User Privileges

plasmahba

Hello

I have a question where I would like to read your opinion

Is simple

Let say I have a site with whatever number of different sections. Users will be able to access those sections with a Login and pwd.
What I want to do is to give different privileges to users to access whatever section, I mean : user 1 can access maybe to section A & B, user 2 B & C user 3 A & Z etc

I was thinking in create a logic combination of sections like
AB, AC, BA, BC etc but if I if I have 100 sections, combinations may come up to cubic 10. :-o and these section may grow or disappear depending the administrator criteria.

So how would you do it?

I want to use checkboxes to select the different sections a user can access to, but I'm still wondering how to tell my database to recognise which sections to display available for each user.

Any idea or recommendation is fully appreciated

thank you

drew010

this is where bitwise operations can come in handy...watch this.

<?php

define("BASIC", 1);
define("SECONDARY", 2);
define("MOD", 4);
define("ADMIN", 8);
define("SUPER", 16);
define("ROOT", 32);

$mylevel = BASIC | SECONDARY | MOD;
$beginner = BASIC;
$root = ROOT;

if ( ($beginner & ROOT) > 0) {
	echo "has root level permission.\n";
}

if ( ($mylevel & SECONDARY) > 0) {
	echo "has secondary level.\n";
}


echo "The value of the mylevel person is $mylevel.\n";
echo "The value of the beginner person is $beginner.\n";

?>

so in short, you set your permission levels in powers of two, each level twice as high as the next. to check if a user has permission in a certiain level, you bitwise and the value you want to check, and their total value.

If a person is going to have access to all levels, then their numeric level is the sum of all the levels together.

i know i didnt explain that the best, and you should be very comfortable with binary and bit arithmetic, so if you have questions just ask.

drew010

anyway, to comment a bit more on this. what you will probably want to do for your program, is have one table that stores those permission values, the 1,2,4,8.... part, and associate each one with a unique name. the user table should have a column that holds the numeric value of their level, (you can get this by bitwise or'ing all the levels you want them to have as i did in the script above) and on the pages you want to restict access to, you check what the level is required, then bitwise and with the permission level of the user.

plasmahba

Wow, I liked this answer,

Looks kind of "mathematical!" :-o

I have been looking for some "bitwise"info and I found this link. It is Very informative

http://www.litfuel.net/tutorials/bitwise.htm

Anyway i will make some tests to see if I have good results.

If I figure out another way to do it I will post it

thanks

drew010

yeah that is a good link, and is in php too. i found a bunch but they were in c.
it is a pretty straightforward thing once you use it. so if you run into any problems you know where to come.

Oh-Twadi_com

nice post good answer

topsub

my 2 cents is if u are using a database and want to set this up is to use linking tables, for ease of use and updating you will need to create you a little admin section to manage this but basic idea is to create a table with the "user id" and then the section of the page they can view.

then just pull from the database when you create the links for the user after they log in. Just need to know how to do table joins in sql

for every page that user can view you will have another record in the linking table, so yes it can get big depending on the amount of users and pages you have

just my 2 cents