The "Unnamed" scope is
equivalent to the "Variables" scope in all other CFM pages (in fact, in
RedSky Variables will be fixed to allow its use in the same way in CFCs [this is public info now, right?]).
It is "private" to a given instance of
the CFC. (It is not truly "private" in the java sense of the word, but
there's no reason to confuse matters with that discussion
here.)
Personally, I have not yet found a time when you'd say
"this.firstName". I subscribe to the notion that instance data should
be private and accessed via methods rather than exposed directly -- if you
want to say myComponentInstance.firstName then why not just use a
structure? Also, see my previous post for some of the reasons it's a
"good thing" to not expose your instance data directly.
As for
this.methodName() -- the only time I can imagine that is necessary is if you
have two methods with the same name, one is private and the other is public
(which, last I checked, was allowed by the compiler -- though, it might not
be any more). But, personally that sounds like a bad idea in the first
place -- I have never found a need to say this.methodName() as opposed to
just methodName().
Now, I
am not alone in opposing the use of "this", but I am also not speaking for
everyone. In fact, the official documentation about CFCs shows using
"this" for your instance data. Several articles I've seen written
about CFCs show using "this". I'm not as religious as some about
preserving the object metaphor and strict encapsulation, but I don't think
you can go wrong by sticking with private data instead of using
THIS.
HTH.
-
Nathan
(comments, conversation interspersed)
| > Sparrow-Hood, Walter:
|
>
| > First of all I'd like to thank the
regular contributors to this
| > list.
I've been monitoring the discussions for the last
| > month or two and it has been extremely useful for someone
| > like me who is struggling to use CFCs
correctly but who
| > doesn't have a background
in Java or OOP
I'll echo that statement very loudly. Thanks for all the
help you've given me, folks, whether or not you've known you've
been.
| Nathan Dintenfass:
|
| ...if you want to be formal about it, you
shouldn't even have a publicly
| accessible
property called "name" (and you avoid that by NOT using "this"
| for your instance data -- instead use the unnamed scope
[some use a
| "virtual" scope, as discussed in
previous posts]).
What I can't really understand at this point is the
difference between the "this" scope and the
unnamed-scope-that-really-isn't-a-scope (or a virtual "instance" scope).
When would it ever make sense to use this.propertyName? How about invoking
other methods of the same component: this.myOtherMethod() or just
myOtherMethod() ?
Or is the answer to this question so preference-based that
either it isn't possible to choose a way, or it doesn't matter if you do
choose, except in the case of internal standards?
Thanks again, all.
--
Eric C. Davis
