ASP.net MVC - Views and jQuery Best Practices

Question

I'm trying to figure out what the best practice is for using jQuery in an MVC app. Specifically, I would like to know what I should do so that I don't clutter all my views with individual document.ready statements.

As an example:

I have the following Views:

/Views/Shared/_Layout.cshtml
/Views/Home/Index.cshtml
/Views/Home/_Dialog.cshtml
/Views/Home/_AnotherDialog.cshtml

I have a controller action that will render the Home/Index View, which uses the Layout and renders two partial views (or editor templates, display templates, etc.). This one controller action has rendered 4 or more views. Each view is using some jquery document.ready code.

Currently, I have the code at the bottom of each view:

// In Index
<script type="text/javascript">
    $(function() {
        $('#tabs').tabs()
    });
</script>

// In _Dialog
<script type="text/javascript">
    $(function() {
        $('#some-dialog').dialog( ... );
    });
</script>

I know this isn't a very good practice because it is already getting unmanageable in my small project. What are some good practices to follow when I have tons of pages that all need some jQuery / javascript initialization code separated across dozens of views?

Answer 1

You could do something along the lines of what Telerik do with their javascript registrar. Basically, make this registrar available in your view model. At the simplest level, all it has to do is keep track of strings added to it:

public class JavascriptRegistrar
{
    private StringBuilder jsBuilder_ = new StringBuilder();

    public Add(string js)
    {
        builder.Append(js).Append('\n');
    }


    public string ToString()
    {
        return "<script type=\"text/javascript\">" + jsBuilder_.ToString() + "\n</script>";
    }
 }

Your partial views will then add to this when rendering:

<h1>In my view!</h1>

@Model.Registrar.Add("$function() { /* ... */ }")

Finally, at the bottom of your main view, when you're done:

@Model.Registrar.ToString()

Which will write out all the javascript it has collected during rendering.

Answer 2

If the initialisation is specific to a view and you know it definitely won't be used outside that view, for example some page specific behaviour, then just leave it in the view!

There is nothing wrong with having script tags in all your views, as long as you aren't replicating js between views. I think people tend to misunderstand 'separation of concerns' in this case and think that simply means 'keep different languages away from each other at all costs'...that is wrong, clearly if some page initialisation logic/behaviour is specific to a page, then the html and js intrinsically 'concern' each other, therefore moving the js into a separate file is not really 'good practice', if anything it makes your code more difficult to understand.

I personally like to open up a View, and be able to see all the js and css that is specific to that page as soon as I open it, makes it nice and readable. However, obviously if code needs to be shared then you need to bust it out your view and get in your scripts folder whwere it can be referenced by anything!

EDIT

In your example above I see in your Index view you initialise your tabs. This is fine as it is, however, if you added tabs somewhere else in the project then it might be better to create your tabs using a .tabs class rather than #tabs id, and then in an external js file initialise all your tabs at once by calling $('.tabs').