Tip of the Iceberg

Category show-n-tell thursday
One characteristic now common to several popular Javascript libraries (such as Mootools, jQuery, and the newly updated Prototype) is the ability to chain methods: that is, to do several things to or with an object in a single line of code. For example:

Clown.makeBalloonAnimal().rideUnicycle().frightenSmallChildren();

This appeals to many of us because, well, we're lazy. That's not a bad thing - the point of code is to make some task or process easier for users; so why not structure code in a way that makes it easier to reference that code later on?

Anyhow, what makes this possible in Javascript is that all methods are functions. Even what LotusScripters would consider a Sub. Which means that all methods have a return value, even if none is explicitly specified. A chainable method, then, is simply a function that returns an object (typically the instance containing the method).

In LotusScript, this is easily accomplished by making each Sub a Function instead and using the keyword Me:

Public Class Clown
	Public Function makeBalloonAnimal() As Clown
		'Method statements
		Set makeBalloonAnimal = Me
	End Function
	
	Public Function rideUnicycle() As Clown
		'Method statements
		Set rideUnicycle = Me
	End Function
	
	Public Function frightenSmallChildren() As Clown
		'Method statements
		Set frightenSmallChildren = Me
	End Function	
End Class

All methods of the class are now chainable:

Sub Initialize
	Dim Bozo As Clown
	
	Set Bozo = New Clown()
	Call Bozo.makeBalloonAnimal().rideUnicycle().frightenSmallChildren()
End Sub