lessons learned or mistakes made when using asp.net mvc

Don't forget the "Unit Tests" part of the pattern.

Try to always use a ViewModel to pass data between the Controller and the View. You may think you don't need one, you can just pass your model around, but suddenly you need a list box with several options for editing a model, or displaying a message (not validation message) and you start adding items to the ViewData, with magic strings as keys, making the app harder to maintain. There are also some security issues that you solve with a ViewModel. For instance:

class user:
int id
string name
string email
string username
string password

Your view let's the user change his name and email and posts to the action

public ActionResult Edit(User user)
{
--persist data
}

Someone could tamper your form and post a new password and username and you will need to be very careful with the DefaultBinder behavior. Now, if you use a ViewModel like:

class userEditViewModel:
int id
string name
string email

The problem is gone.

• Whenever it is possible make your view typed

• Avoid logic in your views

• stay away from the HttpContext

1. Get Steve Sandersons Pro ASP.NET MVC Framework

2. Debug into the Sourcecode

• If you make a Controller method with a different parameter name from id for a single parameter method, you have to make a new route. Just bite the bullet and use id (it doesn't care about the type) and explain it in the comments.

• Makes sure you name your parameters with RedirectToAction :

  return RedirectToAction("DonateToCharity", new { id = 1000 });

• You lose your ViewData when you RedirectToAction.

Put javascript in seperate files, not into the view page

name of the controller :)

unit test Pattern

Don't use the Forms collection, use model binding.

Try not to use ViewData, create a ViewModel.

If you have a loop or an if in your View, write an HTML helper.

Kindness,

Dan

Don't let your controller become a fat one and do too much work. I've seen 1000+ line controllers in the past and it just becomes an absolute nightmare to understand what's going.

Utilise unit testing for your controllers to ensure that dependencies are kept under control and that your code is testable.

Don't get drawn into letting jQuery and fancy clientscript define the behaviour of your application, try and use it as sparingly as you can and let it enhance your application instead.

Use partial views and HTML helpers whenever possible to ensure that your Views do not become unwieldy and a maintenance nightmare.

Use a ViewModel whenever possible.

Use a dependency injection framework to handle your dependencies (MvcContrib has several controller factories, though it's simple enough to roll your own).

Use a different controller for every section of your site (e.g., Home, Account)

Learn how to use ViewData and TempData

Learn what's the use of RenderPartial