系統初始化文件 · php CI 框架源碼閱讀筆記

文件位置：Location: ./system/core/CodeIgniter.php 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 ?這里我認為CI有兩個分支一個是Core ，另一個是Reactor。但是這里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常量并且在APPPATH/cofig/下面有以ENVIRONMENT常量為名字的文件夾并且里面存在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$assign_to_config[]來自定義配置項）一般的類前綴會在config文件中被設置，這個類前綴可以讓CI知道application下的libraries文件夾下哪些的類繼承了CI核心類的類，因為CI容許入口文件index.php中覆蓋配置文件的配置項，所以程序開始執行之前我們需要知道類前綴是否被覆蓋，如果被覆蓋了，我們將在所有類加載之前設置它的值。 8.設置腳本執行時間 9.腳本開始執行加載并實例化基準測試類（類文件：core/Benchmark.php）記下total_execution_time_start 、loading_time:_base_classes_start這兩個時間點 10、如果可以加載并實例化鉤子類（類文件core/Hooks.php）我們就加載并實例化這需要在鉤子是在 application/config/config.php 中開啟并在 application/config/hooks.php文件中定義當前的鉤子詳情：http://codeigniter.org.cn/user_guide/general/hooks.html 11.加載并實例化配置類如果我們在index.php中手動的通過$assign_to_config[]來進行配置 12、加載并實例化UTF-8類，這里的順序是非常重要的UTF-8類必須跟在配置類的后面加載 13、加載并實例化URI類 14、加載并實例化router類，設置router 15、加載并實例化輸出類 16、判斷有沒有緩存文件如果有輸出 17、為了防止xss和csrf攻擊加載并實例化security類 18、加載并實例化輸入類 19、加載并實例化語言包 20、加載并實例化控制器類 get_instance() 這個函數用于實例化控制器類 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并且實例化請求的類 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頁面最后調用請求的方法 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瀏覽器 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 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，所以它加載到這里也不會有傷害。 */ 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/'.$CFG->config['subclass_prefix'].'Controller.php'; } // Load the local application controller // Note: The Router class automatically 不經思索的、自動的 validates 確認 the controller // path using the router->_validate_request(). // If this include fails it means 手段、意思是 that 因為、那么 the default controller in // the Routes.php fi.le is not resolving 解析 to something 非常 valid 有效地 if ( ! file_exists(APPPATH.'controllers/'.$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 ( ! empty($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($CI)))) { // Check and see if we are using a 404 override and use it. if ( ! empty($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? * ------------------------------------------------------ */ $EXT->_call_hook('post_system'); /* * ------------------------------------------------------ * Close the DB connection if one exists * ------------------------------------------------------ */ if (class_exists('CI_DB') AND isset($CI->db)) { $CI->db->close(); } /* End of file CodeIgniter.php */ /* Location: ./system/core/CodeIgniter.php */ ~~~