Passing Session variables to javascript [duplicate]

This question already has answers here: How do I pass variables and data from PHP to JavaScript? (19 answers) Closed 8 years ago.

In an ExpressionEngine template, I'm setting a PHP session variable in a javascript file like this: (Yes, EE will parse the PHP and add plug the values to the javascript)

<?php session_start(); ?>  
function check_someone_else_result(data) {
  waiting_list_flag = false;
   <?php $_SESSION['waiting_list_flag'] = false;  ?>
  if(data.CanBuy=='YES'){
    show_for_someone_else();
  } else {
    waiting_list_flag = true;
   <?php $_SESSION['waiting_list_flag'] = true;  ?>
    $('#sm_content .oblcontent').html($('#waiting_list').html());
    $('#sm_content a.closebtn').click(function(){location.reload(true);});
    $('#sm_content a.yeswaitbtn').click(function(){show_for_someone_else();});
  } // if(data.CanBuy=='YES')
} // function check_someone_else_result

Now, in the show_for_someone_else() function, I'm redirecting to another page that loads another javascript file and I'm try开发者_如何学Cing to set a javascript variable to the same value that I set the session variable to above.

<?php session_start(); ?>
   var CART_URL          = '{site_url}store/checkout/cart/';
   $(document).ready(function(){
     // attach the validationEngine to the form
     $("#voucher_form").validationEngine('attach', {
                      scroll: false
     }); // $("#voucher_form").validationEngine

     // handles the NExt button click
     $('#checkout-step-billing a').click(function(){
      $('#checkout-step-billing .voucher_form').submit();
     }); // $('#checkout-step-billing a').click

     // handles keypresses in all the fields in the form to submit the 
     // form when the press enter
     $("#checkout-step-billing .voucher_form input").keypress(function (e) {
      if ((e.which && e.which == 13) || (e.keyCode && e.keyCode == 13)) {
        $('#checkout-step-billing .voucher_form').submit();
        return false;
      } else {
        return true;
      }
     }); // $("#checkout-step-billing .voucher_form input").keypress

     // set the wait_list_flag from the session variable
     var wait_list_flag = <?php $_SESSION['waiting_list_flag']; ?>   
   }); // $(document).ready

But I am not getting anything at all.

How do I need to do this?

---

 var wait_list_flag = <?php $_SESSION['waiting_list_flag']; ?>   

should be

 var wait_list_flag = <?php echo $_SESSION['waiting_list_flag']; ?>;
                            ^^^^                                   ^

Without the echo, the PHP block doesn't output anything, so nothing gets inserted into the Javascript block. You're also missing the trailing semicolon in the javascript, which may also cause a fatal parse error.

---

To set the value, you will need to echo / print the $_SESSION['waiting_list_flag']; in the second snippet.

Keep in mind, in the first snippet, PHP will be run first (it's not run with the JavaScript), so the session var will always be true. (Unless that is what you meant wrt EE)