Client vs Session vs Cookie Variables

ProjectedSurplus wrote:
> Yes, definitely NOT a repeat every request strategy.
>
> However, what is the root of the issue is that I want to remember the user's
> settings upon their next visit.
>
> As such don't I still need to write the info to either a CLIENT.var or a
> COOKIE.var upon session end?
>
> (To me doing so would both allow remembering of visitor choices and reduce
> dbase pings)
>

Yes, something would need to be written to a cookie. You could store
the entire data set if you choose. There are challenges but they are
not unsurmountable. There are also some limits The solution would
depend somewhat on how much data you want to store.

For a few simple keys and values you could just make a separate cookie
for each. Otherwise you could serialize a complex variable either
manually or with something like the <cfwddx...> tag.

The latter is very hand, but rather verbose, so if you are working with
a lot of data you may want something leaner so that you don't run into
problems with maximum cookie size, which was about 4K if I recall
correctly and has not changed since I last paid attention to it.

But personally, making a single database call once each time a visitor
starts a session against a well defined and optimized database is not
very stressful on a system.

It may be relevant that one way or another cookies are going to be used.
Whether you manage them and their content or not -- cookies are the
*only* way to maintain user state between http requests. Either you
create them or ColdFusion will if you go with a straight forward client
or session scope for your data scope.

Yes, definitely NOT a repeat every request strategy.

However, what is the root of the issue is that I want to remember the user's settings upon their next visit.

As such don't I still need to write the info to either a CLIENT.var or a COOKIE.var upon session end?

(To me doing so would both allow remembering of visitor choices and reduce dbase pings)

You may be over thinking this.

Why don't you want to use session variables. Most people *want* to put
as much into memory as possible to eliminate as much database and file
system calls as possible. Obviously this needs to be balanced with
system capabilities and site traffic, but in general memory is better
then database is better then file IO.

The way this is usually done is that a cookie value is used to store a
user ID. This ID is then used to retrieve user state from a permanent
store of your choice. Placing this data into session memory during the
visit of the user.

Or, what about using the onRequestStart or onRequest methods of Application.cfc?

Another thought is to use the cgi.HTTP_referer to determine if visitor is coming from outside (hence in need of ip-to-GUI component) OR if they are coming from another page of mysite (and hence not in need of a new trip to that cfc/dbase if the info is already available in say a client variable)

Anyone with any experience in this sort of thing?

As a further point, at present I have a <cfinvoke> at the top of my index page which calls the component -- but without using frames (for reasons of my own) this infers that literally every page calls the IP-to-GUI component everytime.

I have learned that flash/flex has the ability to store the data in a shared object (and then only send the info when instructed to do so vs. with every request like a cookie.var does).

Ideally though in HTML (too fwiw) I only want to invoke this component on first visit or on change. I'm currently reading up on the onSessionStart method of the Application.cfc file ("This is a special method run only at the beginning of a user's session. Conversely, it may be handy to notice when a user's session end via onSessionEnd method") with thoughts of writing the cookie onSessionEnd and reading&deleting onSessionStart.

Thoughts??