在预订应用程序中保存房间

Question

I have some website for hotel reservation. People who are aligible, can choose a hotel, dates and capacity and pay for the order.

When the client make the decision and clicks the order button a few steps heppens:

1. Application check again for price and gathering order information

2. Saving rooms for the client to prevent overbooking

3. A timer set to 5 min for client order window (if time is gone the rooms are released)

If the client goes out the orger page a null_timer is trigered and saved rooms are released

If the client starts order (in order page) he can't procced other orders

• $_SESSION['order_iddle'] and timer changes triggered from client-side via ajax

JS trigger

window.onbeforeunload = function(){ 

      timer_null();   
      return ""; 

}

PHP check

if ((!isset($_SESSION['order_iddle'])) || (!$_SESSION['order_iddle']) )  {

     header('location: https://home-page/');

}

• $_SESSION['order_iddle'] updates with timer in php.
• timer_null() sends ajax request to php to update/check timer

Question 1:

This logic relies on onbeforeunload() function, but if the function not working in some browser we have trouble. If there a better way to trigger timer_null() when user go away from order page? Maybe in PHP?

Question 2:

When onbeforeunload() triggers and user clicks "Stay on the page", timer_null() triggered anyway. Is there something to do with that?

Thanks )

Answer 1

A better option would be to give the order an expiry value in your back end. This way you avoid triggering, problems when users don't use JS, problems when they stay on the page etc.

When they make an order set a value to the current time plus a number of minutes:

$order['expiry'] = time() + (5 * 60); // sets an expiry time for 5 minutes (5x60 seconds)

Then on a future page which checks whether the order is valid:

if (time() > $order['expiry']) {
     throw new Exception('This order is not valid');
}

Catch that exception and return it to the user however you'd like.

Suggestions for wider use

You might have other things in your use case which require, for example, stock to be held for those five minutes. However if you incorporate this expiry into your data store as well then it can be used to check expiries on any future orders.

If you wanted to not have to be checking thousands of potentially expired records each time a new order is made you could create a sort of "clean-up" script to run automatically. If you've not used crontab before I suggest your read up on it, but a script set to run at midnight every day with crontab:

0 0 * * * php /var/www/my-clean-up-script.php

Then in the script itself (pseudo-code):

$expired_orders = database_query ( GET orders FROM table WHERE expired_time < current_time)
for each $expired_orders
    database_query ( DELETE order)

Which should work for any queryable data store.