Why can't I unset($_POST)

[suttercain]

Hello everyone,

 

I have a small script I wrote so people can vote on a page:

 

<?php
//voting system
		  function voted() {
		  echo "Thank you for voting!"; }
		  $voting = "SELECT * FROM comicvote WHERE comic_id ='" . $row['comic_id'] . "'";
		  $votes = mysql_query($voting) or die (mysql_error());
		  $sum = 0;
		  while ($rowvote = mysql_fetch_row($votes)) {
		  $sum += $rowvote['0'];
		  } 
		  $average = $sum/5 *100;
		  $format = number_format($average,2);
		  if ($votes == !NULL) { 		
		  		if ($average >= 1 && $average <= 59.99) {
					$rating = "<img src='../images/comics/grade_f.gif'>";
				} elseif ($average==0) {
					$rating = "Be The First To Vote!<br>";
				} elseif ($average >= 60.00 && $average <= 69.99) {
					$rating = "<img src='../images/comics/grade_d.gif'>";
				} elseif ($average >= 70.00 && $average <= 79.99) {
					$rating = "<img src='../images/comics/grade_c.gif'>";
				} elseif ($average >= 80.00 && $average <= 89.99) {
					$rating = "<img src='../images/comics/grade_b.gif'>";
				} else {
					$rating = "<img src='../images/comics/grade_a.gif'>"; }
			echo $rating;
		  } 
		  $total = mysql_num_rows($votes);
		  if ($total > 0) {
		  	echo "<br>Based on $total votes!"; }
		  if ($vbulletin->userinfo['usergroupid'] == '6' || 
		  	  $vbulletin->userinfo['usergroupid'] == '2') {
			  if (!isset($_POST['submit'])) { 
			  	voteNow();
		  		} else {
				$rating = $_POST['rating'];
				$comic_id = $row['comic_id'];
				$sent = mysql_query ("INSERT INTO comicvote (rating, comic_id) VALUES ('$rating', '$comic_id')") or die(mysql_error());
                                        unset($_POST['submit']);//Trying to unset the $_POST, not working though!
				voted ();
		  		}
			} else {
			echo "<a href='/forums/register.php?s='><br>Login to Vote</a>";
				}
		  
		  
		  function voteNow() {
		  ?>
		  	<form action="<?php $_SERVER['PHP_SELF'] ?>" method="post">
			     <div align="center">
				  <select name="rating">
			 	     <option value="5">A</option>
				     <option value="4">B</option>
				     <option value="3">C</option>
				     <option value="2">D</option>
				     <option value="1">F</option>
			       </select>
		  		  <input type="submit" name="submit" value="Vote">
				   </div>
		  	</form>
		  <?php 
		  } 
		  ?>

 

The issue I am having is that after the vote in inserted into the MySQL database I want the $_POST['submit'] to be unset or destroyed. This isn't working, because each time the page is reloaded it votes again and again.

 

Anyone have any suggestions? Thanks.

 

SC

[benjaminbeazy]

redirect the page after it is done processing, else the client will continue to send post headers

[suttercain]

What if I need the page to be directed to itself? I need it so the user never leaves that page.

[benjaminbeazy]

doesnt matter, just redirect it to itself

[yzerman]

instead of unsetting $_POST['submit']

 

before this line:

  echo "Thank you for voting!"; }

 

add

$submitted = $_POST['submit'];

if ($submitted == $_POST['submit']) {

//do the query and echo the results

$submitted = NULL;

} //close this if statement

 

then change

if (!isset($_POST['submit'])) {

 

to

if ($submitted != $_POST['submit']) {

 

That should work - maybe

[suttercain]

I tried running this, but of course got that the headers have already been sent:
[code]
<?php
if (!isset($_POST['submit'])) { 
			  	voteNow();
		  		} else {
				$rating = $_POST['rating'];
				$comic_id = $row['comic_id'];
				$sent = mysql_query ("INSERT INTO comicvote (rating, comic_id) VALUES ('$rating', '$comic_id')") or die(mysql_error());
				unset($_POST['submit']);
				voted ();
				header("comicvote.php");
		  		}
?>

 

ERROR:

Warning: Cannot modify header information - headers already sent by (output started at /home/superman/public_html/comics/view_comics1.php:13) in /home/superman/public_html/comics/comicvote.php on line 41

 

Other than using

<form action="<?php $_SERVER['PHP_SELF'] ?>" method="post">

I am not sure how to do this.[/code]

[yzerman]

if your going to do a redirect, use javascript and not a header

 

just change that line to this:

 

echo "<br />Redirecting...<script language='javascript'>setTimeout('window.location=\"./comicvote.php\"',2000);</script>";

[mmarif4u]

Or just simply put this at very top of the page to resolve the header sent problem.

 

<?php
ob_start();
?>

[suttercain]

Hi yzerman,

 

Thanks for the suggestions. I tried both,

 

nstead of unsetting $_POST['submit']

before this line:
  echo "Thank you for voting!"; }

add
$submitted = $_POST['submit'];
if ($submitted == $_POST['submit']) {
//do the query and echo the results
$submitted = NULL;
} //close this if statement

then change
if (!isset($_POST['submit'])) {

to
if ($submitted != $_POST['submit']) {

 

and also using the javascript.

 

I am still having the same issue. I hit reload, it counts the vote over and over.

[suttercain]

Hi mmarif4u

 

I tried the ob_start, still got the header errors. Thank you for the suggestion.

 

 

[yzerman]

because when you hit refresh, you (the client) are resending the form. The only way around this is to redirect to another page.

 

Now because this is a voting system, I imagine you are inputting a vote only for registered users. What you can do in that case, is add a field to your table if it doesn't exist and store the username. Then check for a vote on that particular subject from that username.

 

If you are not requiring registered users, store the ip of the user with the vote - then before it is submitted, check the table for that IP address submitting a vote, and stop the query if that IP has already submitted a vote for that particular subject.

[suttercain]

Hi yzerman,

 

Yeah I had already started that and added a column to my MySQL table for the user id. I think I may go that route also, cause that means they can't come back another day and revote.

 

I thank all three of you for helping me out. I'll try the user one time vote thing.

 

Thanks for your time.

 

SC

[mmarif4u]

I am agree with  yzerman suggestion.

This is right here to avoid all these non stuff.

[homer.favenir]

<form action="<?php $_SERVER['PHP_SELF'] ?>" method="post">

you're missing echo

<form action="<?php echo $_SERVER['PHP_SELF'] ?>" method="post">