Simple example to show the difference between IBAction and IBOutlet.

This code is made in Xcode and it use AppleScript AppDelegate Template.
It demostrate the difference between IBAction and IBOutlet with an slider.

In short the slider send a action to property handler. The property handler get the intValue.
We make a connection between the slider and AppDelegate by picking the property handler.

We have the intValue now we need to make reference in Interface Builder IBOutlet by
making a connection from text field and choose Referencing Outlet to App Delegate.

buttonAction is only to check/debug a value or anything.

Ps. You need Xcode to follow this guide.

--  AppDelegate.applescript
--  Dialog
-- Xcode: Make a label, slider, text field and button
--      mark button -> right click -> drag sent action to App Delegate -> buttonAction
--      mark slider cell -> right click -> drag sent action to App Delegate -> sliderAction
--      mark text field cell -> right click -> drag Referencing Outlets to App Delegate 
script AppDelegate
	property parent : class "NSObject"
	-- IBOutlets
	property theWindow : missing value
    property sliderValue : missing value
    property theNumber : missing value
	on applicationWillFinishLaunching_(aNotification)
		-- Insert code here to initialize your application before any files are opened 
	end applicationWillFinishLaunching_
    on sliderAction:sender
        set theNumber to sender's intValue()
        sliderValue's setStringValue:theNumber
    end sliderAction:
    on buttonAction:sender
        display alert "Slider 1: " & (its theNumber)
    end buttonAction:
	on applicationShouldTerminate_(sender)
		-- Insert code here to do any housekeeping before your application quits 
		return current application's NSTerminateNow
	end applicationShouldTerminate_
end script