Question

I have a multipage form, with back buttons, and I’m trying to have a server-side way to maintain the form data if the user clicks back.

I have a back button like this:

<button id="backButton">Back</button>

And the button handler is as such:

$('#backButton').live('click',function() {
        window.history.back();
    });

After the first part of the form is submitted, I put all of the submitted data into $_SESSION variables. I can even echo out those variables on the second part of the form, but when I click the back button to go to the first part of the form, the session variables don’t carry over.

I am starting the session correctly and I use session variables for various other parts of the site, and they work flawlessly.

How can I carry variables back when a back button is pressed?

Answer 1

Sennheiser,
I can’t get a handle on your exact situation, but I can get your problem. Here are my thoughts:

1. When the user hits ‘back’, they usually load the page from the browser cache. Ergo, the browser is not asking PHP to re-parse the page with the session variables. Try hitting shift or Control F5 to re-request the page from the server.
2. #1 being successful or not is irrelevant, since no user is going to refresh the page thinking their results will return. You have to rely upon the browser OR JavaScript.
3. A brief review, looking this up, makes me think the following solutions are your best bet:

You can either..

• Use JavaScript to retrieve the form data and save the contents to a cookie, which will be loaded (Safely!! Look out for XSS..) whenever the form is loaded. You seem to use jQuery, that’ll help! I’m unsure of the safety, but read up on $.('#formID').serialize().

• Rely upon the browser’s native form-saving components. While doing a review of stack overflow, I found a similar question that had an answer that can help you. In summation, if your forms are automatically generated by JS or the page is non-cacheable (likely https, or your server says no-cache), you cannot rely upon the browser to save the form.

Let me know if my answers helped.