RE: [PHP-WIN] Preventing multiple submits

I agree. As a new user I couldn't follow or understand the class :( Maybe I will just accept the Javascript client side solution as it's only takes a few lines to disable the submit button once it's been pressed, whereas the PHP code to achieve the same kind of result seems to be rather complex (sessions, etc). I really wanted to keep everything server side though because then I could be 100% sure the user couldn't submit the form more than once. Thanks James -----Original Message----- From: Zak Greant [mailto:zak@php.net] Sent: 25 August 2000 16:41 To: Manuel Lemos Cc: Pablo Vera; jd@jamesduncan.co.uk; php-windows@lists.php.net Subject: Re: [PHP-WIN] Preventing multiple submits At 02:45 AM 8/25/00 -0300, Manuel Lemos wrote: >[snip] >The best solution for really preventing more that one submission of the >same form on the server side is to use create a unique key and pass it in >the form as hidden field. Store the key in a database (session data area >is ideal for this). When the first form submission is received, check if >the key exists in the database, delete it, accept the form. On further >submissions, check that the key does no longer exist and warn the user >that the form was already submitted. The user's session id will serve very nicely as the unique key. That is why I say that only a counter is needed. > >I know that JavaScript (or any other Client-Side tool) has its > >limitations as noted by you before, but with it you will stop the > >second submission before it is actually sent. The first script will > >run normally and return its output to the browser, without knowing > >that the user tried to send the form for a second time. The browser > >will no cancel that first connection, because it is not posting a > >second form. > >Right, you may want to check this PHP form generation and validation class. >It has an option to let you specify a text that is used to pop up a >confirmation box with Javascript that asks the user if he really means to >submit the form again. The user may confirm or cancel the form submission. > >This really works great since most of the times you just want to prevent >nervous users to submit forms more than once creating inadverted duplicate >database entries. > >http://phpclasses.UpperDesign.com/browse.html/package/1 The class is more mature and feature-rich than any other form generation/validation script that I have run across (or written for that matter :) - however, it might be a bit intimidating for a new user! I suppose that one thing to consider is that javascript is a nice clean way to stop most re-submissions. PHP can be used along with the js to ensure robust behavior. - zak