Hey,

Has anyone ever had a problem with a page not being added to the back button history?

Here is my problem and page flow:

Page 1: User enters information in a form and submits it.

Page 2: INSERTS the information into the database and redirects to...

Page 3: Displays a printable view of the submitted info.

I need this process to be as fool-proof as possible so I am trying to guard against an accidental duplicate INSERT via page refresh or something.

The problem is -if the user happens to click the back button from Page 3, it goes directly to Page 1. This is bad because they could re-submit the same information again.

I had a catch for Page2 if the user re-entered it, but -since it's not in the back history - it won't stop the user.

Any clue why Page2 would be missed by the back button?

Its strictly a .php INSERT script and generates no HTML at all.

Thanks!

I am pretty sure that IE and Firefox ignore re-directs...

Can you be a little more specific about what type of re-direct?

Yeah, I just use:

[php]

echo "<meta http-equiv=Refresh content=2;url=page3.php>";

[/php]

But see, I get to Page 2 through a form submission, not a redirect.

That's why I'm a bit puzzled by this...

Or maybe I just don't fully understand it - probably that.

I know, but all that page two is, is a redirect.... so the browser just skips it and goes back to page one....

After all, even if you could go to page two you would just be sent on to page three....

So I better make sure it renders some type of HTML to officially make it a "page" right?

I don't know...

Is HTML... So I am at a loss as to the best way to handle this.
I think that you are going to need to handle all of this through your PHP code and not rely on a users history.

Actually, why do you have a "page 2" if it doesn't do anything but redirect. I think that the proper way to handle this is to combine page 2 and 3.

This is all I could find on Google, (not the best at answers) but it probably won't help...
http://www.thesitewizard.com/archive/phptutorial2.shtml
http://shiflett.org/articles/guru-speak-nov2004

Page 2 is an INSERT command into the database.

I had Page2 & 3 combined initially, but then I realized that an accidental refresh would cause a duplicate insert so that's when I split it up.

However, since I've been trying to work this out I may have be able to fix this going back to having 2 & 3 as one page.

Thanks for the links and advice.

I was thinking about how to handle this last night and it dawned on me that you could use a cookie (less secure) or a session (harder) to store whether the user had completed the form. You could also put the information they entered into the cookie or session so that the form could be auto-filled with their data. For example,

Page 1:
[php]<?php
if ( (!isset($_COOKIE['form_submited'])) || ($_COOKIE['form_submited'] != "yes")) {

//Show the form


} else {

// (1 )send them on to page three because they have already filled it out. The cookie says so!
header("Location: http://www.example.com/page3.php");

// (2) or you could just show the form again and populate it with the data they entered:

echo "Name: ". $_COOKIE['name'];
//etc?.

}
?>[/php]

Page 2:

After the data is put into the database create the cookie and put the value "yes" (the form has been sent)
[php]<?php
$result = mysql_query($sql);
if (!$result) { // if the data was not inserted
$value = "no";
} else { // the query was fine so lets set the value to "yes"
$value = "yes";
}
setcookie("form_submited", $value, time()+3600); /* expire in 1 hour */

header("Location: http://www.example.com/page3.php");

?>[/php]

Again you could also set a whole bunch of cookies for all of the data fields that were on your form so that if the user went back (say there was a DB error) the form would be auto filled in.

Thanks!

I had acutally come to a similar conclusion - though not quite as detailed as yours!

I was thinking of using a SESSION variable that got set once the INSERT took place and, if the user did happen to hit the back button, would just send them back to the home page.

Yours does cover more bases though.

Thanks for taking time - I'll will definatley put it to use!