SrkToolkit.Web-TempMessages.md

SrkToolit.Web - TempMessages enhancement

ASP MVC's TempData is great. It helps displaying messages to the user after a redirection (learn more).

What's wrong with TempData?

Nothing! Well... It's basic.

Simple message mechanism

What do you do with tempdata? Add confirmation messages after submitting a form, showing more details after redirecting the a different page.

This simple extension provides a model to have nice temp messages. A message is a piece of (localized) text, with a kind (info/error/warning/confirmation), that may contain HTML. The SrkToolkit.Web.Models.TempMessage class contains that.

public class TempMessage
{
    public string Message { get; set; }

    public TempMessageKind Kind { get; set; }

    public bool IsMarkup { get; set; }
}

Post messages

Now let's play. Let's look at a typical POST action.

using SrkToolkit.Web;

[HttpPost]
public ActionResult Save(MyModel model)
{
	if (this.ModelState.IsValid)
	{
        var result = MyDomainLayer.DoSomething(model);
        if (result.Success)
        {
		    // send a confirmation to the user
		    this.TempData.AddConfirmation("Entry saved!");
		    
		    // and a little tip
		    this.TempData.AddInformation("Don't forget you can always edit this entry again.");
		    
		    return this.RedirectToAction("Index");
        }
        else
        {
		    // show the error
		    this.TempData.AddError(result.ErrorMessage);
        }
	}

	return this.View(model);
}

You've got 4 methods to throw messages at the user. No more magical strings.

Display messages

See how easy it was to add many messages? Let's display that in our masterpage.

<ul class="tempdatagroup">
@foreach (var group in this.TempMessages().GroupBy(m => m.Kind))
{
    foreach (var item in group)
    {
    <li class="[email protected]">
        @if (item.IsMarkup)
        {
        @MvcHtmlString.Create(item.Message)
        }
        else
        {
        @item.Message
        }
    </li>
    }
}
</ul>

I usually use CSS to show well-visible eye-catching messages.