Disabling trans_sid: how to determine when sessions won't work

bunner_bob

I was concerned that visitors to our site were unable to shop due to disabled cookies (or whatever it is that would cause sessions not to work), so I enabled trans_sid.

Now I read that having this enabled can cause problems with search engines. I think this has to do with the first visit to the site resulting in the PHP session ID being written to a page's links, and only on subsequent loads (when it's determined that a cookie can be stored), will that session ID be removed from links. Search engines don't like session IDs in links, apparently.

I don't want to cause problems with search engines. I am happy to tell users they need to have cookies turned on if they want to shop. I'm just trying to figure out how to implement it.

I can see having a little check at the beginning of any account- or cart-related pages (that would require a login and/or session). Luckily, users can't add to the cart unless they're logged in (allows for storing the cart in the database).

Since I can't know what page users will be arriving FROM (they could even land directly on the "login" page), it seems I will have to seed a test cookie on every page, and on any pages with the cookie check I will have to do so AFTER the cookie "check" happens - otherwise the check will "see" the test cookie created on the same page load, and think everything is ok.

Hmm - this seems like a bit of a vicious circle - if the user arrives directly on any pages that do the cookie check, the cookie won't be there yet and so they'll be told they don't have cookies enabled.

How the heck do I go about this?

bunner_bob

As usual, once I started mucking around I found something that seemed to work.

As it turns out there are only five pages where the user is directed to log in (add_item, view_cart, checkout, my_account, and vendor_account). I employed what I found in this thread:
http://phpbuilder.com/board/showthread.php?t=10271705

To wit:

if (!isset($_GET['testcookie']) and !isset($_COOKIE['test']))
{
  setcookie("test", time(), time()+3600);
  header('location: '.$_SERVER['PHP_SELF'].'?testcookie=1');
}

if (isset($_COOKIE['test']))
{
  // show login form
}
else
{
  // show "turn on cookies" page 
}

It appears to be working - apparently that header-setting that refreshes the page is the secret.

Weedpacket

bunner_bob wrote:
add_item, view_cart, checkout, my_account, and vendor_account

If these are the only ones that get served up with a session ID in the url, then a question arises: which of these pages would a search engine need to index?

bunner_bob

Actually the session ID seems to get tacked on to most (but strangely not all) links in the site - for the first page in the site if cookies are enabled and trans_sid is on, and for all pages if cookies are off.

bunner_bob

Weedpacket wrote:
If these are the only ones that get served up with a session ID in the url, then a question arises: which of these pages would a search engine need to index?

I've been thinking about this. I would like to enable trans_sid functionality only where necessary. However, if I need to retain the session id no matter where in the site the user goes, I probably just need to have it "on" site-wide - right?

And I would have to session_start() on every page just to keep passing the session around - right?

Which means that, no matter what, visitors are going to get long URLs on the first page they hit. Which I worry about re. search engines.

Am I right?