Updated project files

Finished initial readme and added PHP files

README.md

@@ -9,22 +9,57 @@ This solution can be easily integrated with your existing PHP code that uses PHP
 
 2. Create a new MySQL database if you do not already have an existing one. Note down your MySQL credentials. Go to PHPMyAdmin or your database manager and run the following command:
 
-```mysql
-CREATE TABLE sessions
-(
-	id varchar(32) NOT NULL,
-	access int(10) unsigned,
-	data text,
-	PRIMARY KEY (id)
-);
-```
+	```mysql
+	CREATE TABLE sessions
+	(
+		id varchar(32) NOT NULL,
+		access int(10) unsigned,
+		data text,
+		PRIMARY KEY (id)
+	);
+	```
 
 3. Edit the file `database.class.php` and change the following variables to your existing database. 
-```php
-define("DB_HOST", "localhost");
-define("DB_USER", "yourusername");
-define("DB_PASS", "1234567890");
-define("DB_NAME", "yourdbname");
-```
-
-4. Make sure PHP has sufficient privileges and make sure that your MySQL server accepts connections if separate from your localhost.
+	```php
+	define("DB_HOST", "localhost");
+	define("DB_USER", "yourusername");
+	define("DB_PASS", "1234567890");
+	define("DB_NAME", "yourdbname");
+	```
+
+4. Make sure PHP has sufficient privileges and make sure that your MySQL server accepts connections if separate from your localhost.
+
+## Usage ##
+An example script called `example.php` has been provided for your convenience. This contains all the basic functionality you would need for storing, retrieving, and destroying a session. One thing to note is that you do not have to call `session_start()` on your code as that is already taken care of inside the `mysql.sessions.php` class.
+
+- **Declarations** (include these on the top of your PHP):
+	```php
+	include("database.class.php");	//Include MySQL database class
+	include("mysql.sessions.php");	//Include PHP MySQL sessions
+	$session = new Session();	//Start a new PHP MySQL session
+	```
+- **Storing in a session variable**:
+	```php
+	//Store variable as usual
+	$_SESSION['user'] = "johnsmith@example.com";
+	```
+- **Retrieving session variable**:
+	```php
+	//Show stored user
+	echo $_SESSION['user'];
+	```
+- **Unset and Destroy** (use these for signing out a user):
+	```php
+	//Clear session data (only data column)
+	session_unset();
+	//Destroy the entire session
+	session_destroy();
+	```
+## Troubleshooting ##
+If for some reason your code does not work, you can add the following lines to the top of your PHP script to show the errors:
+	```php
+	error_reporting(E_ALL);
+	ini_set('display_errors', '1');
+	```
+
+In addition, use PHPMyAdmin or your database manager to check your `sessions` table to see if the table has been altered in any way. For example, the table should populate as more session variables are being added.

database.class.php

@@ -0,0 +1,105 @@
+<?php
+
+	/*
+	Revised code by Dominick Lee
+	Original code derived from "Run your own PDO PHP class" by Philip Brown
+	Last Modified 2/27/2017
+	*/
+
+	// Define database configuration
+	define("DB_HOST", "localhost");
+	define("DB_USER", "yourusername");
+	define("DB_PASS", "1234567890");
+	define("DB_NAME", "yourdbname");
+
+	class Database{
+		private $host      = DB_HOST;
+		private $user      = DB_USER;
+		private $pass      = DB_PASS;
+		private $dbname    = DB_NAME;
+		private $dbh;
+		private $error;
+		private $stmt;
+
+		public function __construct(){
+			// Set DSN
+			$dsn = 'mysql:host=' . $this->host . ';dbname=' . $this->dbname;
+			// Set options
+			$options = array(
+				PDO::ATTR_PERSISTENT    => true,
+				PDO::ATTR_ERRMODE       => PDO::ERRMODE_EXCEPTION
+			);
+			// Create a new PDO instanace
+			try{
+				$this->dbh = new PDO($dsn, $this->user, $this->pass, $options);
+			}
+			// Catch any errors
+			catch(PDOException $e){
+				$this->error = $e->getMessage();
+			}
+		}
+
+		public function query($query){
+			$this->stmt = $this->dbh->prepare($query);
+		}
+		public function bind($param, $value, $type = null){
+			if (is_null($type)) {
+				switch (true) {
+					case is_int($value):
+						$type = PDO::PARAM_INT;
+						break;
+					case is_bool($value):
+						$type = PDO::PARAM_BOOL;
+						break;
+					case is_null($value):
+						$type = PDO::PARAM_NULL;
+						break;
+					default:
+						$type = PDO::PARAM_STR;
+				}
+			}
+			$this->stmt->bindValue($param, $value, $type);
+		}
+		public function execute(){
+			return $this->stmt->execute();
+		}    
+
+		public function resultset(){
+			$this->execute();
+			return $this->stmt->fetchAll(PDO::FETCH_ASSOC);
+		}
+
+		public function single(){
+			$this->execute();
+			return $this->stmt->fetch(PDO::FETCH_ASSOC);
+		}
+
+		public function rowCount(){
+			return $this->stmt->rowCount();
+		}
+
+		public function lastInsertId(){
+			return $this->dbh->lastInsertId();
+		}
+
+		public function beginTransaction(){
+			return $this->dbh->beginTransaction();
+		}
+
+		public function endTransaction(){
+			return $this->dbh->commit();
+		}
+
+		public function cancelTransaction(){
+			return $this->dbh->rollBack();
+		}
+
+		public function debugDumpParams(){
+			return $this->stmt->debugDumpParams();
+		}
+
+		public function close(){
+		  $this->dbh = null;
+		}
+	}
+?>

example.php

@@ -0,0 +1,28 @@
+<?php
+
+	//Written by Dominick Lee
+	//Last Modified 2/27/2017
+
+	//Enable the below two lines to show errors:
+	//error_reporting(E_ALL);
+	//ini_set('display_errors', '1');
+
+	include("database.class.php");	//Include MySQL database class
+	include("mysql.sessions.php");	//Include PHP MySQL sessions
+	$session = new Session();	//Start a new PHP MySQL session
+
+
+	//Store variable as usual
+	$_SESSION['user'] = "johnsmith@example.com";
+
+	//Show stored user
+	echo $_SESSION['user'];
+
+	//The following functions are used for sign-out:
+
+	//Clear session data (only data column)
+	//session_unset();
+
+	//Destroy the entire session
+	//session_destroy();
+?>

mysql.sessions.php

@@ -0,0 +1,132 @@
+<?php
+
+	/*
+	Revised code by Dominick Lee
+	Original code derived from "Essential PHP Security" by Chriss Shiflett
+	Last Modified 2/27/2017
+
+
+	CREATE TABLE sessions
+	(
+		id varchar(32) NOT NULL,
+		access int(10) unsigned,
+		data text,
+		PRIMARY KEY (id)
+	);
+
+	+--------+------------------+------+-----+---------+-------+
+	| Field  | Type             | Null | Key | Default | Extra |
+	+--------+------------------+------+-----+---------+-------+
+	| id     | varchar(32)      |      | PRI |         |       |
+	| access | int(10) unsigned | YES  |     | NULL    |       |
+	| data   | text             | YES  |     | NULL    |       |
+	+--------+------------------+------+-----+---------+-------+
+
+	*/
+
+
+class Session {
+	private $db;
+
+	public function __construct(){
+		// Instantiate new Database object
+		$this->db = new Database;
+
+		// Set handler to overide SESSION
+		session_set_save_handler(
+		array($this, "_open"),
+		array($this, "_close"),
+		array($this, "_read"),
+		array($this, "_write"),
+		array($this, "_destroy"),
+		array($this, "_gc")
+		);
+
+		// Start the session
+		session_start();
+	}
+	public function _open(){
+		// If successful
+		if($this->db){
+		// Return True
+		return true;
+		}
+		// Return False
+		return false;
+	}
+	public function _close(){
+		// Close the database connection
+		// If successful
+		if($this->db->close()){
+		// Return True
+		return true;
+		}
+		// Return False
+		return false;
+	}
+	public function _read($id){
+		// Set query
+		$this->db->query('SELECT data FROM sessions WHERE id = :id');
+		// Bind the Id
+		$this->db->bind(':id', $id);
+		// Attempt execution
+		// If successful
+		if($this->db->execute()){
+		// Save returned row
+		$row = $this->db->single();
+		// Return the data
+		return $row['data'];
+		}else{
+		// Return an empty string
+		return '';
+		}
+	}
+	public function _write($id, $data){
+		// Create time stamp
+		$access = time();
+		// Set query  
+		$this->db->query('REPLACE INTO sessions VALUES (:id, :access, :data)');
+		// Bind data
+		$this->db->bind(':id', $id);
+		$this->db->bind(':access', $access);  
+		$this->db->bind(':data', $data);
+		// Attempt Execution
+		// If successful
+		if($this->db->execute()){
+		// Return True
+		return true;
+		}
+		// Return False
+		return false;
+	}
+	public function _destroy($id){
+		// Set query
+		$this->db->query('DELETE FROM sessions WHERE id = :id');
+		// Bind data
+		$this->db->bind(':id', $id);
+		// Attempt execution
+		// If successful
+		if($this->db->execute()){
+		// Return True
+		return true;
+		}
+		// Return False
+		return false;
+	} 
+	public function _gc($max){
+		// Calculate what is to be deemed old
+		$old = time() - $max;
+		// Set query
+		$this->db->query('DELETE FROM sessions WHERE access < :old');
+		// Bind data
+		$this->db->bind(':old', $old);
+		// Attempt execution
+		if($this->db->execute()){
+		// Return True
+		return true;
+		}
+		// Return False
+		return false;
+	}
+}
+?>