HTML forms and sessions

Namadoor

In most HTML forms, if you get an error, or need to correct something, you can just press the back button and all the fields will still be filled in except for and input=password fields.

That works with HTML forms, but when you put session_start() before a HTML form, when you press the back button, all the fields are erased. Is there a way to correct this?

KevinMG

yes and no.

if you hit the back button, i don't think there's any good way. it may be possible with some javascript, but that'd be a pain.

i'd suggest just displaying the error, and having a link back to the form page. then in all the < input value=..., just put something like this: < input value="<? echo $session_var; ?>" > that way as long as the varialbe is registered properly, it will fill in the values. if they haven't been registered yet, the field will stay blank.

hope that helps

mykg4orce

yep thats a good idea.

If its a large form, its gonna be a big pain to refill it, just cause u forgot to fill in one required field. So you should just register all non-password fields into the session. Even if the person closes the window, but when he/she returns to the page the session will fill in all field values.

Namadoor

OKay, I am not fimilar with cookies and such, but is there a way to start a session once, instead of on every page?

mykg4orce

NO, for every page that you want the session data available you MUST include session_start();

That basicaly tells the PHP script to look at all the information in the session corresponding to the session ID. And you can not add session_start(); to your header.php either 🙂

Namadoor

And if headers are sent before that, it will get warnings.

Namadoor

I wounder how these sites save the form inputs. If you press back, you will see that your posts are still there.

mykg4orce

keep in mind it also depends if the page gets reloaded when u hit 'back'

Because many times sites will say, "hit back to fill in all fields" etc But that only works if the page doesn't get reloaded and the data doesn't get lost.

I mean you could add a crude JavaScript:history.go(-1); but if the page was reloaded...then the data is lost.

So in the end, if you want to, use session_register(); to store all fields.

Namadoor

That is probley the best idea.

Namadoor

Okay, I have done that, now another question comes up.

Is there a way to make the reset button unregister all thoes? or will I have to turn the reset into a submit button which unregisters all value?

mykg4orce

yah you would have to call a reset action to the script like form.php?action=reset

and inside the file you would have:

if ($action == "reset") {
session_unregister('varname")
}
//display the form....