PHP编程：CI(Codeigniter)的Setting增强配置类实例

PHP编程
CREATE TABLE `system_settings` (
 `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
 `key` varchar(64) NOT NULL DEFAULT '',
 `value` mediumtext NOT NULL,
 `group` varchar(55) NOT NULL DEFAULT 'site',
 `autoload` enum('no','yes') NOT NULL DEFAULT 'yes',
 PRIMARY KEY (`id`,`key`),
 KEY `name` (`key`),
 KEY `autoload` (`autoload`)
) ENGINE=MyISAM AUTO_INCREMENT=11 DEFAULT CHARSET=utf8;

PHP编程
<?php
if (!defined('BASEPATH'))
  exit('No direct script access allowed');
class Setting {
  private $_ci;
  private $settings_autoloaded;
  private $settings = array();
  private $settings_group = array();
  private $settings_db;
  public function __construct() {
    $this->_ci = &get_instance();
    $this->settings_db = $this->_ci->config->item('settings_table');
    $this->autoload();
  }
  // ------------------------------------------------------------------------
  // 华丽的分割线 正式开始
  // ------------------------------------------------------------------------
  /**
   * 从数据库获取所有自动加载的设置
   */
  public function autoload() {
    //如果存在则直接返回
    if (!empty($this->settings)) {
      return $this->settings;
    }
    //如果系统不存在数据表则返回false
    if (!$this->_ci->db->table_exists($this->settings_db)) {
      return FALSE;
    }
    //查询标记为自动加载的项
    $this->_ci->db->select('key,value')->from($this->settings_db)->where('autoload', 'yes');
    $query = $this->_ci->db->get();
    if ($query->num_rows() == 0) {
      return FALSE;
    }
    //循环写入系统配置
    foreach ($query->result() as $k => $row) {
      $this->settings[$row->key] = $row->value;
      $this->_ci->config->set_item($row->key, $row->value);
    }
    //标记会话,避免重复读库
    //$this->_ci->session->set_userdata('settings_autoloaded', TRUE);
    return $this->settings;
  }
  // ------------------------------------------------------------------------
  /**
   * 获取单个设定
   *
   * <code>
   * <?php $this->settings->get('config_item');
   ?>
   * </code>
   */
  public function item($key) {
    if (!$key) {
      return FALSE;
    }
    //首先检查是否系统已经自动加载
    if (isset($this->settings[$key])) {
      return $this->settings[$key];
    }
    //查询数据库
    $this->_ci->db->select('value')->from($this->settings_db)->where('key', $key);
    $query = $this->_ci->db->get();
    if ($query->num_rows() > 0) {
      $row = $query->row();
      $this->settings[$key] = $row->value;
      return $row->value;
    }
    // 查询不到结果则查找系统config,返回值或者false
    return $this->_ci->config->item($key);
  }
  // ------------------------------------------------------------------------
  /**
   * 获取组配置
   */
  public function group($group = '') {
    if (!$group) {
      return FALSE;
    }
    $this->_ci->db->select('key,value')->from($this->settings_db)->where('group', $group);
    $query = $this->_ci->db->get();
    if ($query->num_rows() == 0) {
      return FALSE;
    }
    foreach ($query->result() as $k => $row) {
      $this->settings[$row->key] = $row->value;
      $arr[$row->key] = $row->value;
    }
    return $arr;
  }
  // ------------------------------------------------------------------------
  /**
   * 更改设置
   */
  public function edit($key, $value) {
    $this->_ci->db->where('key', $key);
    $this->_ci->db->update($this->settings_db, array('value' => $value));
    if ($this->_ci->db->affected_rows() == 0) {
      return FALSE;
    }
    return TRUE;
  }
  // ------------------------------------------------------------------------
  /**
   * 新增设置
   */
  public function insert($key, $value = '', $group = 'addon', $autoload = 'no') {
    // 检查是否已经被添加的设置
    $this->_ci->db->select('value')->from($this->settings_db)->where('key', $key);
    $query = $this->_ci->db->get();
    if ($query->num_rows() > 0) {
      return $this->edit($key, $value);
    }
    $data = array('key' => $key, 'value' => $value, 'group' => $group, 'autoload' => $autoload, );
    $this->_ci->db->insert($this->settings_db, $data);
    if ($this->_ci->db->affected_rows() == 0) {
      return FALSE;
    }
    return TRUE;
  }
  // ------------------------------------------------------------------------
  /**
   * 删除设置
   */
  public function delete($key) {
    $this->_ci->db->delete($this->settings_db, array('key' => $key));
    if ($this->_ci->db->affected_rows() == 0) {
      return FALSE;
    }
    return TRUE;
  }
  // ------------------------------------------------------------------------
  /**
   * 删除设置组及成员配置
   */
  public function delete_group($group) {
    $this->_ci->db->delete($this->settings_db, array('group' => $group));
    if ($this->_ci->db->affected_rows() == 0) {
      return FALSE;
    }
    return TRUE;
  }
}
/* End of file Setting.php */
/* Location: ./application/libraries/Setting.php */

PHP编程
/**
 * 系统配置表名
 */
$config['settings_table'] = "system_settings";