登录前后如何分离应用程序逻辑？

Question

Here is the idea.... ...I have a index.php.... ... The application is have one page only, just like the facebook wall, if the user is logined, they can see their "wall", but if they are not logined, they see a register page.... ....

Should I put all these login in the index.php? or I need to separate two index.php...one is logined_index.php, and notLogined_index.php??

Moreover, how can I prevent someone who is not logined in the index.php? Thank you.

Answer 1

If your application will remain small there is no need for a separate file. You can use something like this:

<?php
    session_start();
    if (!isset($_SESSION['uid']) | $_SESSION['uid']=='') $_SESSION['uid']=0;

    if($_SESSION['uid']!=0) {
        if (/* user logs out */) {
            session_destroy();
            /* show register/login form */
        }
        else {
            /* main page code goes here */
        }
    }
    else {
        if (/* register details entered */) {
            if (/* register details valid */) {
                /* register the user and display it all went successful */
            }
            else {
                /* wrong register info - display error */
            }
        }
        else if (/* login details enetered */) {
                if (/* user exists and login correct */) {
                $_SESSION['uid'] = /* set the id of the logged user */;
                /* log user in and redirect to main page */
            }
                        else {
                /* wrong login info - display error */
            }
        }
        else {
            /* show register/login form */
        }
    }
?>

This is just a simple code layout to build on.