Here is an example of its useage…

$arr = array(
    array('lemon'),
    array('apple'),
    array('watermelon'),
    array('grape')
);

mdasort($arr, 0, SORT_DESC);

print_r($arr);

Will look like…

Array
(
    [0] => Array
        (
            [0] => watermelon
        )

    [1] => Array
        (
            [0] => lemon
        )

    [2] => Array
        (
            [0] => grape
        )

    [3] => Array
        (
            [0] => apple
        )

)

Download: Click here and extract the file to your Smarty "plugins/" folder.

<?php
/*
* Smarty plugin
* -------------------------------------------------------------
* Type: function
* Name: date_diff
* Version: 2.0
* Date: June 22, 2008
* Author: Matt DeKok
* Purpose: factor difference between two dates in days, weeks,
*          or years
* Input: date1 = "mm/dd/yyyy" or "yyyy/mm/dd" or "yyyy-mm-dd"
*        date2 = "mm/dd/yyyy" or "yyyy/mm/dd" or "yyyy-mm-dd" or $smarty.now
*        assign = name of variable to assign difference to
*        interval = "days" (default), "weeks", "years"
* Examples: {date_diff date1="5/12/2003" date2=$smarty.now interval="weeks"}
*           {date_diff date1="5/12/2003" date2="5/10/2008" assign="diff"}{$diff}
* -------------------------------------------------------------
*/
function smarty_function_date_diff($params, &$smarty)
{
    $date1 = mktime(0,0,0,1,1,2000);
    $date2 = mktime(0,0,0,date("m"),date("d"),date("Y"));
    $assign = null;
    $interval = "days";
    
    extract($params);

    $i = 1/60/60/24;
    if($interval == "weeks")
    {
        $i = $i/7;
    }
    elseif($interval == "years")
    {
        $i = $i/365.25;
    }
    
    $date1 = is_string($date1) ? strtotime($date1) : $date1;
    $date2 = is_string($date2) ? strtotime($date2) : $date2;
    
    if($assign != null)
    {
        $smarty->assign($assign,floor(($date2 - $date1)*$i));
    }
    else
    {
        return floor(($date2 - $date1)*$i);
    }
}
?>

class database
{
    public $db;                 //PDO Object
    
    const GET_RECORDSET = 0;
    const GET_RECORD = 1;
    const GET_VALUE = 2;
    
    function __construct($host, $username, $password, $database_name)
    {
        $dsn = "mysql:host=$host;dbname=$database_name";
        $options = array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION);
        try
        {
            @$db = new PDO($dsn, $username, $password, $options);
        }
        catch (PDOException $e)
        {
            $error = $e->getMessage();
            echo '<div class="error"><strong>PDO Error:</strong><br />' . $error . '</div>';
            exit;
        }
        $this->db = $db;
    }
    
    function query($sql_statement, $bind_values = array(), $return_type = self::GET_RECORDSET)
    {
        $query = $this->db->prepare($sql_statement);
        
        //bind dynamic values to the query string
        foreach($bind_values as $key => $value)
        {
            $dt = PDO::PARAM_STR;                               //value is a string
            if(is_int($value)) $dt = PDO::PARAM_INT;            //value is an integer
            elseif(is_bool($value)) $dt = PDO::PARAM_BOOL;      //value is a boolean
            $query->bindValue(":$key", $value, $dt);
        }
        
        //catch errors during execution and return an error message
        try
        {
            $result = $query->execute();
        }
        catch (PDOException $e)
        {
            $error = $e->getMessage();
            echo '<div class="error"><strong>SQL Error:</strong> <code>' . $sql_statement . '</code><br />' . $error . '</div>';
            return false;
        }
        
        try
        {
            if($return_type == self::GET_RECORDSET)     //returns a 2-dimensional array
            {
                $data = $query->fetchAll();
            }
            elseif($return_type == self::GET_RECORD)    //returns a 1-dimensional array
            {
                $data = $query->fetch();
            }
            else                                        //returns a value
            {
                $data = $query->fetchColumn();
            }
        }
        catch (PDOException $e)
        {
            if(is_bool($result))       // If the result is a boolean, return true/false
            {
                $data = $result;
            }
            else
            {
                $error = $e->getMessage();
                echo '<div class="error"><strong>PDO Error:</strong><br />' . $error . '</div>';
                exit;
            }
        }
        
        //Closes the cursor, enabling the statement to be executed again.
        $query->closeCursor();
        
        return $data;
    }
}

Calling the object is done like the following:

define('DB_HOST','localhost');
define('DB_USER','username');
define('DB_PASS','password');
define('DB_NAME','database name');
$dbase = new database(DB_HOST, DB_USER, DB_PASS, DB_NAME);

Executing a query that does not return data results in a true or false value. When inserting user input into the SQL string use the following method to prepare the variables so as to prevent SQL injection.

$values = array(
    'input1' => $_POST['input1'],
    'name' => $_POST['name']
);

$result = $dbase->query("INSERT INTO table (input1, name) VALUES(:input1, :name);", $values);

There are a few ways to return data. The first is a record set, which is returned into a mult-dimensional array. The first dimension is the record, and the second dimension is the fields of that record. This is the default. The next type is an individual record. It is returned into a single-dimensional array. The last type is a single value (no array).

// a record
$values = array('user_id' => $_SESSION['user_id']);
$user = $dbase->query("SELECT * FROM users WHERE user_id = :user_id;", $values, database::GET_RECORD);

// a value
$values = array('user_id' => $_SESSION['user_id']);
$user_level = $dbase->query("SELECT user_level FROM users WHERE user_id = :user_id;", $values, database::GET_VALUE);