Facebook-登录重定向后如何保留app_data中的变量？

Question

With much thanks to other threads here I'm able to get variables passed to a facebook app tab page (With PHP sdk ) as such if the user is already logged in to facebook:

https://www.facebook.com/pages/my_dull_page/156000037732522?sk=app_305100762893495&app_data=choice%3Dmy_dull_choice

//check if logged in
// if not -> login -> redirect

$data= $facebook->getSignedRequest();
$app_data = $data['app_data'];

However if the user wasn't logged in, the variables are lost after the redirect, what would be the best way to pass them over?

Many thanks.

Answer 1

Use the php session.

session_start();

$_SESSION['variable'] = $value;

Then on the page after you redirect, you could check for the existence of the variable and set it, then destroy it.

session_start();
if( isset( $_SESSION['variable'] ) )
{
    $var = $_SESSION['variable'];
    unset( $_SESSION['variable'] );
}

The second way, and I am not sure how you are redirecting, is to pass the variables as GET vars in the redirect..

http://domain.com/redirect.php?var1=1&var2=2&var3=3

Then read the variables on the redirected page...

$var1 = isset( $_GET['var1'] ) ? $_GET['var1'] : NULL;