Hello All,
Recently Microsoft releases a second update for Visual Studio 2013 named Visual Studio Update 2 RC. Here RC means that it is in Release candidate version and you may expect few changes in the final version. But there are a list of changes they provided in ASP.NET MVC and Webforms that will be going to help a lot in your day to day coding. The new version of ASP.NET MVC is named as ASP.NET MVC5.1. In few of my coming posts, I’ll be discussing the major changes in ASP.NET MVC with examples.
So in this post, We’ll discuss few features of ASP.NET MVC5.1. ASP.NET MVC provides scaffolding that enables us to create the controller and views for our model. The controls on views are rendered based on the type of properties in the model but it is not true for all types. Say if you have property in your which is of type Enum then the UI generate the normal textbox for it which allows to enter free text which may become brutal to your application if it is not handled properly. To handle this scenario, I discuss that in one my old post, how you can extend EditorFor for custom type. You can refer the link
Html.EditorFor – Extend for custom type
But it requires lots of steps and require to handle various scenarios like displaying, editing etc which is error prone as well. Let’s take the same earlier example, I took a class as
public class Speaker { public int Id { get; set; } public string Name { get; set; } public bool IsAvailable { get; set; } public ExpertiseArea Area { get; set; } }
The enum type ExpertiseArea is defined as
public enum ExpertiseArea { ASPNET, Csharp, WindowsAzure, WCF }
Now when I created the Controller and Views via scaffolding as
and
and It created the controller and related views. Now lets run the application so it looks like as
Great!! Now you can see that expertise area is rendered as dropdown without any specific code. That’s fantastic.
Now let’s have a look on the cshtml page itself
@Html.EnumDropDownListFor(model => model.Area, htmlAttributes: new { @class = "form-control" })
So here, we find that there is a new helper method EnumDropDownListFor got introduced that is used for enum types. And this is used for on Create and Edit views because these views only allows user to edit or enter new data. Rest of the views are same as earlier.
This is very good feature that will help a lot to developers.For simple scenario it is fine, so let us discuss another scenario, where we dont want to show the actual enum value but we want to show some different value on the UI. So let’s add display attribute in enum as
public enum ExpertiseArea { [Display(Name = "ASP.NET")] ASPNET, [Display(Name = "C#")] Csharp, [Display(Name = "Windows Azure")] WindowsAzure, WCF }
Now again, let’s run the application and see the create page
It seems great, the value that populated in dropdown is what we put in display attribute. That’s what we want. Let’s add it and see the index page
Ohh.. this we did not expect. We expected that it should be C#. It means that it cannot be handled without just by simple scaffolding but it is required some custom code.
We’ll discuss this scenario in next part. Stay tuned!
Cheers,
Brij