// Routing and dispatching

private static function dispatch(){

    // Instantiate the controller class and call its action method

    $controller_name = CONTROLLER . "Controller";

    $action_name = ACTION . "Action";

    $controller = new $controller_name;

    $controller->$action_name();

}

 <?php

 // Base Controller

 class Controller{

     // Base Controller has a property called $loader, it is an instance of Loader class(introduced later)

     protected $loader;

     public function __construct(){

         $this->loader = new Loader();

     }

     public function redirect($url,$message,$wait = 0){

         if ($wait == 0){

             header("Location:$url");

         } else {

             include CURR_VIEW_PATH . "message.html";

         }

         exit;

     }

 }

 基础控制器有一个变量$loader，它是Loader类的实例化（后面介绍）。准确的说，$this->loader是一个变量指向了被实例化的Load类。在这里我不过多的讨论，但是这的确是一个非常关键的概念。我遇到过一些PHP开发者相信在这个语句之后：

 $this->loader = new Loader();

 $this->load是一个对象。不，它只是一个引用。这是从Java中开始使用的，在Java之前，在C++和Objective C中被称为指针。引用是个封装的指针类型。比如，在iOS(O-C)中，我们创建了一个对象：

 UIButton *btn = [UIButton alloc] init];

 class Loader{

     // Load library classes

     public function library($lib){

         include LIB_PATH . "$lib.class.php";

     }

     // loader helper functions. Naming conversion is xxx_helper.php;

     public function helper($helper){

         include HELPER_PATH . "{$helper}_helper.php";

     }

 }

 <?php

 /**

 *================================================================

 *framework/database/Mysql.class.php

 *Database operation class

 *================================================================

 */

 class Mysql{

     protected $conn = false;  //DB connection resources

     protected $sql;           //sql statement

     /**

      * Constructor, to connect to database, select database and set charset

      * @param $config string configuration array

      */

     public function __construct($config = array()){

         $host = isset($config['host'])? $config['host'] : 'localhost';

         $user = isset($config['user'])? $config['user'] : 'root';

         $password = isset($config['password'])? $config['password'] : '';

         $dbname = isset($config['dbname'])? $config['dbname'] : '';

         $port = isset($config['port'])? $config['port'] : '3306';

         $charset = isset($config['charset'])? $config['charset'] : '3306';

         $this->conn = mysql_connect("$host:$port",$user,$password) or die('Database connection error');

         mysql_select_db($dbname) or die('Database selection error');

         $this->setChar($charset);

     }

     /**

      * Set charset

      * @access private

      * @param $charset string charset

      */

     private function setChar($charest){

         $sql = 'set names '.$charest;

         $this->query($sql);

     }

     /**

      * Execute SQL statement

      * @access public

      * @param $sql string SQL query statement

      * @return $result，if succeed, return resrouces; if fail return error message and exit

      */

     public function query($sql){        

         $this->sql = $sql;

         // Write SQL statement into log

         $str = $sql . "  [". date("Y-m-d H:i:s") ."]" . PHP_EOL;

         file_put_contents("log.txt", $str,FILE_APPEND);

         $result = mysql_query($this->sql,$this->conn);

         if (! $result) {

             die($this->errno().':'.$this->error().'<br />Error SQL statement is '.$this->sql.'<br />');

         }

         return $result;

     }

     /**

      * Get the first column of the first record

      * @access public

      * @param $sql string SQL query statement

      * @return return the value of this column

      */

     public function getOne($sql){

         $result = $this->query($sql);

         $row = mysql_fetch_row($result);

         if ($row) {

             return $row[0];

         } else {

             return false;

         }

     }

     /**

      * Get one record

      * @access public

      * @param $sql SQL query statement

      * @return array associative array

      */

     public function getRow($sql){

         if ($result = $this->query($sql)) {

             $row = mysql_fetch_assoc($result);

             return $row;

         } else {

             return false;

         }

     }

     /**

      * Get all records

      * @access public

      * @param $sql SQL query statement

      * @return $list an 2D array containing all result records

      */

     public function getAll($sql){

         $result = $this->query($sql);

         $list = array();

         while ($row = mysql_fetch_assoc($result)){

             $list[] = $row;

         }

         return $list;

     }

     /**

      * Get the value of a column

      * @access public

      * @param $sql string SQL query statement

      * @return $list array an array of the value of this column

      */

     public function getCol($sql){

         $result = $this->query($sql);

         $list = array();

         while ($row = mysql_fetch_row($result)) {

             $list[] = $row[0];

         }

         return $list;

     }

     /**

      * Get last insert id

      */

     public function getInsertId(){

         return mysql_insert_id($this->conn);

     }

     /**

      * Get error number

      * @access private

      * @return error number

      */

     public function errno(){

         return mysql_errno($this->conn);

     }

     /**

      * Get error message

      * @access private

      * @return error message

      */

     public function error(){

         return mysql_error($this->conn);

     }

 }
  

 <?php

 // framework/core/Model.class.php

 // Base Model Class

 class Model{

     protected $db; //database connection object

     protected $table; //table name

     protected $fields = array();  //fields list

     public function __construct($table){

         $dbconfig['host'] = $GLOBALS['config']['host'];

         $dbconfig['user'] = $GLOBALS['config']['user'];

         $dbconfig['password'] = $GLOBALS['config']['password'];

         $dbconfig['dbname'] = $GLOBALS['config']['dbname'];

         $dbconfig['port'] = $GLOBALS['config']['port'];

         $dbconfig['charset'] = $GLOBALS['config']['charset'];

         $this->db = new Mysql($dbconfig);

         $this->table = $GLOBALS['config']['prefix'] . $table;

         $this->getFields();

     }

     /**

      * Get the list of table fields

      *

      */

     private function getFields(){

         $sql = "DESC ". $this->table;

         $result = $this->db->getAll($sql);

         foreach ($result as $v) {

             $this->fields[] = $v['Field'];

             if ($v['Key'] == 'PRI') {

                 // If there is PK, save it in $pk

                 $pk = $v['Field'];

             }

         }

         // If there is PK, add it into fields list

         if (isset($pk)) {

             $this->fields['pk'] = $pk;

         }

     }

     /**

      * Insert records

      * @access public

      * @param $list array associative array

      * @return mixed If succeed return inserted record id, else return false

      */

     public function insert($list){

         $field_list = '';  //field list string

         $value_list = '';  //value list string

         foreach ($list as $k => $v) {

             if (in_array($k, $this->fields)) {

                 $field_list .= "`".$k."`" . ',';

                 $value_list .= "'".$v."'" . ',';

             }

         }

         // Trim the comma on the right

         $field_list = rtrim($field_list,',');

         $value_list = rtrim($value_list,',');

         // Construct sql statement

         $sql = "INSERT INTO `{$this->table}` ({$field_list}) VALUES ($value_list)";

         if ($this->db->query($sql)) {

             // Insert succeed, return the last record&rsquo;s id

             return $this->db->getInsertId();

             //return true;

         } else {

             // Insert fail, return false

             return false;

         }

     }

     /**

      * Update records

      * @access public

      * @param $list array associative array needs to be updated

      * @return mixed If succeed return the count of affected rows, else return false

      */

     public function update($list){

         $uplist = ''; //update fields

         $where = 0;   //update condition, default is 0

         foreach ($list as $k => $v) {

             if (in_array($k, $this->fields)) {

                 if ($k == $this->fields['pk']) {

                     // If it&rsquo;s PK, construct where condition

                     $where = "`$k`=$v";

                 } else {

                     // If not PK, construct update list

                     $uplist .= "`$k`='$v'".",";

                 }

             }

         }

         // Trim comma on the right of update list

         $uplist = rtrim($uplist,',');

         // Construct SQL statement

         $sql = "UPDATE `{$this->table}` SET {$uplist} WHERE {$where}";

         if ($this->db->query($sql)) {

             // If succeed, return the count of affected rows

             if ($rows = mysql_affected_rows()) {

                 // Has count of affected rows  

                 return $rows;

             } else {

                 // No count of affected rows, hence no update operation

                 return false;

             }    

         } else {

             // If fail, return false

             return false;

         }

     }

     /**

      * Delete records

      * @access public

      * @param $pk mixed could be an int or an array

      * @return mixed If succeed, return the count of deleted records, if fail, return false

      */

     public function delete($pk){

         $where = 0; //condition string

         //Check if $pk is a single value or array, and construct where condition accordingly

         if (is_array($pk)) {

             // array

             $where = "`{$this->fields['pk']}` in (".implode(',', $pk).")";

         } else {

             // single value

             $where = "`{$this->fields['pk']}`=$pk";

         }

         // Construct SQL statement

         $sql = "DELETE FROM `{$this->table}` WHERE $where";

         if ($this->db->query($sql)) {

             // If succeed, return the count of affected rows

             if ($rows = mysql_affected_rows()) {

                 // Has count of affected rows

                 return $rows;

             } else {

                 // No count of affected rows, hence no delete operation

                 return false;

             }        

         } else {

             // If fail, return false

             return false;

         }

     }

     /**

      * Get info based on PK

      * @param $pk int Primary Key

      * @return array an array of single record

      */

     public function selectByPk($pk){

         $sql = "select * from `{$this->table}` where `{$this->fields['pk']}`=$pk";

         return $this->db->getRow($sql);

     }

     /**

      * Get the count of all records

      *

      */

     public function total(){

         $sql = "select count(*) from {$this->table}";

         return $this->db->getOne($sql);

     }

     /**

      * Get info of pagination

      * @param $offset int offset value

      * @param $limit int number of records of each fetch

      * @param $where string where condition,default is empty

      */

     public function pageRows($offset, $limit,$where = ''){

         if (empty($where)){

             $sql = "select * from {$this->table} limit $offset, $limit";

         } else {

             $sql = "select * from {$this->table}  where $where limit $offset, $limit";

         }

         return $this->db->getAll($sql);

     }

 }
  

 <?php

 // application/models/UserModel.class.php

 class UserModel extends Model{

     public function getUsers(){

         $sql = "select * from $this->table";

         $users = $this->db->getAll($sql);

         return $users;

     }

 }

 <?php

 // application/controllers/admin/IndexController.class.php

 class IndexController extends BaseController{

     public function mainAction(){

         include CURR_VIEW_PATH . "main.html";

         // Load Captcha class

         $this->loader->library("Captcha");

         $captcha = new Captcha;

         $captcha->hello();

         $userModel = new UserModel("user");

         $users = $userModel->getUsers();

     }

     public function indexAction(){

                        $userModel = new UserModel("user");

         $users = $userModel->getUsers();

         // Load View template

         include  CURR_VIEW_PATH . "index.html";

     }

     public function menuAction(){

         include CURR_VIEW_PATH . "menu.html";

     }

     public function dragAction(){

         include CURR_VIEW_PATH . "drag.html";

     }

     public function topAction(){

         include CURR_VIEW_PATH . "top.html";

     }

 }