You should see something with the code you posted assuming that the init method that calls this code is itself being called (and FooterButtonView is being displayed with a non-zero size). One thing you're missing though is the relative horizontal sizes of the two views. With the code you have, there's no way for the system to know what size each of the elements should be, just that they should take up the whole width minus the standard spacings. If you want the two views to be the same size, then change to this,
NSString* horizontalFormatString = @"H:|-[element1]-[element2(==element1)]-|";