toutpratique/modules/cmsps/ajax_voting.php

<?php
require_once '../../config/config.inc.php';
require_once '../../init.php';
require_once dirname(__FILE__).'/classes/CmsPsPost.php';

$id_article = Tools::getValue('id_post');
$cms_post = new CmsPsPost($id_article);
$result = array();

if (Validate::isLoadedObject($cms_post)) {
 	$result['errors'] = false;
 	if (!checkCookie($cms_post->id)) {
 		$cms_post->note = $cms_post->note + 1;
 		$cms_post->save();
 		$result['nb_vote'] = $cms_post->note;
 		$result['already_vote'] = false;
 	} else {
 		$result['nb_vote'] = $cms_post->note;
 		$result['already_vote'] = true;
 	}
	die(Tools::jsonEncode($result));
} else {
	$result['errors'] = true;
	die(Tools::jsonEncode($result));
}

function checkCookie($id_post) {
	if (isset($_COOKIE['voting'])) {
		$cookie = utf8_decode($_COOKIE['voting']);

		if ($cookie != 0) {
			$already_vote = explode(',', $cookie);
			if (in_array($id_post, $already_vote)) {
				return true;
			} else {
				$vote = '';
				for ($i=0; $i < (sizeof($already_vote)-1) ; $i++) { 
					$vote.= $already_vote[$i].',';
				}
				$vote.=$id_post.',';
				setcookie("voting", utf8_encode($vote), time()+(60*60*24*300), '/');
				return false;
			}
		} else {
			$vote = $id_post.',';
			setcookie("voting", utf8_encode($vote), time()+(60*60*24*300), '/');
			return false;
		}
	} else {
		setcookie("voting", utf8_encode('0'), time()+(60*60*24*300), '/');
		return false;
	}
}