Rating of images only once...

Sonic_Rage

Hey guys, I'm not finding the info I need so maybe someone can help me.

I have a very simple gallery that allows people to chose a rating on a image. I wish for them to only be able to rate it once. I did try making it so if they rated a picture, then a cookies was set and made the rate option vanish, problem is then it vanished for all of the other pics too. So bad idea.

How should I go about this? I was thinking that maybe I need to make some sort of table that records sessions, IP, and time? Maybe once you make a rating, it somehow checks to see if you rated that image already within a certain time frame using that same IP?

I'm kinda lost how to do this and if someone can give me some real world ideas or examples so I can try and build upon it would be greatly appreciated.

Thanks.

Shrike

Yep I agree that will be the best way to do it. IP addresses don't change in the time frames you are talking about. First create a database table

id - auto_increment primary key (not strictly necessary)
image_id - int - should relate to the id of the actual image reference in the database
user_ip - varchar (15)
user_access_time - datetime

Then when a user vists the page, check the table for various data

... assumes you are connected to a database ...
$imageid = something.gif //  This needs to be the current image being rated
$sql = "SELECT user_access_time FROM access_table WHERE '".$_SERVER['REMOTE_ADDR']."' AND image_id = '$image_id'";
$result = mysql_query($sql);
if($data = mysql_fetch_array($result)){
  // Ok we found a record, now check if time limit has passed
  if($data['user_access_time']+3600 < time()){ // User voted over an hour ago
    $sql = "DELETE FROM access_table WHERE user_ip = '".$_SERVER['REMOTE_ADDR']."' AND image_id = '$image_id";
    mysql_query($sql);
   addVote();
  }else{
    throw_error("Sorry, you already voted recently. Try again later");
}else{
  // No records were found, user is allowed to add a vote for this image
  addVote(); // Code which adds a vote to the database here
}

That's about all you need to do. You'd need to amend whatever function you use for adding votes in, so that it also adds a record into the new table.

Sorry for parse errors 🙂

Sonic_Rage

wow that's great! Thank you so much. I will work with that code and see if I can make it work for me, greatly appreciated!!! ^_

Shrike

I messed up a bit actually. If you store the date as a datetime type field, you'll need to convert it to do the evaluation. Alternatively just use a int (11) for the date, and then when writing the record use the time() function to add the time.

Sonic_Rage

lol actually I had already did that. After it first didn't work I realise I had to change it. It works great btw, thank you so much for your help on it.

Question... can I adapt that same code to possible work with only counting one hit per image view per hour or something like that? Right now, I discovered that they can pad the hits by refreshing the page. So can I do the same thing then with that?

Shrike

An easy way to avoid that is to do a header() redirect at the end.

Sonic_Rage

hmmm.... let me see then. I think I know what I did wrong, I made a code that everytime the page with the image gets hit, it registers a hit to that image, so I need to change that.