Back Button Handle A Dynamic Form

Question

I have a form with an array of text fields. The user (through javascript) can add an arbitrary number of text fields to the form. After submitting the form and pressing th

Answer 1

How about creating an (with no name or outside the form so it's not submitted) in which you store an encoded list of extra fields to add and their values? While the browser won't remember newly-added fields on ‘back’, it will remember the values of hidden fields that were in the form from the start.

Here's an example that saves the extra fields on document unload and retrieves them on ready:

Notes:

• You can use form.onsubmit instead of window.onbeforeunload if you only need it to remember values over a submission. onunload doesn't work as some browsers will already have stored the old form values before that event occurs.

• In Firefox the position of the hidden input is important. For some reason, if you put it below the dynamically-added fields, Firefox gets confused about which input it is and fails to remember the value.

• This example doesn't work in Opera. It can be made to work in Opera, but it's a pain. Opera's calling of load and unload events is inconsistent so you have to use onsubmit instead, or setting the hidden field on a polling interval, or something. Worse, when Opera remembers previous form-field values, it actually doesn't fill them in until after onload has fired! This already causes many, many form-scripting problems. You can work around that by putting a small timeout in your onload to wait until the form values have gone in if you need Opera compatibility.