Question

我想用一些函数扩展/system/core/Log.php库。一个函数应该通过自定义函数sendMail()发送错误，该函数是Custom_library.php的一部分。

因此，我创建了文件/application/core/MY_Log.php

class MY_Log extends CI_Log {
  public function __construct()
  {
    parent::__construct();
  }

  public function write_log($level, $msg)
  {
    $result = parent::write_log($level, $msg);

    return $result;
  }
}

问题：我无法加载Custom_library.php。这些方法都不起作用：

//approach 1    
$this->load->library('Custom_library');

//approach 2  
$CI =& get_instance();
$CI->load->library('Custom_library');

方法2的错误消息：

Fatal error: Uncaught Error: Class 'CI_Controller' not found in /home/gp/public_html/system/core/CodeIgniter.php:366 Stack trace: #0 /home/gp/public_html/application/core/MY_Log.php(13): get_instance() #1 /home/gp/public_html/system/core/Common.php(478): MY_Log->write_log('error', 'Severity: error...') #2 /home/gp/public_html/system/core/Exceptions.php(105): log_message('error', 'Severity: error...') #3 /home/gp/public_html/system/core/Common.php(662): CI_Exceptions->log_exception('error', 'Exception: Clas...', '/home/gp/public...', 366) #4 [internal function]: _exception_handler(Object(Error)) #5 {main} thrown in /home/gp/public_html/system/core/CodeIgniter.php on line 366

问题：是否可以在核心类中加载和使用库？

更新

我通过函数&load_class尝试了这种方法。

function &load_class($class, $directory = 'libraries', $param = NULL)
    {
        static $_classes = array();

        // Does the class exist? If so, we're done...
        if (isset($_classes[$class]))
        {
            return $_classes[$class];
        }

        $name = FALSE;

        // Look for the class first in the local application/libraries folder
        // then in the native system/libraries folder
        foreach (array(APPPATH, BASEPATH) as $path)
        {
            if (file_exists($path.$directory.'/'.$class.'.php'))
            {
                $name = 'CI_'.$class;

                if (class_exists($name, FALSE) === FALSE)
                {
                    require_once($path.$directory.'/'.$class.'.php');
                }

                break;
            }
        }

        // Is the request a class extension? If so we load it too
        if (file_exists(APPPATH.$directory.'/'.config_item('subclass_prefix').$class.'.php'))
        {
            $name = config_item('subclass_prefix').$class;

            if (class_exists($name, FALSE) === FALSE)
            {
                require_once(APPPATH.$directory.'/'.$name.'.php');
            }
        }

        // Did we find the class?
        if ($name === FALSE)
        {
            // Note: We use exit() rather than show_error() in order to avoid a
            // self-referencing loop with the Exceptions class
            set_status_header(503);
            echo 'Unable to locate the specified class: '.$class.'.php';
            exit(5); // EXIT_UNK_CLASS
        }

        // Keep track of what we just loaded
        is_loaded($class);

        $_classes[$class] = isset($param)
            ? new $name($param)
            : new $name();
        return $_classes[$class];
    }

如果我运行函数$CI =& load_class('Custom_library');，它会找到正确的文件，而不是寻找带有前缀＆＃34; CI _＆＃34;的类。抛出错误信息：

Fatal error: Uncaught Error: Class 'CI_Custom_library' not found in /home/gp/public_html/system/core/Common.php:196 Stack trace: #0 /home/gp/public_html/application/core/MY_Log.php(14): load_class('Custom_library') #1 /home/gp/public_html/system/core/Common.php(478): MY_Log->write_log('error', 'Severity: error...') #2 /home/gp/public_html/system/core/Exceptions.php(105): log_message('error', 'Severity: error...') #3 /home/gp/public_html/system/core/Common.php(662): CI_Exceptions->log_exception('error', 'Exception: Clas...', '/home/gp/public...', 196) #4 [internal function]: _exception_handler(Object(Error)) #5 {main} thrown in /home/gp/public_html/system/core/Common.php on line 196

Answer 1

如果您需要访问其他库，扩展CI_Log将不起作用。原因是在CI_Log创建之前很久就创建了$CI，因此&get_instance()没有“实例”可供返回。

$this->load不起作用，因为$this不是控制器（$this且$CI指向同一个对象）和类load（' CI_Loader'）尚未创建。

这可能有不止一种方法。在我看来，最不被黑客攻击的方法是让您的记录器类使用CI_Log代替extend。

<强>应用/库/ Logger.php

class Logger
{
    protected $CI;

    public function __construct()
    {
        $this->CI = & get_instance();
        $this->CI->load->library('custom_library');
    }

    public function write_log($level, $msg)
    {
        //do stuff with "custom_library"
         $this->CI->custom_library->some_function();

        //use the built-in logging mechanism, a.k.a. CI_Log
        return log_message($level, $msg);
    }

}

您的`logger'需要在Controller中加载，与其他库一样。

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

用法示例可能是这样的

$this->logger->write_log('error', "This is FUBAR");

当您致电$this->load->library('logger');时，log类已创建并且属于$CI（a.k.a。$this）。所以这一行

    //use the built-in logging mechanism, a.k.a. CI_Log
    return log_message($level, $msg);

可以这样做而不是

    //use the built-in logging mechanism, a.k.a. CI_Log
    return $this->CI->log->write_log($level, $msg);

这会稍微提高效率，因为无论如何log_message所做的就是调用log->write_log。我没有看到任何问题，而不是使用log_message。

有趣的问题，我通过研究了解了很多。感谢。

Codeigniter：在核心类

更新

1 个答案: