'd rather not implement a clone method in the viewmodel since the entire billing scheme is quite large and the number of properties may grow.
I am just getting started with MVC after many years of WebForms development.
I have a very simple page with two textbox fields, one called Input where a user will enter something, and one called Output where I want to return some string after they post the form, much like a postback scenario in WebForms. I have the View connected to a ViewModel for strong typing.
The ViewModel:
[Code]....
The View:
[Code]....
The Controller:
[Code]....
The problem I have is that the output text "Here is some response" never gets displayed, even though I modify the value in the HttpPost method and return the viewmodel to the view. Unless (just tried it) I set the textarea to disabled with:
[Code]....
Can someone explain this behavior? It seems as some "magic" assumes that whatever was in the input fields before the HttpPost should also be there after the post, similar to what ViewState does in WebForms.
but what if I wanted to bind to collection items within the ViewModel. I'm not sure if it's possible. Here's what I have:
My ViewModel:
[code]....
I'm getting the following error: Templates can be used only with field access, property access, single-dimension array index, or single-parameter custom indexer expressions.
Is there a way to stuff my ViewModel into an Ajax.ActionLink? edit I'd like to take my 5 search fields on my page which are bind to a view model and send it along my .ActionLink as my object value parameter.
I have a viewmodel with a property of a model class type. I set some properties in the model class to be able to show it to the user but then when I make a post, the model gets validated. How to overcome this? I don't want to enforce the DataAnnotations contraint in this case....
public class TheViewModel { TheModel TheModel { get; set;} } [code]...