How do I create composite views in ASP.Net MVC 3?

How do I create a view in ASP.Net MVC 3 that defers creation/rendering of a portion of the view to another view/controller, without knowing at design time what view/controller will be deferred to?

I have a Dashboard view/controller that uses a Layout page. the dashboard view does most of the work of rendering the overall screen. However a certain placeholder section of the overall screen will differ based on business rules, configuration, user interaction etc. There are three separate plugin views/controllers that may need to be rendered in the placeholder section. How do I instruct the Dashboard view to render a specific开发者_如何学JAVA plugin view once the Dashboard controller has determined which plugin should be visible. I have accomplished this already by putting flags in the Dashboard model and then having conditional logic in the Dashboard view call Html.RenderAction with the appropriate parameters based on the flags. This seems unsatisfactory and I would assume there is already a simple built in functionality for this kind of scenario, please advise.

Thank you

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You are really asking "how do I dynamically render partial views who's identity is known at design time."

One can get there two ways, either through Html.RenderPartial or Html.RenderAction. And both have their place. If the main page "knows" enough to have the view data, then RenderPartial is your the better bet as it is a bit more efficient than RenderAction. If you only know, say, a unique identifier for your portal widget than RenderAction works because you've now got a fully capable controller method that can do things like go back to a database and render a view.

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You could write your own htmlhelper and use that in your view instead of using the flags.