Maybe I'm complicating this but you will enlight me for sure.
Imagine a page where a list is displayed. That list is paged. I specify the list displays 30 items, therefore the controller returns my 30 items and the view renders the 30 items. My question is: both the controller and the view need to know the 30 setting. Where should it be stored? Web.config? I'm thinking if sharing configs via web.config that are used across "layers" is a good practice...
Tks in advance
Web.config is fine. Have you considered allowing the page length to be dynamic, perhaps based on a querystring value? (either way, you'll still need a default stored or hard-coded somewhere)
Also, I'm probably parsing words here, but you don't want your view to explicitly know of this setting (ie, accessing the web.config value directly). It should just iterate the list of items that the controller passes it, regardless of quantity.
I don't think what you're describing is violating separation of concerns. By design data is shared across the layers of an MVC application, since the view has to get the data one way or another.
What you shouldn't do is have the view know how to get the data. In other words, your view shouldn't know where that "30" setting is coming from, so that you can change it in the future without changes necessary to the view.