Pass compositioned data to views

use_inheritance.cs

// adding GeneralView class with IsCurrentUserAdmin bool field,
// Derive LayoutView from GeneralView
// Derive HomepageView and PostPageView from LayoutView

public ActionResult ViewPost(string permalink) {
  var post = magic.GetPostBy(permalink);
  var view= new PostView {Post=post};
  GetLayoutData(view);
  view.Related = magic.GetContentRelatedTo(post);
  Return View(view);
}

public ActionResult Homepage(){
  var posts = magic.GetRecentPosts();
  var view= new HomepageView {Posts=posts};
  GetLayoutData(view);
  view.Related = magic.GetContentRelatedToMany(posts);
  Return View(new HomepageView {Posts = posts});
}

private void GetLayoutData(LayoutView layoutView) {
  // called from each action, or with a Filter, whatever
  // but if we call this in a filter, how do we get an instance
  // of the view data instance
  layoutView.Archive = magic.GetArchive();
  layoutView.TagCloud = magic.GetTagCloud();
}
private void GetSharedData(GeneralView view) {
  // called from each action, or with a Filter, whatever
  // but if we call this in a filter, how do we get an instance
  // of the view data instance
  view.IsCurrentUserAdmin = magic.FigureThatOut();
}

use_the_view_data.cs

// stick data into the ViewData, then within the views, cast into the desired type

public ActionResult ViewPost(string permalink) {
  var post = magic.GetPostBy(permalink);
  ViewData["PostView"] = new PostView {Post=post};
  var layout = GetLayoutData(view);
  layout.Related = magic.GetContentRelatedTo(post);
  ViewData["LayoutView"] = layout;
  Return View();
}

public ActionResult Homepage(){
  var posts = magic.GetRecentPosts();
  ViewData["HomepageView"] = HomepageView {Posts=posts};
  var layout = GetLayoutData(view);
  layout.Related = magic.GetContentRelatedToMany(posts);
  ViewData["LayoutView"] = layout;
  Return View();
}

private LayoutView GetLayoutData() {
  var layoutView = new LayoutView();
  layoutView.Archive = magic.GetArchive();
  layoutView.TagCloud = magic.GetTagCloud();
  return layoutView;
}
private void GetSharedData(GeneralView view) {
  // called from each action, or with a Filter, whatever
  // but if we call this in a filter, how do we get an instance
  // of the view data instance

  currentContext.ViewData["IsCurrentUserAdmin"] = magic.FigureThatOut();
}