codeigniter源代码分析 - 错误处理类 Exception.php

剩下的class 都比较简单但是作用很大 框架必不可少的功能部分

Exception      错误处理 404 php error

Benchmark   检测CI运行加载时间 内存使用情况

Hooks            钩子程序 便于对CI扩展 主要作用是 能通过钩子 在CI的执行流程中添加一些自己的实现

Lang               语言加载

先写Exception 注释源码：

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
class CI_Exceptions {
var $action;
var $severity;
var $message;
var $filename;
var $line;
var $ob_level;
var $levels = array(
E_ERROR => 'Error',
E_WARNING => 'Warning',
E_PARSE => 'Parsing Error',
E_NOTICE => 'Notice',
E_CORE_ERROR => 'Core Error',
E_CORE_WARNING => 'Core Warning',
E_COMPILE_ERROR => 'Compile Error',
E_COMPILE_WARNING => 'Compile Warning',
E_USER_ERROR => 'User Error',
E_USER_WARNING => 'User Warning',
E_USER_NOTICE => 'User Notice',
E_STRICT => 'Runtime Notice'
);

/**
* Constructor
*/
public function __construct()
{
// 缓存嵌套级别
// Note: Do not log messages from this constructor.
$this->ob_level = ob_get_level();
}
function log_exception($severity, $message, $filepath, $line)
{
$severity = ( ! isset($this->levels[$severity])) ? $severity : $this->levels[$severity];

log_message('error', 'Severity: '.$severity.' --> '.$message. ' '.$filepath.' '.$line, TRUE);
}
function show_404($page = '', $log_error = TRUE)
{
$heading = "404 Page Not Found";
$message = "The page you requested was not found.";

// By default we log this, but allow a dev to skip it
if ($log_error)
{
log_message('error', '404 Page Not Found --> '.$page);
}
// 增加404http头信息 调用show_error()
echo $this->show_error($heading, $message, 'error_404', 404);
exit;
}
function show_error($heading, $message, $template = 'error_general', $status_code = 500)
{
// 设置http 响应头信息
set_status_header($status_code);

$message = '<p>'.implode('</p><p>', ( ! is_array($message)) ? array($message) : $message).'</p>';

if (ob_get_level() > $this->ob_level + 1)
{
ob_end_flush();
}
ob_start();
// 引入错误提示模版
include(APPPATH.'errors/'.$template.'.php');
$buffer = ob_get_contents();
ob_end_clean();
// 返回错误信息
return $buffer;
}
function show_php_error($severity, $message, $filepath, $line)
{
$severity = ( ! isset($this->levels[$severity])) ? $severity : $this->levels[$severity];

$filepath = str_replace("\\", "/", $filepath);

// For safety reasons we do not show the full file path
// 解释的挺清除 wo don't show the full path
// filepath 变量会在error模版中使用
if (FALSE !== strpos($filepath, '/'))
{
$x = explode('/', $filepath);
$filepath = $x[count($x)-2].'/'.end($x);
}

if (ob_get_level() > $this->ob_level + 1)
{
ob_end_flush();
}
ob_start();
include(APPPATH.'errors/error_php.php');
$buffer = ob_get_contents();
ob_end_clean();
echo $buffer;
}
}
Code Tips：
show_404 -> show_error

                         show_php_error

主要起作用的方法是 show_error and show_php_error

show_error 用户可以自行调用显示错误 类似exit()

show_php_error 是对php发生用户级别的错误时候进行的处理

需要学习其中用ob进行输出的思想