Question

I am still in the process of learning the ASP.NET MVC3 Razor engine, and I’m trying to wrap my head around how to accomplish something that seems so incredibly simple.

I have a static class that encapsulates a method which calls a third party API. My _Layout.cshtml master page calls the static class, e.g.

if(@Rf.Models.PageContent.GetSomething().IsSomethingHappening) {
   <span>@Rf.Models.PageContent.GetSomething().Name</span>
}

As you can see I am duplicating effort (and a call to the third party API) from my static class PageContent, method GetSomething — which returns a class.

In regular old MVC2, I would have done something like this:

<% var obj = Rf.Models.PageContent.GetSomething();
   if(obj.IsSomethingHappening) { %>
   <span><%=obj.Name%></span>
<% } %>

…which doesn’t duplicate effort.

I want to call PageContent.GetSomething() once, store it, and reference it if my flag is true. I do not want to call PageContent.GetSomething() again, if my flag is true.

This may be a very simple question, but I’m a bit stuck on how to accomplish it. How can I duplicate the same kind of functionality from within the Razor engine?

Answer 1

The equivalent in Razor would be:

@{
    var obj = Rf.Models.PageContent.GetSomething();
}

@if (obj.IsSomethingHappening)
{
    <span>@obj.Name</span>
}

Obviously having views to pull data from static methods is one of the ugliest and anti-MVC practice. Views shouldn’t pull any data. They should only use data that was provided to them by the controller.

So here’s the correct way to do this:

public class FooController: Controller
{
    public ActionResult Index()
    {
        var obj = Rf.Models.PageContent.GetSomething();
        return PartialView(obj);
    }
}

and in the corresponding view (~/Views/Foo/Index.cshtml):

@model AppName.Models.SomeViewModel
@if (Model.IsSomethingHappening)
{
    <span>@Model.Name</span>
}

and to call this from your _Layout simply:

@Html.Action("Index", "Foo")