Creating Objects from CFCs

Actually there are good reasons for both methods of setting variables.

The first method, setting the variables outside of any functions, is used when there will NEVER (or very very nearly never) be a need to change them. Of course these could and should be set during the application initialization and the components just pull from there. BUT for portability you may want to put the data inside.

The init() allows you to create different instances of the same component, like maybe "product" and you pass in the specs on that instance.

jeby wrote:

> I am assuming that they are accomplishing the same task.
>
> If someone can explain the differences between these two methods and if there
> are benefits to either one it would be greatly appreciated. Thanks!

Nearly but there is a subtle difference. Code, such as these initial
variable sets inside the <cfcomponent...> block, but NOT inside a
<cfunction...> block, is a ColdFusion Component's version of a
constructor. This code is always run when a component is instantiated.
But you may notice that there is no way to pass arguments to this code
when it is run at the time of creation. The ColdFusion community has
developed the 'init' function as a defacto standard to create a pseudo
constructor to which one can pass arguments.

The init function is not a true constructor, it is not automatically
called during creation of the object, rather it must be implicitly
called by the developer. Thus in your example, the code in the
<cfcomponent...> block would automatically be run every time an object
is created. The init function would only be run when told to by the
developer during run time.

This is often done with a daisy chain command so that the actions follow
one, two. I.E. myObj =
createObject("component","path.to.my.component").init()

Again the reason for using this is to pass in arguments, so one would
usually see code like this:

<cfcomponent>
<cffunction name="init" ...>
<cfargument name="var1"...>
<cfargument name="var2"...>

<cfset THIS.var1=arguments.var1>
<cfset THIS.var2=arguments.var2>
</cffunction>
</cfcomponent>

----------

myObj = createObject("component","my.component").init("lala","toto")

PS. Also must developers would put these values into the 'VARIABLES'
scope rather then the 'THIS' scope. The 'Variables' scope is private to
the component|object, the 'This' scope, on the other hand, is public.

HTH
Ian

I think the following link has a good sample. :)

http://cfoop.org/readArticle.cfm?aid=3