Q:

Using a system icon in a UIButton, in a UIToolbar?

I am trying to have a button, in a toolbar, use a system icon, by modifying its appearance in the XCode 7 interface builder. If I do this at the toolbar item level, then this just becomes a regular UIButtonBarItem, removing the button underneath. This means it won't send any press items, from what I can see.
I don't see a way on the UIButton, in the interface builder, to specify a system icon. Ideally I would like to avoid having to do this programmatically. Can anyone suggested a way?
Note, Apple indicates:

iOS provides a lot of small icons—representing common tasks and types
  of content—for use in tab bars, toolbars, navigation bars, and Home
  screen quick actions. It’s a good idea to use the built-in icons as
  much as possible because users already know what they mean.

Unfortunately it is not clear how to leverage them? Some sources indicate using "iOS-Artwork-Extractor", but I would hope there is another way to address this, maybe via some API call?
XCode 7.2.1, targeting iOS.

A:

For the UIButtonBarItem and the subset of icons available there (see table 41-1 in the iOS Human Interface Guidelines), to have it notify the code that it was pressed, then it is simply a question of adding an 'IBAction' function to the class corresponding to the view, for example (Swift):
@IBAction func flashItemActioned (sender: UIButton) {
   //
}

and then linking the "sent actions" of the item with the function in the first responder.
For UIButton based implementations I haven't found a solution beyond the "iOS-Artwork-Extractor".

