PHPCodeIgniter framework source code analysis

1. index. php: the entry file define (ENVIRONMENT) is mainly used to set the errors log output level -- $ system_path to set the system path -- set BASEPATH, FCPATH, SYSDIR, APPPATH, and so on | sets the path information variable, prepare for loading the corresponding file information -- require_onceBASEPATH.coreCodeIgniter.php | last

1. index. php: the entry file -- define ('Environment ') is mainly used to set the errors log output level -- $ system_path to set the system path -- set BASEPATH, FCPATH, SYSDIR, and APPPATH | set the path information variable, prepare -- require_once BASEPATH for loading the corresponding file information. core/CodeIgniter. php | last

1. index. php: entry file | --> define ('enable ') | mainly used to set the errors log output level | --> $ system_path | set the system path | --> set BASEPATH, FCPATH, SYSDIR, and APPPATH | set the path information variable, prepare for loading the corresponding file information | --> require_once BASEPATH. core/CodeIgniter. php | finally load CodeIgniter. php as the controller 2. codeIgniter. php is mainly used to load the corresponding files in the core directory of the core. | --> require (BASEPATH. 'Core/Common. php '); | loads the Common file under the core directory. For details, see "2.1 parsing | --> require (APPPATH. 'config /'. ENVIRONMENT. '/constants. php '); | load the constants object Recording, use the constants directory in the config directory if it is not related to the development environment | --> get_config (array ('subclass _ prefix' => $ assign_to_config ['subclass _ prefix']); | sets the subfile and prefix of the extension class | --> $ BM = & load_class ('benchmark', 'core'); | loads the Benchmark class, mark records the current time | --> $ EXT = & load_class ('hooks', 'core '); | load the Hooks hook class under the core directory | --> $ EXT-> _ call_hook ('pre _ system'); | call _ call_hook (pre_system ), execute the hook by calling _ run_hook in pre_system and preprocessing before the system starts to work. | --> $ CFG = & load_class ('config', 'c Ore '); | continue to execute the Config configuration file under the core, | --> $ CFG-> _ assign_to_config ($ assign_to_config ); | --> | $ this-> set_item ($ key, $ val); | parses the configuration file specified to config, essentially assign a value to config [] | --> $ UNI = & load_class ('utf8', 'core'); | loads the UTF-8 encoding class, CI_Utf8 | --> $ URI = & load_class ('uri ', 'core'); | URI class for loading the core directory, CI_URI | --> $ RTR = & load_class ('router ', 'core'); | sets route and overwrite information for route. For details, see section 2.2. | --> _ set_routing () | --> _ set_overrides () | --> $ OUT = & load_class ('output', 'c Ore '); | instantiate the output class and load the output file under the core directory | --> $ OUT-> _ display_cache ($ CFG, $ URI) | determine whether the page cache exists, yes, the output file | --> $ SEC = & load_class ('security', 'core '); | load the Security processing file under the core directory | --> $ IN = & load_class ('input', 'core'); | instantiate the Input class, load the input file in the core directory | --> $ LANG = & load_class ('lang ', 'core'); | load the language class | --> require BASEPATH. 'Core/Controller. php'; | load the basic controller class. For details, see Section 2.3. | --> require APPPATH. 'Core /'. $ CFG-> config ['subclass _ prefix']. 'controller. php'; | Try to load the extended custom subclass controller | --> include (APPPATH. 'controllers /'. $ RTR-> fetch_directory (). $ RTR-> fetch_class (). '. php '); | loads the Controller class under the custom controller | --> $ BM-> mark ('loading _ time: _ base_classes_end '); | set a benchmark test point | --> $ class = $ RTR-> fetch_class (); | controller class name and method name for obtaining uri addresses respectively | --> $ method = $ RTR-> fetch_method (); | --> if (! Class_exists ($ class) | judge whether the methods and classes are reasonable OR strncmp ($ method, '_', 1) = 0OR in_array (strtolower ($ method ), array_map ('strlower ', get_class_methods ('Ci _ controller') | --> $ EXT-> _ call_hook ('pre _ controller '); | pre-process the processor before execution and set the benchmark | --> $ CI = new $ class (); | obtains the Controller instance for execution, instantiate the constructor | --> $ EXT-> _ call_hook ('Post _ controller_constructor '); | hook processing after instantiating the Controller class | --> if (method_exists ($ CI, '_ remap') | --> $ CI-> _ remap ($ method, array_slice ($ URI-> rsegments, 2) | if the Controller has the _ remap () method, run the command. The judgment condition $ CI is the Controller class. | --> else | the Judgment Method in the class seems to exist. If not, set | --> call_user_func_array (array (& $ CI, $ method), array_slice ($ URI-> rsegments, 2 )); | the final parameter is passed for calling the control method. | --> $ BM-> mark ('controller _ execution_time _('. $ class. '/'. $ method. ') _ end'); | benchmark end Time | --> $ EXT-> _ call_hook ('Post _ controller'); | controller lifecycle, perform subsequent operations after the Controller completes | --> $ OUT-> _ display (); | display the output page | --> $ EXT-> _ call_hook ('Post _ system '); | end operation after the request lifecycle is completed | --> $ CI-> db-> close (); | automatically closes database resource 2.1 Core/Common. php loading | --> function is_php ($ version) | a function used to compare the version number | --> function is_really_writable ($ file) | used to determine whether a file can be written, reliability varies in different systems. In W, is_readonly is determined. In U, if safe_mode is enabled, uncertainty is obtained. | --> function load_class ($ class, $ directory = 'libraries ', $ prefix = 'Ci _ ') | class used to load the PHP file in the directory | --> foreach (array (APPPATH, BASEPATH) as $ path) | perform the next cycle in the application and system directories. | --> file_exists ($ path. $ directory. '/'. $ class. '. php' | find the corresponding php file | --> require ($ path. $ directory. '/'. $ class. '. php '); | require loads the class in the corresponding php file with a prefix, which can be expanded here | --> break; | exit if the file is loaded correctly, otherwise, try to load the file again. | --> file_exists (APPPATH. $ directory. '/'. config_item ('subclass _ prefix '). $ class. '. php ') | self-extended class, such as My_Test | --> if ($ name = FALSE) | exit () if $ name does not exist, (When a custom class is loaded, this can be used as an extension point to add marginal conditions) | --> is_loaded ($ class ); | indeed the class has been loaded | --> $ _ classes [$ class] = new $ name (); | load to the static classes ancestor for caching, obtain from classes when calling | --> function is_loaded ($ class = '') | --> sets the $ _ is_loaded ancestor. The parameter $ class is not empty, determine whether gf $ _ is_loaded exists; otherwise, it is set | --> function & get_config ($ replace = array () | used to obtain the instantiated Config file | --> static $ _ config; | define the config type | --> $ file_path = APPPATH. 'config/config. php'; | determine the config defined under the application directory path. php path | --> require ($ file_path); | load application/config. php class | --> count ($ replace)> 0 | for config. variables defined in php are replaced one by one if replace exists. | --> foreach ($ replace as $ key => $ val) | --> $ config [$ key] = $ val; | --> return $ _ config [0] = & $ config; | Finally, return the result set of the defined config | --> function config_item ($ item) | configuration options, return special configuration items from the config's ancestor object | --> $ config = & get_config (); | --> $ _ config_item [$ item] = $ config [$ item]; | --> function show_error | output of error information | --> $ _ error = & load_class ('exception', 'core '); | load Exceptions class | --> echo $ _ error-> show_error ($ heading, $ message, 'error _ general ', $ status_code ); | direct output error | --> function show_404 | used to output the 404 page, the output error message page can be configured. | --> function log_message | used to write log information | --> $ _ Log = & load_class ('log '); | --> $ _ log-> write_log ($ level, $ message, $ php_error ); | --> function set_status_header | heade information used to output status | --> function _ exception_handler | --> function remove_invisible_characters | --> function html_escape | filter HTML variables | --> return htmlspecialchars ($ var, ENT_QUOTES, config_item ('charset'); 2.2Router route information Settings | --> _ set_routing () | --> $ segments = array () | according to the directory, controller, the trigger of the function sets the uri segment value of the segment [], respectively. The fetch () method gets the object Value | --> include (APPPATH. 'config/routes. php '); | loads the routes file under config | --> $ this-> routes | sets the routes ancestor value, GET | --> $ this-> default_controller | set the Controller value of routes, GET | --> return $ this-> _ validate_request ($ segments) from the config route ); | verify the validity of the uri's segment | --> $ this-> uri-> _ remove_url_suffix (); $ this-> uri-> _ reindex_segments (); | further clears the parsing uri, make segment start from 1 x | --> _ set_overrides () | according to the value of $ routing, reset the directory, controller, and function parameters. | --> $ this-> set_directory ($ routing ['directory']); | --> $ this-> set_class ($ routing ['controller']); | --> $ this-> set_method ($ routing ['function']); 2.3 core/Controller. php loading | -- >__ construct () | constructor | --> self: $ instance = & $ this; | --> foreach (is_loaded () as $ var => $ class) | loads the corresponding class based on is_loaded () | --> $ this-> $ var = & load_class ($ class ); | --> $ this-> load = & load_class ('loader ', 'core '); | load the PHP file of core/Loader | --> $ this-> load-> initialize (); | mainly used for autoload loading information, such as libraries and database | --> function & get_instance | returns the current instance | --> return self: $ instance extension point: Application of PHP automatic loading mechanism in CodeIgniter 1. PHP automatic loading mechanism: After PHP5, the automatic loading mechanism of the class is provided, that is, the class is used only during loading, that is, Lazy loading. There are two ways: 1.1: _ autoload () you can achieve this through extension. In essence, it is to set the rules to load the PHP file of the corresponding path (require, include mode) 1.2: Point autoload_func to the PHP file. For details, refer to the C language extension implementation: http://blog.csdn.net/flyingpig4/article/details/72864382 . According to the above source code analysis, the application in CodeIgniter shows that all the operations in CodeIgniter start with Controller. You only need to make the _ autoload () function automatically load during Cotroller loading, the current loading method is in application/config. set the _ autoload () function in php.

Original article address: PHP CodeIgniter framework source code parsing. Thank you for sharing it with me.