CodeIgniter.php 執行流程分析 這是系統初始化文件 1.定義CI版本 2.定義CI分支 這裡我認為CI有兩個分支一個是Core ，另一個是Reactor。但是這裡具體的作用我還沒弄白。 3.加載全局函數system/core/common.php 4.加載框架常量 如果定義了ENVIRONMENT常量並且在APPPATH/cofig/下面有以ENVIRONMENT常量為名字的文件夾並且裡面存在constants.php則加載這個constants.php 如果沒有則直接加載APPPATH/cofig/下面的constants.php 5.定義一個自定義的錯誤處理函數，讓我們用來記錄php錯誤日志 6.如果當前php版本>5.3 則關閉魔術轉義 7.設置類前綴（在index.php中可以通過$assign_to_config[]來自定義配置項） 一般的類前綴會在config文件中被設置，這個類前綴可以讓CI知道application下的libraries文件夾下哪些的類繼承了CI核心類的類，因為CI容許入口文件index.php中覆蓋配置文件的配置項，所以程序開始執行之前我們需要知道類前綴是否被覆蓋，如果被覆蓋了，我們將在所有類加載之前設置它的值。 8.設置腳本執行時間 9.腳本開始執行 加載並實例化基准測試類（類文件：core/Benchmark.php） 記下total_execution_time_start 、loading_time:_base_classes_start這兩個時間點 10、如果可以加載並實例化鉤子類 （類文件core/Hooks.php）我們就加載並實例化 這需要在鉤子是在 application/config/config.php 中開啟並在 application/config/hooks.php文件中定義當前的鉤子 詳情：http://codeigniter.org.cn/user_guide/general/hooks.html 11.加載並實例化配置類 如果我們在index.php中手動的通過$assign_to_config[]來進行配置 12、加載並實例化UTF-8類，這裡的順序是非常重要的UTF-8類必須跟在配置類的後面加載 13、加載並實例化URI類 14、加載並實例化router類，設置router 15、加載並實例化輸出類 16、判斷有沒有緩存文件如果有輸出 17、為了防止xss和csrf攻擊加載並實例化security類 18、加載並實例化輸入類 19、加載並實例化語言包 20、加載並實例化控制器類 get_instance() 這個函數用於實例化控制器類 21、判斷是否存在子控制器類 如果存在加載 22、通過控制器去加載本地應用程序下請求的控制器 23、記錄loading_time:_base_classes_end時間點 24、進行安全監測 此處有說明：所有的功能不管是應用程序控制器還是加載類可以通過URI調用,控制器function不能用下劃線開始 先通過控制器獲得加載的類和方法 當加載的類或者方法又或者方法不在CI_Controller這個類中的時候，顯示404頁面 25、如果設置了pre_controller這個鉤子則調用 26、記錄請求控制器的時間並且實例化請求的類 27、如果設置了post_controller_constructor這個鉤子則調用 28、調用請求的方法 首先監測請求的類中是否有_remap方法，如果有調用 如果沒有再判斷請求的類中是否有請求的方法如果沒有顯示404頁面 最後調用請求的方法 29、記錄控制器執行結束的時間 30、如果設置了post_controller這個鉤子則調用 31、將最終的輸出發送到浏覽器 32、如果設置了post_system鉤子則調用 33、判斷CI_DB類是否存在還有$CI->db是否設置了值如果為真則關閉數據庫連接。 下面是文件源碼： [php] <?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); /** * CodeIgniter * * An open source application development framework for PHP 5.1.6 or newer * * @package CodeIgniter * @author ExpressionEngine Dev Team * @copyright Copyright (c) 2008 - 2011, EllisLab, Inc. * @license http://codeigniter.com/user_guide/license.html * @link http://codeigniter.com * @since Version 1.0 * @filesource */ // ------------------------------------------------------------------------ /** * System Initialization File * * Loads the base classes and executes 執行 the request. * * @package CodeIgniter * @subpackage codeigniter * @category Front-controller * @author ExpressionEngine Dev Team * @link http://codeigniter.com/user_guide/ */ /** * CodeIgniter Version * * @var string * */ define('CI_VERSION', '2.1.3'); /** * CodeIgniter Branch 分支 (Core = TRUE, Reactor 反應器 = FALSE) * * @var boolean * */ define('CI_CORE', FALSE); /* * ------------------------------------------------------ * Load the global functions * ------------------------------------------------------ */ require(BASEPATH.'core/Common.php'); /* * ------------------------------------------------------ * Load the framework constants * ------------------------------------------------------ */ if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/constants.php')) { require(APPPATH.'config/'.ENVIRONMENT.'/constants.php'); } else { require(APPPATH.'config/constants.php'); } /* * ------------------------------------------------------ * Define a custom 自定義 error handler 處理器 so we can log PHP errors * ------------------------------------------------------ */ set_error_handler('_exception_handler'); if ( ! is_php('5.3')) { @set_magic_quotes_runtime(0); // Kill magic quotes 關閉魔術轉義 } /* * ------------------------------------------------------ * Set the subclass_prefix 類前綴 * ------------------------------------------------------ * * Normally the "subclass_prefix" is set in the config file. * The subclass prefix allows CI to know if a core class is * being extended via 通過 a library in the local application * "libraries" folder. Since 因為 CI allows config items to be * overriden via data set in the main index. php file, * before proceeding 開始 、程序 we need to know if a subclass_prefix * override exists. 存在 If so, we will set this value now, * before any 任何 classes are loaded * Note: Since the config file data is cached it doesn't * hurt 傷害，使受傷 to load it here. * 注意：因為配置文件的數據已經被緩存，所以它加載到這裡也不會有傷害。 */ if (isset($assign_to_config['subclass_prefix']) AND $assign_to_config['subclass_prefix'] != '') { get_config(array('subclass_prefix' => $assign_to_config['subclass_prefix'])); } /* * ------------------------------------------------------ * Set a liberal 自由主義者 script execution 執行 time limit * ------------------------------------------------------ */ if (function_exists("set_time_limit") == TRUE AND @ini_get("safe_mode") == 0) { @set_time_limit(300); } /* * ------------------------------------------------------ * Start the timer... tick tock tick tock... * ------------------------------------------------------ */ $BM =& load_class('Benchmark', 'core'); $BM->mark('total_execution_time_start'); $BM->mark('loading_time:_base_classes_start'); /* * ------------------------------------------------------ * Instantiate the hooks class * ------------------------------------------------------ */ $EXT =& load_class('Hooks', 'core'); /* * ------------------------------------------------------ * Is there a "pre_system" hook? * ------------------------------------------------------ */ $EXT->_call_hook('pre_system'); /* * ------------------------------------------------------ * Instantiate the config class * ------------------------------------------------------ */ $CFG =& load_class('Config', 'core'); // Do we have any manually 手動的 set config items in the index.php file? if (isset($assign_to_config)) { $CFG->_assign_to_config($assign_to_config); } /* * ------------------------------------------------------ * Instantiate the UTF-8 class * ------------------------------------------------------ * * Note: Order 命令順序 here is rather 寧可，當然 important as the UTF-8 * class needs to be used very early 早期的，提早 on, but it cannot * properly 適當的、正確的 determine 決定 if UTf-8 can be supported until 在。。。以前 * after the Config class is instantiated. * */ $UNI =& load_class('Utf8', 'core'); /* * ------------------------------------------------------ * Instantiate the URI class * ------------------------------------------------------ */ $URI =& load_class('URI', 'core'); /* * ------------------------------------------------------ * Instantiate the routing class and set the routing * ------------------------------------------------------ */ $RTR =& load_class('Router', 'core'); $RTR->_set_routing(); // Set any routing overrides that may exist in the main index file if (isset($routing)) { $RTR->_set_overrides($routing); } /* * ------------------------------------------------------ * Instantiate the output class * ------------------------------------------------------ */ $OUT =& load_class('Output', 'core'); /* * ------------------------------------------------------ * Is there a valid 有效的 cache file? If so, we're done... * ------------------------------------------------------ */ if ($EXT->_call_hook('cache_override') === FALSE) { if ($OUT->_display_cache($CFG, $URI) == TRUE) { exit; } } /* * ----------------------------------------------------- * Load the security 安全 class for xss and csrf support * ----------------------------------------------------- */ $SEC =& load_class('Security', 'core'); /* * ------------------------------------------------------ * Load the Input class and sanitize 使。。。無害 globals * ------------------------------------------------------ */ $IN =& load_class('Input', 'core'); /* * ------------------------------------------------------ * Load the Language class * ------------------------------------------------------ */ $LANG =& load_class('Lang', 'core'); /* * ------------------------------------------------------ * Load the app controller and local controller * ------------------------------------------------------ * */ // Load the base controller class require BASEPATH.'core/Controller.php'; function &get_instance() { return CI_Controller::get_instance(); } if (file_exists(APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller.php')) { require APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller.php'; } // Load the local application controller // Note: The Router class automatically 不經思索的、自動的 validates 確認 the controller // path using the router->_validate_request(). // If this include fails it means 手段、意思是 that 因為、那麼 the default controller in // the Routes.php fi.le is not resolving 解析 to something 非常 valid 有效地 if ( ! file_exists(APPPATH.'controllers/'.$RTR->fetch_directory().$RTR->fetch_class().'.php')) { show_error('Unable to load your default controller. Please make sure the controller specified in your Routes.php file is valid.'); } include(APPPATH.'controllers/'.$RTR->fetch_directory().$RTR->fetch_class().'.php'); // Set a mark point for benchmarking 管理標記 $BM->mark('loading_time:_base_classes_end'); /* * ------------------------------------------------------ * Security check * ------------------------------------------------------ * * None of the functions in the app controller or the * loader class can be called via the URI, nor 也不是、也沒有 can * controller functions that begin with an underscore 下劃線、強調、底線 * 所有的功能不管是應用程序控制器還是加載類可以通過URI調用,控制器function不能用下劃線開始 */ $class = $RTR->fetch_class(); $method = $RTR->fetch_method(); if ( ! class_exists($class) OR strncmp($method, '_', 1) == 0 OR in_array(strtolower($method), array_map('strtolower', get_class_methods('CI_Controller'))) ) { if ( ! emptyempty($RTR->routes['404_override'])) { $x = explode('/', $RTR->routes['404_override']); $class = $x[0]; $method = (isset($x[1]) ? $x[1] : 'index'); if ( ! class_exists($class)) { if ( ! file_exists(APPPATH.'controllers/'.$class.'.php')) { show_404("{$class}/{$method}"); } include_once(APPPATH.'controllers/'.$class.'.php'); } } else { show_404("{$class}/{$method}"); } } /* * ------------------------------------------------------ * Is there a "pre_controller" hook? * ------------------------------------------------------ */ $EXT->_call_hook('pre_controller'); /* * ------------------------------------------------------ * Instantiate the requested controller * ------------------------------------------------------ */ // Mark a start point so we can benchmark the controller $BM->mark('controller_execution_time_( '.$class.' / '.$method.' )_start'); $CI = new $class(); /* * ------------------------------------------------------ * Is there a "post_controller_constructor" hook? * ------------------------------------------------------ */ $EXT->_call_hook('post_controller_constructor'); /* * ------------------------------------------------------ * Call the requested method * ------------------------------------------------------ */ // Is there a "remap" 重測圖、再交換 function? If so, we call it instead 更換、代替 if (method_exists($CI, '_remap')) { $CI->_remap($method, array_slice($URI->rsegments, 2)); } else { // is_callable() returns TRUE on some versions of PHP 5 for private and protected // methods, so we'll use this workaround 變通方案 for consistent behavior 一致的行為 if ( ! in_array(strtolower($method), array_map('strtolower', get_class_methods($CI)))) { // Check and see if we are using a 404 override and use it. if ( ! emptyempty($RTR->routes['404_override'])) { $x = explode('/', $RTR->routes['404_override']); $class = $x[0]; $method = (isset($x[1]) ? $x[1] : 'index'); if ( ! class_exists($class)) { if ( ! file_exists(APPPATH.'controllers/'.$class.'.php')) { show_404("{$class}/{$method}"); } include_once(APPPATH.'controllers/'.$class.'.php'); unset($CI); $CI = new $class(); } } else { show_404("{$class}/{$method}"); } } // Call the requested method. // Any URI segments 片段 present 禮物、現在、目前 (besides 除了。。。之外 the class/function) // will be passed to the method for convenience 便利、方便 call_user_func_array(array(&$CI, $method), array_slice($URI->rsegments, 2)); } // Mark a benchmark end point $BM->mark('controller_execution_time_( '.$class.' / '.$method.' )_end'); /* * ------------------------------------------------------ * Is there a "post_controller" hook? * ------------------------------------------------------ */ $EXT->_call_hook('post_controller'); /* * ------------------------------------------------------ * Send the final rendered 提出、已渲染的 output to the browser * ------------------------------------------------------ */ if ($EXT->_call_hook('display_override') === FALSE) { $OUT->_display(); } /* * ------------------------------------------------------ * Is there a "post_system" hook? * ------------------------------------------------------ */ www.2cto.com $EXT->_call_hook('post_system'); /* * ------------------------------------------------------ * Close the DB connection if one exists * ------------------------------------------------------ */ if (class_exists('CI_DB') AND isset($CI->db)) { $CI->db->close(); } /* End of file CodeIgniter.php */ /* Location: ./system/core/CodeIgniter.php */
