This tutorial presents a Class that can be used to store and to count the number of accesses of files.
It can be used especially to counts the number of downloads.
This class, named CountAccess connects to a MySQL database with the PHP mysqli extension. It has three methods and Constructor:
<?php
// - CountAccess class ( https://coursesweb.net )
// stores and counts the number of accesses
class CountAccess {
// define public properties for table name and its columns
public $tb_name = 'access';
public $tb_cols = array('urlf'=>'urlf', 'nrac'=>'nrac', 'dt'=>'dt');
// protected property to store the connection to the MySQL server
protected $conn;
// Constructor
public function __construct($server, $user, $pass, $db) {
// create the connection to MySQL database (stores it in $conn property)
$this->conn = new mysqli($server, $user, $pass, $db);
if (mysqli_connect_errno()) { printf("Connect failed: %s\n", mysqli_connect_error()); exit; }
// check if table $tb_name exists in $db
// if not exists, calls the setTable() method to create the table
$Tables_in_db = 'Tables_in_'.$db;
if($result=$this->conn->query("SHOW TABLES IN $db WHERE `$Tables_in_db` = '$this->tb_name'")) {
if(mysqli_num_rows($result)<=0) {
$this->setTable();
$result->close();
}
}
}
// method used to create the table
private function setTable() {
// sql query for CREATE TABLE
$sql = "CREATE TABLE `$this->tb_name` (
`". $this->tb_cols['urlf']. "` VARCHAR(88) PRIMARY KEY NOT NULL,
`". $this->tb_cols['nrac']. "` INT(8) UNSIGNED DEFAULT 1,
`". $this->tb_cols['dt']. "` TIMESTAMP
) CHARACTER SET utf8 COLLATE utf8_general_ci";
// performs the $sql query on the server to create the table, on failure returns the error
if (!$this->conn->query($sql) === TRUE) {
echo 'Error create table: '. $this->conn->error;
}
}
// method to insert / update the number of accesses of $urlf
public function setAccess($urlf) {
$urlf = $this->conn->real_escape_string($urlf); // escape special characters for use in the SQL query
// sql query for INSERT / UPDATE
$sql = "INSERT INTO `". $this->tb_name. "` (`". $this->tb_cols['urlf']. "`) VALUES ('$urlf') ON DUPLICATE KEY UPDATE `". $this->tb_cols['nrac']. "`=`". $this->tb_cols['nrac']. "`+1";
// performs the $sql query on the server to insert / update the values
if (!$this->conn->query($sql) === TRUE) {
echo 'Error: '. $this->conn->error;
}
}
// method to select the number of accesses (and the date-time of the last accessing) of $urlf
public function getAccess($urlf) {
$urlf = $this->conn->real_escape_string($urlf); // escape special characters for use in the SQL query
// sql query for SELECT
$sql = "SELECT `". $this->tb_cols['nrac']. "`, DATE_FORMAT(`". $this->tb_cols['dt']. "`, '%d-%m-%Y %H:%i') AS dt FROM `". $this->tb_name. "` WHERE `". $this->tb_cols['urlf']. "`='$urlf' LIMIT 1";
// perform the query and store the results
$result = $this->conn->query($sql);
// if the $result contains at least one row
if ($result->num_rows > 0) {
// store the number of accesses and the date-time in a array
while($row = $result->fetch_assoc()) {
$re = 'Accesses: '. $row['nrac']. ', last: <i>'. $row['dt']. '</i>';
}
}
else { $re = 'Accesses: 0, last: 0'; }
// closes the statement, to free the memory
$result->close();
return $re; // returns the string from $re
}
}
/* Using the CountAccess class */
// sets data for connecting to mysql database (server_address, username, password and database_name)
$server = 'localhost';
$user = 'username';
$pass = 'password';
$db = 'db_name';
// create the MySQL connection and a instance of CountAccess class
$objCA = new CountAccess($server, $user, $pass, $db);
// if there is $_GET['urlf']
if (isset($_GET['urlf'])) {
$urlf = trim(strip_tags($_GET['urlf'])); // delete tags and white spaces
// calls the setAccess() method to insert / update the number of accesses
$objCA->setAccess($urlf);
// Redirects the browser to the URL stored in $urlf
header("Location: " . $urlf); exit;
}
?>
<a href="path/class.CountAccess.php?urlf=dir/file_name.zip" title="Download title">Download</a>- "path/class.CountAccess.php" - is the path to the PHP file with the CountAccess class.
<?php
// include the file with CountAccess class
include('class.CountAccess.php');
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd" >
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Count Downloads</title>
</head>
<body>
<h3>Download</h3>
<!-- The Download links, via the class.CountAccess.php file -->
<a href="class.CountAccess.php?urlf=download/test.zip" title="Download test">Download Test</a> -
<?php echo $objCA->getAccess('download/test.zip'); ?>
<br />
<a href="class.CountAccess.php?urlf=Smile.zip" title="Download Smile">Download Smile</a> -
<?php echo $objCA->getAccess('Smile.zip'); ?>
</body>
</html>
This code will dislay something like:
<?php
// include the file with CountAccess class
include('class.CountAccess.php');
$name = 'a_string_value';
$objCA->setAccess($name); // insert / update the number of accesses for $name
echo $objCA->getAccess($name); // output the number of accesses and date-time
?>
<ul> <li>http://coursesweb.net/html/</li> <li>http://coursesweb.net/css/</li> </ul>
.some_class {
display: list-item;
}var obj = {
"courses": ["php", "javascript", "ajax"]
};
var jsonstr = JSON.stringify(obj);
alert(jsonstr); // {"courses":["php","javascript","ajax"]}$strhtml = '<body><div id="dv1">CoursesWeb.net</div></body>';
$dochtml = new DOMDocument();
$dochtml->loadHTML($strhtml);
$elm = $dochtml->getElementById("dv1");
echo $elm->nodeValue; // CoursesWeb.net