After submitting a form, i press reload and it submits again, how can i stop this?

pkipper

Hi guys,

The subject of this post might sound a bit confusing, I will see if I can explain my problem better.

I created a tagboard, which it loads the page with the messages on top, and below the messages there is a form. The user enters the name and the message in the form provided, press send and the message appears on top when the form is submitted.

The problem is, after the user submits the form, the new message appears, but if the user chooses to reload the page after submitting the form, the same message is sent again, so i end up with two identical messages. This can lead to people abusing the tagboard which i don't want it to happen. How can I stop this from happening?

vectorian798

I would say that when a message is posted, the form should check the DB to make sure the user did not just submit (post with a timestamp field also) or perhaps check if the user recently submitted something with the same subject (post with a timestamp field and check the subject). Perhaps the best way is to let the post run a script and then redirect the user to the forum page using the header() function. That way, a reload will simply reload the 'view forum' page, and not the script used to post.

Remember, that you cannot use header() on a page where there is already output to the browser. So, that script would have to do the posting without echoing anything to the screen and then use header to go back to the view forum page.

pkipper

Hiya,

I actually did something similar to what vectorian798 suggested, but i made it so it compares the values from the new message to the previous message entered, and if they are the same (same IP, same user and same comment), then the message is rejected. It works, but there is another problem. Since it compares every new message the user enters, what if that is the first message in the database (therefore there is no previous message)? I get an offset error of course. Right now I turned off error reporting :bemused: when i get to that particular error, but i am trying to figure out a proper method to fix this problem 🙁

sherry

You could use isset($var) e.g. if (isset($var)) or if (!isset($var)) depending on how you want to structure the routine.

Basically, the 1st array element $var[0] or whatever you want to be the 1st element, is undefined or if it is an associative array, the element $var['field'] is undefined. All it is asking is that it needs either to pre-defined (declared) or use isset() to get around that.

That's my guess.

herve

How do you store previous comments ?
In some database or in a flat file or ... ?

If in a database :

You run a query trying to look for previous same comment by
doing a :

SELECT * from comments where ip='$current_ip' AND
user='$current_user' AND comment='$current_comment'

there can be only two answers to this request :

1 answer : you know you can reject the new comment
because it's a duplicate
0 answer : either this is the first comment OR there's no
previous comment similar to the new one, either case you
can insert the new comment in the database.

Apply the same logic for a flat file .

sherry

Here is an interesting idea I found on a Perl forum:

http://www.perlmonks.com/index.pl?node_id=102826

Hope this helps. I think I'll use this suggestion for several of my applications. Thanks to that Perlmonk user.

envoy

Another solution would be to send the user to another page saying "Your message has been posted!" and redirect them to the main page after 5 seconds or so. Just like these forums 🙂

zapa

another solution would be to removed tollbars and menu bars. but i am sure that is to the last of your soultion list.

if you dont give user the button to refresh they want click it, but then you would have to disable left click too.