Menu
Assuming you wanted to develop your Controllers so that you use a ViewModel to contain data for the Views you render, should all data be contained within the ViewModel? What conditions would it be ok to bypass the ViewModel?
The reason I ask is I'm in a position where some of the code is using ViewData and some is using the ViewModel. I want to distribute a set of guidelines in the team on when it's right to use the ViewData, and when it's just taking shortcuts. I would like opinions from other developers who have dealt with this so that I know my guidelines aren't just me being biased.
612
All three objects are available as properties of both the view and controller. As a rule of thumb, you'll use the ViewData, ViewBag, and TempData objects for the purposes of transporting small amounts of data from and to specific locations (e.g., controller to view or between views).
In theory if properly implemented, the ViewBag would ultimately outperform the use of the ViewData dictionary because the binding of the expressions (e.g. ViewBag.
What is TempData and How to Use in MVC? TempData is used to transfer data from the view to the controller, the controller to the view, or from an action method to another action method of the same or a different controller. TempData temporarily saves data and deletes it automatically after a value is recovered.
ViewData and ViewBag are used for the same purpose -- to transfer data from controller to view. ViewData is nothing but a dictionary of objects and it is accessible by string as key. ViewData is a property of controller that exposes an instance of the ViewDataDictionary class.
Just to further Fabian's comment; you can explicitly ensure viewdata is never used by following the steps outlined in this article. There's really no excuse not to use models for everything.
If you have no choice but to use ViewData (say on an existing project); at the very least use string constants to resolve the names to avoid using 'magic strings'. Something along the lines of: ViewData[ViewDataKeys.MyKey] = myvalue; Infact, I use this for just about anything that needs to be "string-based" (Session Keys, Cache Keys, VaryByCustom output cache keys, etc).
67
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
