Test if a link with specific text has been clicked (php)

Question

EDIT: is there a way to do this without reloading the page? I have a class that shows up when "Login" is pressed but it goes away quickly because the page is reloaded

I'm trying to test to see if a specific link text has been clicked because the same link can either have the texts "Login" or "Logout", but it's not registering that it's a valid link at all

index.php:

 <body>
        <nav>
            <ul>
                <li id="login">
                    <?php
                        if (isset($_SESSION['logged_user'])) 
                            echo "<a href='index.php?link=login'>Login";
                        else
                            echo "<a href='index.php?link=logout'>Logout";
                    ?>
                    </a>
                </li>

            </ul>
        </nav>

//LOGOUT
                if ($_GET['link']=='logout') {
                    unset($_SESSION["logged_user"] );
                    unset( $_SESSION );
                    $_SESSION = array();
                    session_destroy();
                }

error: Undefined index: link

Possible duplicate of [PHP: "Notice: Undefined variable", "Notice: Undefined index", and "Notice: Undefined offset"](http://stackoverflow.com/questions/4261133/php-notice-undefined-variable-notice-undefined-index-and-notice-undef) — user3942918, Mar 28 '17 at 21:54

score 1 · Accepted Answer · answered Mar 28 '17 at 03:50

1

Change this to

if ($_GET['link']=='logout') {

this

if (isset($_GET['link']) && $_GET['link']=='logout') {

answered Mar 28 '17 at 03:50

Sahil Gulati

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score 1 · Answer 2 · answered Mar 28 '17 at 03:57

When PHP page gets load, the PHP compiler checks for link property in GET array which is not there until you clicked on it. So you have to take care this condition with isset function so that it only validates when its available.

 if (isset($_GET['link']) && $_GET['link']=='logout')

Hope this helps!!

score 1 · Answer 3 · answered Mar 28 '17 at 04:05

I guess session_start(); is probably missing at the top to allow you to use $_SESSION['logged_user'];

  if(session_status() == PHP_SESSION_NONE){
        session_start();
    }

And also :

<?php
     if (isset($_GET['link']) && $_GET['link']=='logout') {
          unset($_SESSION["logged_user"] );
          unset( $_SESSION );
          $_SESSION = array();
          session_destroy();
         //  echo "Hello";
     }
    ?>

Good luck

Test if a link with specific text has been clicked (php)

3 Answers3