Over a million developers have joined DZone.
{{announcement.body}}
{{announcement.title}}

Building MVC Select Lists The Easy Way

DZone's Guide to

Building MVC Select Lists The Easy Way

· Agile Zone
Free Resource

Speed up delivery cycles and improve software quality with TestComplete. Discover the most robust automated testing tool for end-to-end desktop, mobile, and web testing. Try TestComplete Free.

It is common to have a view model that contains a list of select list items ( IEnumerable ). However, I get a little annoyed when I see a select list item getting initialized like this:

Widgets = db.Widgets.FindAll().Select(x => new SelectListItem() { Text = x.Name, Value = x.Value });

Although this is legal syntax its just a little bit too ugly for my liking. In an effort to make life simpler I came up with the following helper class:

public static class SelectListFactory
{
    public static IEnumerable<SelectListItem> BuildList<T>(IEnumerable<T> items, Func<T, SelectListItem> func)
    {
        return items.Select(func);
    }        

    public static IEnumerable<SelectListItem> BuildList<T>(
        IEnumerable<T> items,
        Func<T, string> text,
        Func<T, string> value = null,
        Func<T, Boolean> selected = null)
    {
        return items.Select(x => new SelectListItem{
            Text = text.Invoke(x),
            Value = value == null ? text.Invoke(x) : value.Invoke(x),
            Selected = selected == null ? false : selected.Invoke(x)
        });            
    }        
}    

With the help of our new SelectListFactory we can now re-write that first block of code as:

Widgets = SelectListFactory.BuildList( db.Widgets.FindAll(), x => x.Name, x => x.Value );

Hmm, not to shabby. However, I think an extension method could make it even cleaner...

public static class SelectListExtensions
{
    public static IEnumerable<SelectListItem> BuildList<T>(
            this IEnumerable<T> items,
            Func<T, string> text,
            Func<T, string> value = null,
            Func<T, Boolean> selected = null
        )
    {
        return SelectListFactory.BuildList(items, text, value, selected);
    }
}

So now lets rewrite the method using our new extension method...

Widgets =  db.Widgets.BuildList( x => x.Name, x => x.Value );

Now that is considerably better than what we started with! Happy Coding!

Release quality software faster with TestComplete. Discover how to decrease testing times and expand test coverage with the most robust automated UI testing tool. Try free for 30 days.

Topics:

Opinions expressed by DZone contributors are their own.

THE DZONE NEWSLETTER

Dev Resources & Solutions Straight to Your Inbox

Thanks for subscribing!

Awesome! Check your inbox to verify your email so you can start receiving the latest in tech news and resources.

X

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}