Voting Duplicate Votes - php

Question

We currently have a voting system setup that saves the IP address of the person making a vote to stop duplicate votes.
However everyday the IP address is removed from the database so they can re-vote on there favourite item.
Looking through the code below can you see how I can stop this so that a person with a certain IP address can never vote for that certain item again? They are however able to vote on the other entrants, but again only vote once.
Any ideas?
<?php
// Script Voting - http://www.coursesweb.net/
class Voting {
// properties
static protected $conn = false; // stores the connection to mysql
public $affected_rows = 0; // number of affected, or returned rows in SQL query
protected $voter = ''; // the user who vote, or its IP
protected $nrvot = 0; // if it is 1, the user can vote only one item in a day, 0 for multiple items
protected $svoting = 'mysql'; // 'mysql' to register data in database, any other value register in TXT files
public $votitems = 'voting'; // Table /or file_name to store items that are voted
public $votusers = 'votusers'; // Table /or filename that stores the users who voted in current day
protected $tdy; // will store the number of current day
public $eror = false; // to store and check for errors
// constructor
public function __construct() {
// sets $nrvot, $svoting, $voter, and $tdy properties
if(defined('NRVOT')) $this->nrvot = NRVOT;
if(defined('SVOTING')) $this->svoting = SVOTING;
if(defined('USRVOTE') && USRVOTE === 0) { if(defined('VOTER')) $this->voter = VOTER; }
else $this->voter = $_SERVER['REMOTE_ADDR'];
$this->tdy = date('j');
// if set to use TXT files, set the path and name of the files
if($this->svoting != 'mysql') {
$this->votitems = '../votingtxt/'.$this->votitems.'.txt';
$this->votusers = '../votingtxt/'.$this->votusers.'.txt';
}
}
// for connecting to mysql
protected function setConn() {
try {
// Connect and create the PDO object
self::$conn = new PDO("mysql:host=".DBHOST."; dbname=".DBNAME, DBUSER, DBPASS);
// Sets to handle the errors in the ERRMODE_EXCEPTION mode
self::$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
self::$conn->exec('SET CHARACTER SET utf8'); // Sets encoding UTF-8
}
catch(PDOException $e) {
$this->eror = 'Unable to connect to MySQL: '. $e->getMessage();
}
}
// Performs SQL queries
public function sqlExecute($sql) {
if(self::$conn===false OR self::$conn===NULL) $this->setConn(); // sets the connection to mysql
$re = true; // the value to be returned
// if there is a connection set ($conn property not false)
if(self::$conn !== false) {
// gets the first word in $sql, to determine whenb SELECT query
$ar_mode = explode(' ', trim($sql), 2);
$mode = strtolower($ar_mode[0]);
// performs the query and get returned data
try {
if($sqlprep = self::$conn->prepare($sql)) {
// execute query
if($sqlprep->execute()) {
// if $mode is 'select', gets the result_set to return
if($mode == 'select') {
$re = array();
// if fetch() returns at least one row (not false), adds the rows in $re for return
if(($row = $sqlprep->fetch(PDO::FETCH_ASSOC)) !== false){
do {
// check each column if it has numeric value, to convert it from "string"
foreach($row AS $k=>$v) {
if(is_numeric($v)) $row[$k] = $v + 0;
}
$re[] = $row;
}
while($row = $sqlprep->fetch(PDO::FETCH_ASSOC));
}
$this->affected_rows = count($re); // number of returned rows
}
}
else $this->eror = 'Cannot execute the sql query';
}
else {
$eror = self::$conn->errorInfo();
$this->eror = 'Error: '. $eror[2];
}
}
catch(PDOException $e) {
$this->eror = $e->getMessage();
}
}
// sets to return false in case of error
if($this->eror !== false) { echo $this->eror; $re = false; }
return $re;
}
// returns JSON string with item:['vote', 'nvotes', renot] for each element in $items array
public function getVoting($items, $vote = '') {
$votstdy = $this->votstdyCo($items); // gets from Cookie array with items voted by the user today
// if $vote not empty, perform to register the vote, $items contains one item to vote
if(!empty($vote)) {
// if $voter empty means user not loged
if($this->voter === '') return "alert('Vote Not registered.\\nYou must be logged in to can vote')";
else {
// gets array with items voted today from mysql, or txt-files (according to $svoting), and merge unique to $votstdy
if($this->svoting == 'mysql') {
$votstdy = array_unique(array_merge($votstdy, $this->votstdyDb()));
}
else {
$all_votstdy = $this->votstdyTxt(); // get 2 array: 'all'-rows voted today, 'day'-items by voter today
$votstdy = array_unique(array_merge($votstdy, $all_votstdy[$this->tdy]));
}
// if already voted, add in cookie, returns JSON from which JS alert message and will reload the page
// else, accesses the method to add the new vote, in mysql or TXT file
if(in_array($items[0], $votstdy) || ($this->nrvot === 1 && count($votstdy) > 0)) {
$votstdy[] = $items[0];
setcookie("votings", implode(',', array_unique($votstdy)), strtotime('tomorrow'));
return '{"'.$items[0].'":[0,0,3]}';
}
else if($this->svoting == 'mysql') $this->setVotDb($items, $vote, $votstdy); // add the new vote in mysql
else $this->setVotTxt($items, $vote, $all_votstdy); // add the new vote, and voter in TXT files
array_push($votstdy, $items[0]); // adds curent item as voted
}
}
// if $nrvot is 1, and $votstdy has item, set $setvoted=1 (user already voted today)
// else, user can vote multiple items, after Select is checked if already voted the existend $item
$setvoted = ($this->nrvot === 1 && count($votstdy) > 0) ? 1 : 0;
// get array with items and their votings from mysql or TXT file
$votitems = ($this->svoting == 'mysql') ? $this->getVotDb($items, $votstdy, $setvoted) : $this->getVotTxt($items, $votstdy, $setvoted);
return json_encode($votitems);
}
// insert /update rating item in #votitems, delete rows in $votusers which are not from today, insert $voter in $votusers
protected function setVotDb($items, $vote, $votstdy) {
$this->sqlExecute("INSERT INTO `$this->votitems` (`item`, `vote`) VALUES ('".$items[0]."', $vote) ON DUPLICATE KEY UPDATE `vote`=`vote`+$vote, `nvotes`=`nvotes`+1");
$this->sqlExecute("DELETE FROM `$this->votusers` WHERE `day`!=$this->tdy");
$this->sqlExecute("INSERT INTO `$this->votusers` (`day`, `voter`, `item`) VALUES ($this->tdy, '$this->voter', '".$items[0]."')");
// add curent voted item to the others today, and save them as string ',' in cookie (till the end of day)
$votstdy[] = $items[0];
setcookie("votings", implode(',', array_unique($votstdy)), strtotime('tomorrow'));
}
// select 'vote' and 'nvotes' of each element in $items, $votstdy stores items voted by the user today
// returns array with item:['vote', 'nvotes', renot] for each element in $items array
protected function getVotDb($items, $votstdy, $setvoted) {
$re = array_fill_keys($items, array(0,0,$setvoted)); // makes each value of $items as key with an array(0,0,0)
function addSlhs($elm){return "'".$elm."'";} // function to be used in array_map(), adds "'" to each $elm
$resql = $this->sqlExecute("SELECT * FROM `$this->votitems` WHERE `item` IN(".implode(',', array_map('addSlhs', $items)).")");
if($this->affected_rows > 0) {
for($i=0; $i<$this->affected_rows; $i++) {
$voted = in_array($resql[$i]['item'], $votstdy) ? $setvoted + 1 : $setvoted; // add 1 if the item was voted by the user today
$re[$resql[$i]['item']] = array($resql[$i]['vote'], $resql[$i]['nvotes'], $voted);
}
}
return $re;
}
// add /update rating item in TXT file, keep rows from today in $votusers, and add new row with $voter
protected function setVotTxt($items, $vote, $all_votstdy) {
// get the rows from file with items, if exists
if(file_exists($this->votitems)) {
$rows = file($this->votitems, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
$nrrows = count($rows);
// if exist rows registered, get array for each row, with - item^vote^nvotes
// if row with item, update it and stop, else, add the row at the end
if($nrrows > 0) {
for($i=0; $i<$nrrows; $i++) {
$row = explode('^', $rows[$i]);
if($row[0] == $items[0]) {
$rows[$i] = $items[0].'^'.($row[1] + $vote).'^'.($row[2] + 1);
$rowup = 1; break;
}
}
}
}
if(!isset($rowup)) $rows[] = $items[0].'^'.$vote.'^1';
file_put_contents($this->votitems, implode(PHP_EOL, $rows)); // save the items in file
// add row with curent item voted and the voter (today^voter^item), and save all the rows
$all_votstdy['all'][] = $this->tdy.'^'.$this->voter.'^'.$items[0];
file_put_contents($this->votusers, implode(PHP_EOL, $all_votstdy['all']));
// add curent voted item to the others today, and save them as string ',' in cookie (till the end of day)
$all_votstdy[$this->tdy][] = $items[0];
setcookie("votings", implode(',', array_unique($all_votstdy[$this->tdy])), strtotime('tomorrow'));
}
// get from TXT 'vote' and 'nvotes' of each element in $items, $votstdy stores items voted by the user today
// returns array with item:['vote', 'nvotes', renot] for each element in $items array
protected function getVotTxt($items, $votstdy, $setvoted) {
$re = array_fill_keys($items, array(0,0,$setvoted)); // makes each value of $items as key with an array(0,0,0)
if(file_exists($this->votitems)) {
$rows = file($this->votitems, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
$nrrows = count($rows);
// if exist rows registered, get array for each row, with - item^vote^nvotes
// if row with item is in $items, add its data in $re
if($nrrows > 0) {
for($i=0; $i<$nrrows; $i++) {
$row = explode('^', $rows[$i]);
$voted = in_array($row[0], $votstdy) ? $setvoted + 1 : $setvoted; // add 1 if the item was voted by the user today
if(in_array($row[0], $items)) $re[$row[0]] = array($row[1], $row[2], $voted);
}
}
}
return $re;
}
// gets and returns from Cookie an array with items voted by the user ($voter) today
protected function votstdyCo() {
$votstdy = array();
// if exists cookie 'votings', adds items voted today in $votstdy (array_filter() - removes null, empty elements)
if(isset($_COOKIE['votings'])) {
$votstdy = array_filter(explode(',', $_COOKIE['votings'])); // cookie stores string with: item1, item2, ...
}
return $votstdy;
}
// returns from mysql an array with items voted by the user today
protected function votstdyDb() {
$votstdy = array();
$resql = $this->sqlExecute("SELECT `item` FROM `$this->votusers` WHERE `day`=$this->tdy AND `voter`='$this->voter'");
if($this->affected_rows > 0) {
for($i=0; $i<$this->affected_rows; $i++) {
$votstdy[] = $resql[$i]['item'];
}
}
return $votstdy;
}
// returns from TXT file an array with 2 arrays: all rows voted today, and items voted by the user today
protected function votstdyTxt() {
$re['all'] = array(); $re[$this->tdy] = array();
if(file_exists($this->votusers)) {
$rows = file($this->votusers, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
$nrrows = count($rows);
// if exist rows registered, get array for each row, with - day^voter^item , compare 'day', and 'voter'
if($nrrows > 0) {
for($i=0; $i<$nrrows; $i++) {
$row = explode('^', $rows[$i]);
if($row[0] == $this->tdy) {
$re['all'][] = $rows[$i];
if($row[1] == $this->voter) $re[$this->tdy][] = $row[2];
}
}
}
}
return $re;
}
}

Answer 1

Make an SQL database of the IP addresses you want to ban, or if the list is short enough us an array.
Check if the IP address is in the database or array. If it's not allow them to vote. However, if it is let them think they voted put it in the database and make it as voted, but mark the vote as does not count so they will not try to get around your block.

Answer 2

This function seems to be deleting votes that are not from "today":
// insert /update rating item in #votitems, delete rows in $votusers which are not from today, insert $voter in $votusers
protected function setVotDb($items, $vote, $votstdy) {
$this->sqlExecute("INSERT INTO `$this->votitems` (`item`, `vote`) VALUES ('".$items[0]."', $vote) ON DUPLICATE KEY UPDATE `vote`=`vote`+$vote, `nvotes`=`nvotes`+1");
//$this->sqlExecute("DELETE FROM `$this->votusers` WHERE `day`!=$this->tdy");
$this->sqlExecute("INSERT INTO `$this->votusers` (`day`, `voter`, `item`) VALUES ($this->tdy, '$this->voter', '".$items[0]."')");
// add curent voted item to the others today, and save them as string ',' in cookie (till the end of day)
$votstdy[] = $items[0];
setcookie("votings", implode(',', array_unique($votstdy)), strtotime('tomorrow'));
}
I've commented out the delete query. You should test it out before putting it into production.

Answer 3

Your database structure seems a bit confusing, you have a table to count the vote per items and a table to count the vote per user.
You should review your database structure to merge those two tables in one table, with the : item, user, vote fields.
So you could keep a record for each vote of each user for each item as long as you want and eventualy make count() or sum() requests to get the total of votes per item