razor - Cascading dropdown lists in ASP.NET MVC 5

Question

I am wondering if there's some new helper or method introduced in ASP.NET MVC 5 to implement cascading dropdown lists. I know a way to implement cascading dropdownlist behavior in MVC 3 and MVC 4 that is by using a JSON call

http://www.dotnet-tricks.com/Tutorial/mvc/HL53191212-Custom-Validation-for-Cascading-Dropdownlist-in-MVC-Razor.html

So anyone knows a better way to implement cascading dropdownlists in MVC 5?

Answer 1

I know that this is an old question but somebody still may find it useful

I was searching for the same thing but din't find anything stable and useful so I ended up implementing it by myself:

Please take a look at Mvc.CascadeDropDown helper that I created. It works with all MVC versions starting from MVC3 and doesn't require any client side libraries(It uses plain vanilla JavaScript).

The usage is very simple:

@using Mvc.CascadeDropDown

//First simple dropdown 
@Html.DropDownListFor(m=>m.SelectedCountry, Model.Countries,
      "Please select a Country", new {@class="form-control"})

//Dropdown list for SelectedCity property that depends on selection of SelectedCountry property
@Html.CascadingDropDownListFor( 
  expression: m => m.SelectedCity, 
  triggeredByProperty: m => m.SelectedCountry,  //Parent property that trigers dropdown data loading
  url: Url.Action("GetCities", "Home"),  //Url of action that returns dropdown data
  actionParam: "country",   //Parameter name for the selected parent value that url action receives
  optionLabel: "Please select a City", // Option label
  disabledWhenParrentNotSelected: true, //If true, disables dropdown until parrent dropdown selected
  htmlAttributes: new { @class = "form-control" }) //Html attributes

Hopefully it will be helpful for some of you