查找cookie并仅在php中重定向到页面一次

Question

I have this problem with redirecting to a page, I have a cookie "EmailSubscriber". so the condition here is if the website loads and finds that cookie then it will redirect to a particular page.

$rlink = get_option( "subscriber_redirect_link" );

if ( isset($_COOKIE["EmailSubscriber"]) ) {
    wp_redirect( $rlink, 302 );
}

but this code redirects every time I change pages, so I'm stuck on the redirected page, so how can I make this just once? meaning that when I open my browser and it detects the cookie "EmailSubscriber" then it will redirect me to a page and then when I navigate away from that page it won't redirect me again.

Answer 1

The reason for the continual redirect is that after the redirect the cookie is still set, and this code runs again. Cookies like session variables are persistent between requests.

You need to unset the cookie value before you redirect, also don't fetch the redirect link unless you are going to use it.

if (isset($_COOKIE['EmailSubscriber'])) {
    unset($_COOKIE['EmailSubscriber']);
    $rlink = get_option('subscriber_redirect_link');
    wp_redirect($rlink, 302);
}

That said, using a cookie to trigger a redirect is a rather odd design choice, perhaps you should instead flag the redirect using a get argument, for example:

https://example.com/script.php?redirect=1

if (isset($_GET['redirect'])) {
    $rlink = get_option('subscriber_redirect_link');
    wp_redirect($rlink, 302);
}

Or use a session variable as this will work even if the headers have already been sent, unlike using a cookie. It is also safer as the client can not alter the values in the session unlike a cookie.

if (isset($_SESSION['redirect'])) {
    unset($_SESSION['redirect']);
    $rlink = get_option('subscriber_redirect_link');
    wp_redirect($rlink, 302);      
}

Answer 2

You can use the combination of the cookie and session

first start the session (add this) in header.php, add this if the session_start() not declared previously

session_start();

then add this in your page which you want to redirect

$rlink = get_option( "subscriber_redirect_link" );

$_SESSION['previous'] = basename($_SERVER['PHP_SELF']);

//checking both values cookie and session
if ( isset($_COOKIE["EmailSubscriber"]) && isset($_SESSION["previous"])) {
    wp_redirect( $rlink, 302 ); //redirect if both set
}

then add this in footer.php

if (isset($_SESSION['previous'])) {
   if (basename($_SERVER['PHP_SELF']) != $_SESSION['previous']) {//this will compare your redirected page with the navigated page
        unset($_SESSION['previous']);//this will unset the session variable
   }
}

Answer 3

Give a value to the cookie TRUE or FALSE for example

TRUE - the redirect link is visited

FALSE - the redirect link is not visited

and on the redirect page change the value of the cookie.

Modify your code to:

if ( isset($_COOKIE["EmailSubscriber"]) ) {
    if($_COOKIE["EmailSubscriber"] == FALSE) {
        wp_redirect( $rlink, 302 );
    }
}

Then on the redirect page change the cookie value:

$_COOKIE["EmailSubscriber"] = TRUE;

When you will enter that site again it will not redirect anymore.