foward/backward within hashes

[Anonymous Monk]

I have a script that views one element from a hash at a time using a url_param. Ie.

http://www.mysite.com/cgi-bin/employees.pl?id=Mon%20Jan%2026%2006:08:4
+8%202004

I'm using localtime so I can sort my hash in reverse timely order (though I can probably use an increment on the key as a $num++ and reverse that, but that's a different topic)..

If I am viewing id=Mon%20Jan%2026%2006:08:48%202004, is it possible to make a BACK button that when the user clicks it, it will show them the first previous dated hash? I want to be able to travel through all the database using back and forward buttons, any idea how this can be done?

An example of my hash looks like:

%people( "$time" => "$name|$email|$address");

And when you the url points at id=$time, I do a split on | and break it back into separate variables.

[BazB]

Create an array of hashrefs, sorted by the time.

Retrieve the next/previous array element as required, dereference the hash and display the information.

Update: Maybe I should explain why: hashes are effectively randomly ordered. By creating the datastructure I suggest, you sort only once, can figure out where in the sort order you are (the current array indice) and can easy retrieve other records with minimal processing (and thought).

[Limbic~Region]

Anonymous Monk,
The idea mentioned by BazB is pretty much what Tie::Hash::Sorted does under the covers. It would not be very difficult at all to add a method to allow you to traverse the hash backwards even after you have started forwards. If you feel that this is a useful feature, let me know and I will go ahead and add it.

Cheers - L~R

[djantzen]

Why can't you just store the value of the previous (or next, if applicable) entry in the HTML describing the button using a hidden field, or embedded in the href if done as a link? You're not trying to keep state in memory on the server between HTTP requests are you?