Pass variable back from EditorTemplate to page or layout

Question

I am tired to google around and ddn't found the exact answer.

I know I can pass date from view to template by additionalViewData parameter of .EditorFor() or .DisplayFor() but I want a data back from template!

I have Date.cshtml in my ~/Views/Shared/EditorTemplates/. My model property already have something like this:

public class Person
{
    [DisplayFormat(DataFormatString = "{0:d}")]
    [DataType(DataType.Date)]
    public Nullable<DateTime> BirthDate { get; set; }
}

and the view:

@Html.EditorFor(model => model.BirthDate)

Now I want only to load datepicker script when ever the view uses the date template. So I try to use RequireDatePicker like this in my template:

@model DateTime?
@Html.TextBox(...)
@{ViewBag.RequireDatePicker = true;}

and in the bottom of _Layout.cshtml:

    @Scripts.Render("~/bundles/jquery")
    @if (ViewBag.RequireDatePicker == true)
    {
        <script type="text/javascript">
            if (!Modernizr.inputtypes.date) {
                // Todo: use Modernizr.load
                $(function () {
                    $("input[type='date']").datepicker();
                });
            }
        </script>
    }

The problem is I just realize ViewBag/ViewData has a different context from the view/partial and the display/editor template. What is the best way to do this?

---

Fix I can pass data from template back to view by route data like this:

@{ViewContext.RouteData.DataToken["requireDatePicker"] = true;}

However I end-up not passing the data but just this:

1. Have bundle "~/bundles/jqueryui" that

   • remove jquery ui date picker feature from it (and move to "~/bundles/jqueryui-datepicker")
   • include a Modernizr.inputtypes.date check and Modernizr.load to load "~/bundles/jqueryui-datepicker"

2. No need to modify _layout.cshtml to check for RequireDatePicker. @Scripts.Render("~/bundles/jquery") and @Scripts.Render("~/bundles/jqueryui") is enough sinec Modernizr.load is already included.

3. No need to pass RequireDatePicker from Date.cshtml to view or _Layout.cshtml as Modernizr.load

Answer 1

You could create dynamic javascript bundles like outlined in the following article

http://neimke.blogspot.co.nz/2011/12/composing-child-views-with-bundles.html

basically your editorfor template calls the following code

@{
  var bundle = Microsoft.Web.Optimization.BundleTable.Bundles.GetRegisteredBundles()
    .Where(b => b.TransformType == typeof(Microsoft.Web.Optimization.JsMinify))
    .First();

  bundle.AddFile("~/Scripts/DatePicker.js");
}

but you may want to replace the Where clause with one that finds a specific bundle instead, maybe one specifically for including javascript for child views.

If you wanted to go nuts, you could probably extend the razor view engine or WebViewPage to look for matching View.cshtml.js to every view that is rendered and add it to a bundle.