Reusing a xib with a uitableview connected via IBOutlet to a superclass: how is it better add a toolbar with a button only for some subclasses?

I have a xib with a uitableview in it. This table is connected via IBOutlet to a ViewController, root of a hierarchy of view controllers.

Now I have to add a toolbar with a button such that it isn't visible in all the views (controlled by subclasses of the root view controlle开发者_开发问答r).

How can I do it so that the table resizes properly?

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[urtoolbar setHidden:YES];

wherever u want to hide