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
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');
    $this->autoload();
  }
  // ------------------------------------------------------------------------
  // 華麗的分割線 正式開始
  // ------------------------------------------------------------------------
  /**
   * 從數(shù)據庫獲取所有自動加載的設置
   */
  public function autoload() {
    //如果存在則直接返回
    if (!empty($this->settings)) {
      return $this->settings;
    }
    //如果系統(tǒng)不存在數(shù)據表則返回false
    if (!$this->_ci->db->table_exists($this->settings_db)) {
      return FALSE;
    }
    //查詢標記為自動加載的項
    $this->_ci->db->select('key,value')->from($this->settings_db)->where('autoload', 'yes');
    $query = $this->_ci->db->get();
    if ($query->num_rows() == 0) {
      return FALSE;
    }
    //循環(huán)寫入系統(tǒng)配置
    foreach ($query->result() as $k => $row) {
      $this->settings[$row->key] = $row->value;
      $this->_ci->config->set_item($row->key, $row->value);
    }
    //標記會話，避免重復讀庫
    //$this->_ci->session->set_userdata('settings_autoloaded', TRUE);
    return $this->settings;
  }
  // ------------------------------------------------------------------------
  /**
   * 獲取單個設定
   *
   * <code>
   * <?php $this->settings->get('config_item');
   ?>
   * </code>
   */
  public function item($key) {
    if (!$key) {
      return FALSE;
    }
    //首先檢查是否系統(tǒng)已經自動加載
    if (isset($this->settings[$key])) {
      return $this->settings[$key];
    }
    //查詢數(shù)據庫
    $this->_ci->db->select('value')->from($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;
    }
    // 查詢不到結果則查找系統(tǒng)config，返回值或者false
    return $this->_ci->config->item($key);
  }
  // ------------------------------------------------------------------------
  /**
   * 獲取組配置
   */
  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 $arr;
  }
  // ------------------------------------------------------------------------
  /**
   * 更改設置
   */
  public function edit($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;
  }
  // ------------------------------------------------------------------------
  /**
   * 新增設置
   */
  public function insert($key, $value = '', $group = 'addon', $autoload = 'no') {
    // 檢查是否已經被添加的設置
    $this->_ci->db->select('value')->from($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;
  }
  // ------------------------------------------------------------------------
  /**
   * 刪除設置
   */
  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;
  }
  // ------------------------------------------------------------------------
  /**
   * 刪除設置組及成員配置
   */
  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 */

/**
 * 系統(tǒng)配置表名
 */
$config['settings_table'] = "system_settings";