Displaying same page differently for users with different roles - php

Question

I wanted some suggestions from someone with experience in php.
I am making a website in php which will have 4 kinds of users :
1. guest(unregistered),
2. registered,
3. registered with special privilages,
4. admins
So the same page will be visible differently to all four of them.
Right now I am doing that by using if conditions.
In every page, I am checking the role of the user and then using many if statements to display the page accordingly.
It makes the code very big and untidy and I have to check conditions again and again in all the pages.
Is there a better way to do this?
How is this done in big professional websites?
Extended Question:
What is the most optimal way to do the same using a MVC framework like kohana 3.1? Does it have anything to do with acl?

Answer 1

It really depends on what you need.
For example if the page has big part that change completely, what I would suggest is to create different templates and include them depending on their "permissions"
$permission = $_SESSION['type_user'];
include '/path/to/file/with/permission/'.$permission.'/tpl.html';
and have something in the page similar to
<?php
//inside include.php you have the line similar to
//$permission = isset($_SESSION['type_user']) && $_SESSION['type_user']!=''?$_SESSION['type_user']:'common';
require_once '/mast/config/include.php';
include '/path/to/file/with/permission/common/header.html';
include '/path/to/file/with/permission/'.$permission.'/tpl_1.html';
include '/path/to/file/with/permission/common/tpl_2.html';
include '/path/to/file/with/permission/'.$permission.'/tpl_3.html';
include '/path/to/file/with/permission/common/footer.html';
?>
if the script is full of small parts like "show this text", or "show this button", you can create a function that will check the permissions for you
<?php
function can_user($action, $what){
switch($action){
case 'write':
return $your_current_if_on_what;
break;
case 'read':
default:
return $your_current_if_on_what;
break;
}
}
?>
and the template will look like:
[my html]
<?=can_user('read','button')?'My Button':''?>
[my html]
As a rule of thumb, if a piece of code is used more than 2 times, it needs to be put in a function/file separately, so if you have many "IFS" you need to create a function