web applications - Solving the Double Submission Issue

Question

I would like to see how Web Developers avoid the double submission problem. So basically my understanding of the problem is as follows:

Double submission occurs when an impatient user submits a form multiple times, causing issues. This problem can be fixed by JavaScript (specifically jQuery scripts) that disable the submit button once the form has been submitted - a weakness of this is if clients have JavaScript disabled.

There is also server side methods of detection.

So my questions are:

How do people overcome double submission? What is a real life example of a problem caused by double submits? Do any Web Application Frameworks have double submission tools built in?

Answer 1

Real life situation: placing bets on a betting website. Users would double click and get two bets placed. Not good! Javascript checks were not sufficient to prevent this.

Solution:

1. Create UUID/GUID hidden input in form using server-side scripting language that renders the form.

2. On form submission immediately add this to a database table called UniqueSubmissions (for example). Then proceed with processing.

3. Every subsequent request with the same UUID/GUID will be rejected if found in the UniqueSubmissions table.

This worked for us. Hope that helps answer your question!