Last Domain Browsed through Cookie or Session Support

Make sure you set $cookie_domain = '.main.com' first. The rest is just JS or PHP code to set/read/react to the cookie value.

If you fail to set $cookie_domain, the sites cannot read a shared cookie for security reasons.

This should come close. The trick to to avoid an infinite redirect loop. You may also need to adjust the $time setting.

This code goes in a custom.module file and may be buggy.

function custom_init() {
  $_domain = domain_get_domain();
  $cookie = custom_get_my_cookie();

  // This part needs tweaking, it assumes the visitor has not been to the site
  // in the last 12 hours, therefore issue a redirect.
  $time = REQUEST_TIME - (12 * 60 * 60); // NOW, minus twelve hours.

  // If the cookie timestamp is longer than we like, then redirect to last
  // known domain. Note that this may not be the homepage, but will be the
  // current page request on the other domain.
  if (isset($cookie['custom_redirect']['time']) && $cookie['custom_redirect']['time'] < $time) {
    if ($domain = domain_machine_name_load($cookie['custom_redirect']['domain'])) {
      setrawcookie('custom_redirect', array());
      domain_goto($domain);
    }
  }
  // Now set the new cookie.
  $cookie = array(
    'domain' => $_domain['machine_name'],
    'time' => REQUEST_TIME,
  );
  setrawcookie('custom_redirect', $cookie);
}

function custom_get_my_cookie() {
  $cookie = isset($_COOKIE['custom_redirect']) ? $_COOKIE['custom_redirect'] : array();
  return $cookie;
}

You could also change the $time handling to be expire-based, but that likely won't work in your use case.

What _does_ it do? What, if anything is set in $_COOKIE?

I think this part is wrong:

// Now set me the new cookie. gimmie the cookie
  $cookie = array(
    'domain' => $_domain['machine_name'],
    'time' => REQUEST_TIME,
  );
  foreach($cookie as $key=>$value)
    {
    //setcookie($key, $value, null);
    setrawcookie('ubercookie_redirect', $value);
    }

You are trying to access an array above this. If the cookie cannot be an array, then each cookie needs a unique name.

What does this set:

// Now set me the new cookie. gimmie the cookie
  $cookie = array(
    'domain' => $_domain['machine_name'],
    'time' => REQUEST_TIME,
  );

    setrawcookie('ubercookie_redirect', $cookie);

Then we just have a string/array mismatch because I'm used to dealing with $_SESSION, which allows arrays.

<?php
function ubercookie_init() {
  $_domain = domain_get_domain();
  $cookie = ubercookie_get_my_cookie();

  $time = REQUEST_TIME + (12 * 60 * 60); //minus 12 hrs frm now <>><> why?? because

//tuma me to the last damn domain i was freaking on..
  if (!empty($cookie['ubercookie_redirect_time']) && $cookie['ubercookie_redirect_time'] < $time) {
    if ($domain = domain_machine_name_load($cookie['ubercookie_redirect_domain'])) {
      setrawcookie('ubercookie_redirect_time', '');
      domain_goto($domain);
    }
  }
  // Now set me the new cookie. gimmie the cookie
  $cookie = array(
    'domain' => $_domain['machine_name'],
    'time' => REQUEST_TIME,
  );
  foreach($cookie as $key=>$value)
    {
    //setcookie($key, $value, null);
    setrawcookie('ubercookie_redirect_' . $key, $value);
    }
  }
} 

/**
 * It may be easier to just read $_COOKIE[KEY] directly....
 */
function ubercookie_get_my_cookie() {
  $cookie = array(
    'ubercookie_redirect_time' => isset($_COOKIE['ubercookie_redirect_time']) ? $_COOKIE['ubercookie_redirect_time'] : '',
     'ubercookie_redirect_domain' => isset($_COOKIE['ubercookie_redirect_domain']) ? $_COOKIE['ubercookie_redirect_domain'] : '',
  );
  return $cookie;
}

It should work now. I just forgot that $COOKIE['this_cookie'] must be a string.

No. I mean that we tried to set $_COOKIE['ubercart_redirect'] = array('this', 'that');. You just can't do that, so we need two cookies, not one.

The redirect will only fire if your cookie is more than 12 hours old and your math is backwards ;-).

$time = REQUEST_TIME - (12 * 60 * 60); //minus 12 hrs frm now <>><> why?? because

You changed the code between comment 3 and comment 5.

NO minus means MORE than 12 hours old. $time here is a Unix timestamp, in seconds since 1970. Smaller values are in the past.

You want to force it to run, set it to 10 seconds and wait for an infinite loop:

$time = REQUEST_TIME - 10; // NOW minus 10 seconds.

Makes sense. But that's a programming issue outside my scope for support.

Feel free to post back when you finish working code.

Any update on this? or a working code?