Codeigniter Setting 增强配置类 - 可以用于自动读取数据库内容

该增强配置类适用配置项要求比较灵活的项目。可实现预加载配置、组配置、单项调取、增、删、改配置，无需在改动config文档。

使用：

在需要的地方

$this->load->library('setting');

对于预加载项可以使用$this->config->item();进行获取

对于临时调取项可以使用$this->setting->item(); 进行获取

首先，创建数据表

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;

然后，在application/libraries目录下创建setting.php，内容如下

<?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 */

最后，打开application/config/config.php，新增

/**

 * 系统配置表名

 */



$config['settings_table'] = "system_settings";