顾名思义，装载器就是加载元素的，使用CI时，经常加载的有：
加载类库文件：$this->load->library()
加载视图文件：$this->load->view()
加载模型文件：$this->load->model()
加载数据库文件：$this->load->database()
加载帮助文件：$this->load->helper()
加载配置文件：$this->load->config()
加载包路径：$this->load->add_package_path()
源码：
1 /**
2 * Loader Class
3 *
4 * 用户加载views和files，常见的函数有model(),view(),library(),helper()
5 *
6 * Controller的好助手，$this->load =& load_class(‘Loader‘, ‘core‘);，加载了loader，Controller就无比强大了
7 * @link http://www.phpddt.com
8 */
9 class CI_Loader {
10
11 protected $_ci_ob_level;
12
13 protected $_ci_view_paths = array();
14 protected $_ci_library_paths = array();
15 protected $_ci_model_paths = array();
16 protected $_ci_helper_paths = array();
17
18 protected $_base_classes = array(); // Set by the controller class
19
20 protected $_ci_cached_vars = array();
21
22 protected $_ci_classes = array();
23
24 protected $_ci_loaded_files = array();
25
26 protected $_ci_models = array();
27
28 protected $_ci_helpers = array();
29
30 protected $_ci_varmap = array(‘unit_test‘ => ‘unit‘,
31 ‘user_agent‘ => ‘agent‘);
32
33 public function __construct()
34 {
35 //获取缓冲嵌套级别
36 $this->_ci_ob_level = ob_get_level();
37 //library路径
38 $this->_ci_library_paths = array(APPPATH, BASEPATH);
39 //helper路径
40 $this->_ci_helper_paths = array(APPPATH, BASEPATH);
41 //model路径
42 $this->_ci_model_paths = array(APPPATH);
43 //view路径
44 $this->_ci_view_paths = array(APPPATH.‘views/‘ => TRUE);
45
46 log_message(‘debug‘, "Loader Class Initialized");
47 }
48
49 // --------------------------------------------------------------------
50
51 /**
52 * 初始化Loader
53 *
54 */
55 public function initialize()
56 {
57 $this->_ci_classes = array();
58 $this->_ci_loaded_files = array();
59 $this->_ci_models = array();
60 //将is_loaded（common中记录加载核心类函数）加载的核心类交给_base_classes
61 $this->_base_classes =& is_loaded();
62
63 //加载autoload.php配置中文件
64 $this->_ci_autoloader();
65
66 return $this;
67 }
68
69 // --------------------------------------------------------------------
70
71 /**
72 * 检测类是否加载
73 */
74 public function is_loaded($class)
75 {
76 if (isset($this->_ci_classes[$class]))
77 {
78 return $this->_ci_classes[$class];
79 }
80
81 return FALSE;
82 }
83
84 // --------------------------------------------------------------------
85
86 /**
87 * 加载Class
88 */
89 public function library($library = ‘‘, $params = NULL, $object_name = NULL)
90 {
91 if (is_array($library))
92 {
93 foreach ($library as $class)
94 {
95 $this->library($class, $params);
96 }
97
98 return;
99 }
100
101 //如果$library为空或者已经加载。。。
102 if ($library == ‘‘ OR isset($this->_base_classes[$library]))
103 {
104 return FALSE;
105 }
106
107 if ( ! is_null($params) && ! is_array($params))
108 {
109 $params = NULL;
110 }
111
112 $this->_ci_load_class($library, $params, $object_name);
113 }
114
115 // --------------------------------------------------------------------
116
117 /**
118 * 加载和实例化model
119 */
120 public function model($model, $name = ‘‘, $db_conn = FALSE)
121 {
122 //CI支持数组加载多个model
123 if (is_array($model))
124 {
125 foreach ($model as $babe)
126 {
127 $this->model($babe);
128 }
129 return;
130 }
131
132 if ($model == ‘‘)
133 {
134 return;
135 }
136
137 $path = ‘‘;
138
139 // 是否存在子目录
140 if (($last_slash = strrpos($model, ‘/‘)) !== FALSE)
141 {
142 // The path is in front of the last slash
143 $path = substr($model, 0, $last_slash + 1);
144
145 // And the model name behind it
146 $model = substr($model, $last_slash + 1);
147 }
148
149 if ($name == ‘‘)
150 {
151 $name = $model;
152 }
153
154 if (in_array($name, $this->_ci_models, TRUE))
155 {
156 return;
157 }
158
159 $CI =& get_instance();
160 if (isset($CI->$name))
161 {
162 show_error(‘The model name you are loading is the name of a resource that is already being used: ‘.$name);
163 }
164
165 $model = strtolower($model); //model文件名全小写
166
167 foreach ($this->_ci_model_paths as $mod_path)
168 {
169 if ( ! file_exists($mod_path.‘models/‘.$path.$model.‘.php‘))
170 {
171 continue;
172 }
173
174 if ($db_conn !== FALSE AND ! class_exists(‘CI_DB‘))
175 {
176 if ($db_conn === TRUE)
177 {
178 $db_conn = ‘‘;
179 }
180
181 $CI->load->database($db_conn, FALSE, TRUE);
182 }
183
184 if ( ! class_exists(‘CI_Model‘))
185 {
186 load_class(‘Model‘, ‘core‘);
187 }
188
189 require_once($mod_path.‘models/‘.$path.$model.‘.php‘);
190
191 $model = ucfirst($model);
192
193 $CI->$name = new $model();
194 //保存在Loader::_ci_models中，以后可以用它来判断某个model是否已经加载过。
195 $this->_ci_models[] = $name;
196 return;
197 }
198
199 // couldn‘t find the model
200 show_error(‘Unable to locate the model you have specified: ‘.$model);
201 }
202
203 // --------------------------------------------------------------------
204
205 /**
206 * 数据库Loader
207 */
208 public function database($params = ‘‘, $return = FALSE, $active_record = NULL)
209 {
210 // Grab the super object
211 $CI =& get_instance();
212
213 // 是否需要加载db
214 if (class_exists(‘CI_DB‘) AND $return == FALSE AND $active_record == NULL AND isset($CI->db) AND is_object($CI->db))
215 {
216 return FALSE;
217 }
218
219 require_once(BASEPATH.‘database/DB.php‘);
220
221 if ($return === TRUE)
222 {
223 return DB($params, $active_record);
224 }
225
226 // Initialize the db variable. Needed to prevent
227 // reference errors with some configurations
228 $CI->db = ‘‘;
229
230 // Load the DB class
231 $CI->db =& DB($params, $active_record);
232 }
233
234 // --------------------------------------------------------------------
235
236 /**
237 * 加载数据库工具类
238 */
239 public function dbutil()
240 {
241 if ( ! class_exists(‘CI_DB‘))
242 {
243 $this->database();
244 }
245
246 $CI =& get_instance();
247
248 // for backwards compatibility, load dbforge so we can extend dbutils off it
249 // this use is deprecated and strongly discouraged
250 $CI->load->dbforge();
251
252 require_once(BASEPATH.‘database/DB_utility.php‘);
253 require_once(BASEPATH.‘database/drivers/‘.$CI->db->dbdriver.‘/‘.$CI->db->dbdriver.‘_utility.php‘);
254 $class = ‘CI_DB_‘.$CI->db->dbdriver.‘_utility‘;
255
256 $CI->dbutil = new $class();
257 }
258
259 // --------------------------------------------------------------------
260
261 /**
262 * Load the Database Forge Class
263 *
264 * @return string
265 */
266 public function dbforge()
267 {
268 if ( ! class_exists(‘CI_DB‘))
269 {
270 $this->database();
271 }
272
273 $CI =& get_instance();
274
275 require_once(BASEPATH.‘database/DB_forge.php‘);
276 require_once(BASEPATH.‘database/drivers/‘.$CI->db->dbdriver.‘/‘.$CI->db->dbdriver.‘_forge.php‘);
277 $class = ‘CI_DB_‘.$CI->db->dbdriver.‘_forge‘;
278
279 $CI->dbforge = new $class();
280 }
281
282 // --------------------------------------------------------------------
283
284 /**
285 * 加载视图文件
286 */
287 public function view($view, $vars = array(), $return = FALSE)
288 {
289 return $this->_ci_load(array(‘_ci_view‘ => $view, ‘_ci_vars‘ => $this->_ci_object_to_array($vars), ‘_ci_return‘ => $return));
290 }
291
292 // --------------------------------------------------------------------
293
294 /**
295 * 加载普通文件
296 */
297 public function file($path, $return = FALSE)
298 {
299 return $this->_ci_load(array(‘_ci_path‘ => $path, ‘_ci_return‘ => $return));
300 }
301
302 // --------------------------------------------------------------------
303
304 /**
305 * 设置变量
306 *
307 * Once variables are set they become available within
308 * the controller class and its "view" files.
309 *
310 */
311 public function vars($vars = array(), $val = ‘‘)
312 {
313 if ($val != ‘‘ AND is_string($vars))
314 {
315 $vars = array($vars => $val);
316 }
317
318 $vars = $this->_ci_object_to_array($vars);
319
320 if (is_array($vars) AND count($vars) > 0)
321 {
322 foreach ($vars as $key => $val)
323 {
324 $this->_ci_cached_vars[$key] = $val;
325 }
326 }
327 }
328
329 // --------------------------------------------------------------------
330
331 /**
332 * 检查并获取变量
333 */
334 public function get_var($key)
335 {
336 return isset($this->_ci_cached_vars[$key]) ? $this->_ci_cached_vars[$key] : NULL;
337 }
338
339 // --------------------------------------------------------------------
340
341 /**
342 * 加载helper
343 */
344 public function helper($helpers = array())
345 {
346 foreach ($this->_ci_prep_filename($helpers, ‘_helper‘) as $helper)
347 {
348 if (isset($this->_ci_helpers[$helper]))
349 {
350 continue;
351 }
352
353 $ext_helper = APPPATH.‘helpers/‘.config_item(‘subclass_prefix‘).$helper.‘.php‘;
354
355 // 如果是扩展helper的话
356 if (file_exists($ext_helper))
357 {
358 $base_helper = BASEPATH.‘helpers/‘.$helper.‘.php‘;
359
360 if ( ! file_exists($base_helper))
361 {
362 show_error(‘Unable to load the requested file: helpers/‘.$helper.‘.php‘);
363 }
364
365 include_once($ext_helper);
366 include_once($base_helper);
367
368 $this->_ci_helpers[$helper] = TRUE;
369 log_message(‘debug‘, ‘Helper loaded: ‘.$helper);
370 continue;
371 }
372
373 // 如果不是扩展helper，helper路径中加载helper
374 foreach ($this->_ci_helper_paths as $path)
375 {
376 if (file_exists($path.‘helpers/‘.$helper.‘.php‘))
377 {
378 include_once($path.‘helpers/‘.$helper.‘.php‘);
379
380 $this->_ci_helpers[$helper] = TRUE;
381 log_message(‘debug‘, ‘Helper loaded: ‘.$helper);
382 break;
383 }
384 }
385
386 // 如果该helper还没加载成功的话，说明加载helper失败
387 if ( ! isset($this->_ci_helpers[$helper]))
388 {
389 show_error(‘Unable to load the requested file: helpers/‘.$helper.‘.php‘);
390 }
391 }
392 }
393
394 // --------------------------------------------------------------------
395
396 /**
397 * 可以看到helpers调用也是上面的helper,只是helpers的别名而已
398 */
399 public function helpers($helpers = array())
400 {
401 $this->helper($helpers);
402 }
403
404 // --------------------------------------------------------------------
405
406 /**
407 * 加载language文件
408 */
409 public function language($file = array(), $lang = ‘‘)
410 {
411 $CI =& get_instance();
412
413 if ( ! is_array($file))
414 {
415 $file = array($file);
416 }
417
418 foreach ($file as $langfile)
419 {
420 $CI->lang->load($langfile, $lang);
421 }
422 }
423
424 // --------------------------------------------------------------------
425
426 /**
427 * 加载配置文件
428 */
429 public function config($file = ‘‘, $use_sections = FALSE, $fail_gracefully = FALSE)
430 {
431 $CI =& get_instance();
432 $CI->config->load($file, $use_sections, $fail_gracefully);
433 }
434
435 // --------------------------------------------------------------------
436
437 /**
438 * Driver
439 *
440 * 加载 driver library
441 */
442 public function driver($library = ‘‘, $params = NULL, $object_name = NULL)
443 {
444 if ( ! class_exists(‘CI_Driver_Library‘))
445 {
446 // we aren‘t instantiating an object here, that‘ll be done by the Library itself
447 require BASEPATH.‘libraries/Driver.php‘;
448 }
449
450 if ($library == ‘‘)
451 {
452 return FALSE;
453 }
454
455 // We can save the loader some time since Drivers will *always* be in a subfolder,
456 // and typically identically named to the library
457 if ( ! strpos($library, ‘/‘))
458 {
459 $library = ucfirst($library).‘/‘.$library;
460 }
461
462 return $this->library($library, $params, $object_name);
463 }
464
465 // --------------------------------------------------------------------
466
467 /**
468 * 添加 Package 路径
469 *
470 * 把package路径添加到库，模型，助手，配置路径
471 */
472 public function add_package_path($path, $view_cascade=TRUE)
473 {
474 $path = rtrim($path, ‘/‘).‘/‘;
475
476 array_unshift($this->_ci_library_paths, $path);
477 array_unshift($this->_ci_model_paths, $path);
478 array_unshift($this->_ci_helper_paths, $path);
479
480 $this->_ci_view_paths = array($path.‘views/‘ => $view_cascade) + $this->_ci_view_paths;
481
482 $config =& $this->_ci_get_component(‘config‘);
483 array_unshift($config->_config_paths, $path);
484 }
485
486 // --------------------------------------------------------------------
487
488 /**
489 * 获取Package Paths，默认不包含BASEPATH
490 */
491 public function get_package_paths($include_base = FALSE)
492 {
493 return $include_base === TRUE ? $this->_ci_library_paths : $this->_ci_model_paths;
494 }
495
496 // --------------------------------------------------------------------
497
498 /**
499 * 剔除Package Path
500 *
501 * Remove a path from the library, model, and helper path arrays if it exists
502 * If no path is provided, the most recently added path is removed.
503 *
504 */
505 public function remove_package_path($path = ‘‘, $remove_config_path = TRUE)
506 {
507 $config =& $this->_ci_get_component(‘config‘);
508
509 if ($path == ‘‘)
510 {
511 $void = array_shift($this->_ci_library_paths);
512 $void = array_shift($this->_ci_model_paths);
513 $void = array_shift($this->_ci_helper_paths);
514 $void = array_shift($this->_ci_view_paths);
515 $void = array_shift($config->_config_paths);
516 }
517 else
518 {
519 $path = rtrim($path, ‘/‘).‘/‘;
520 foreach (array(‘_ci_library_paths‘, ‘_ci_model_paths‘, ‘_ci_helper_paths‘) as $var)
521 {
522 if (($key = array_search($path, $this->{$var})) !== FALSE)
523 {
524 unset($this->{$var}[$key]);
525 }
526 }
527
528 if (isset($this->_ci_view_paths[$path.‘views/‘]))
529 {
530 unset($this->_ci_view_paths[$path.‘views/‘]);
531 }
532
533 if (($key = array_search($path, $config->_config_paths)) !== FALSE)
534 {
535 unset($config->_config_paths[$key]);
536 }
537 }
538
539 // 保证应用默认的路径依然存在
540 $this->_ci_library_paths = array_unique(array_merge($this->_ci_library_paths, array(APPPATH, BASEPATH)));
541 $this->_ci_helper_paths = array_unique(array_merge($this->_ci_helper_paths, array(APPPATH, BASEPATH)));
542 $this->_ci_model_paths = array_unique(array_merge($this->_ci_model_paths, array(APPPATH)));
543 $this->_ci_view_paths = array_merge($this->_ci_view_paths, array(APPPATH.‘views/‘ => TRUE));
544 $config->_config_paths = array_unique(array_merge($config->_config_paths, array(APPPATH)));
545 }
546
547 // --------------------------------------------------------------------
548
549 /**
550 * Loader
551 *
552 * This function is used to load views and files.
553 * Variables are prefixed with _ci_ to avoid symbol collision with
554 * variables made available to view files
555 *
556 * @param array
557 * @return void
558 */
559 protected function _ci_load($_ci_data)
560 {
561 // Set the default data variables
562 foreach (array(‘_ci_view‘, ‘_ci_vars‘, ‘_ci_path‘, ‘_ci_return‘) as $_ci_val)
563 {
564 $$_ci_val = ( ! isset($_ci_data[$_ci_val])) ? FALSE : $_ci_data[$_ci_val];
565 }
566
567 $file_exists = FALSE;
568 //如果$_ci_path不为空，则说明当前要加载普通文件。Loader::file才会有path
569 if ($_ci_path != ‘‘)
570 {
571 $_ci_x = explode(‘/‘, $_ci_path);
572 $_ci_file = end($_ci_x);
573 }
574 else
575 {
576 $_ci_ext = pathinfo($_ci_view, PATHINFO_EXTENSION);
577 $_ci_file = ($_ci_ext == ‘‘) ? $_ci_view.‘.php‘ : $_ci_view;
578
579 foreach ($this->_ci_view_paths as $view_file => $cascade)
580 {
581 if (file_exists($view_file.$_ci_file))
582 {
583 $_ci_path = $view_file.$_ci_file;
584 $file_exists = TRUE;
585 break;
586 }
587
588 if ( ! $cascade)
589 {
590 break;
591 }
592 }
593 }
594 //view文件不存在则会报错
595 if ( ! $file_exists && ! file_exists($_ci_path))
596 {
597 show_error(‘Unable to load the requested file: ‘.$_ci_file);
598 }
599
600 // 把CI的所有属性都传递给loader，view中$this指的是loader
601 $_ci_CI =& get_instance();
602 foreach (get_object_vars($_ci_CI) as $_ci_key => $_ci_var)
603 {
604 if ( ! isset($this->$_ci_key))
605 {
606 $this->$_ci_key =& $_ci_CI->$_ci_key;
607 }
608 }
609
610 /*
611 * Extract and cache variables
612 *
613 * You can either set variables using the dedicated $this->load_vars()
614 * function or via the second parameter of this function. We‘ll merge
615 * the two types and cache them so that views that are embedded within
616 * other views can have access to these variables.
617 */
618
619
620 if (is_array($_ci_vars))
621 {
622 $this->_ci_cached_vars = array_merge($this->_ci_cached_vars, $_ci_vars);
623 }
624
625 extract($this->_ci_cached_vars);
626
627 /*
628 * 将视图内容放到缓存区
629 *
630 */
631 ob_start();
632
633 // 支持短标签
634 if ((bool) @ini_get(‘short_open_tag‘) === FALSE AND config_item(‘rewrite_short_tags‘) == TRUE)
635 {
636 echo eval(‘?>‘.preg_replace("/;*\s*\?>/", "; ?>", str_replace(‘<?=‘, ‘<?php echo ‘, file_get_contents($_ci_path))));
637 }
638 else
639 {
640 include($_ci_path); // include() vs include_once() allows for multiple views with the same name
641 }
642
643 log_message(‘debug‘, ‘File loaded: ‘.$_ci_path);
644
645 // 是否直接返回view数据
646 if ($_ci_return === TRUE)
647 {
648 $buffer = ob_get_contents();
649 @ob_end_clean();
650 return $buffer;
651 }
652
653 //当前这个视图文件是被另一个视图文件通过$this->view()方法引入，即视图文件嵌入视图文件
654 if (ob_get_level() > $this->_ci_ob_level + 1)
655 {
656
657 ob_end_flush();
658 }
659 else
660 { ////把缓冲区的内容交给Output组件并清空关闭缓冲区。
661 $_ci_CI->output->append_output(ob_get_contents());
662 @ob_end_clean();
663 }
664 }
665
666 // --------------------------------------------------------------------
667
668 /**
669 * 加载类
670 */
671 protected function _ci_load_class($class, $params = NULL, $object_name = NULL)
672 {
673 // 去掉.php和两端的/获取的$class就是类名或目录名+类名
674 $class = str_replace(‘.php‘, ‘‘, trim($class, ‘/‘));
675
676 // CI允许dir/filename方式
677 $subdir = ‘‘;
678 if (($last_slash = strrpos($class, ‘/‘)) !== FALSE)
679 {
680 // 目录
681 $subdir = substr($class, 0, $last_slash + 1);
682
683 // 文件名
684 $class = substr($class, $last_slash + 1);
685 }
686
687 // 允许加载的类名首字母大写或全小写
688 foreach (array(ucfirst($class), strtolower($class)) as $class)
689 {
690 $subclass = APPPATH.‘libraries/‘.$subdir.config_item(‘subclass_prefix‘).$class.‘.php‘;
691
692 // 是否是扩展类
693 if (file_exists($subclass))
694 {
695 $baseclass = BASEPATH.‘libraries/‘.ucfirst($class).‘.php‘;
696
697 if ( ! file_exists($baseclass))
698 {
699 log_message(‘error‘, "Unable to load the requested class: ".$class);
700 show_error("Unable to load the requested class: ".$class);
701 }
702
703 // Safety: Was the class already loaded by a previous call?
704 if (in_array($subclass, $this->_ci_loaded_files))
705 {
706 // Before we deem this to be a duplicate request, let‘s see
707 // if a custom object name is being supplied. If so, we‘ll
708 // return a new instance of the object
709 if ( ! is_null($object_name))
710 {
711 $CI =& get_instance();
712 if ( ! isset($CI->$object_name))
713 {
714 return $this->_ci_init_class($class, config_item(‘subclass_prefix‘), $params, $object_name);
715 }
716 }
717
718 $is_duplicate = TRUE;
719 log_message(‘debug‘, $class." class already loaded. Second attempt ignored.");
720 return;
721 }
722
723 include_once($baseclass);
724 include_once($subclass);
725 $this->_ci_loaded_files[] = $subclass;
726 //实例化类
727 return $this->_ci_init_class($class, config_item(‘subclass_prefix‘), $params, $object_name);
728 }
729
730 // 如果不是扩展，和上面类似
731 $is_duplicate = FALSE;
732 foreach ($this->_ci_library_paths as $path)
733 {
734 $filepath = $path.‘libraries/‘.$subdir.$class.‘.php‘;
735
736 // Does the file exist? No? Bummer...
737 if ( ! file_exists($filepath))
738 {
739 continue;
740 }
741
742 // Safety: Was the class already loaded by a previous call?
743 if (in_array($filepath, $this->_ci_loaded_files))
744 {
745 // Before we deem this to be a duplicate request, let‘s see
746 // if a custom object name is being supplied. If so, we‘ll
747 // return a new instance of the object
748 if ( ! is_null($object_name))
749 {
750 $CI =& get_instance();
751 if ( ! isset($CI->$object_name))
752 {
753 return $this->_ci_init_class($class, ‘‘, $params, $object_name);
754 }
755 }
756
757 $is_duplicate = TRUE;
758 log_message(‘debug‘, $class." class already loaded. Second attempt ignored.");
759 return;
760 }
761
762 include_once($filepath);
763 $this->_ci_loaded_files[] = $filepath;
764 return $this->_ci_init_class($class, ‘‘, $params, $object_name);
765 }
766
767 } // END FOREACH
768
769 // 如果还没有找到该class，最后的尝试是该class会不会在同名的子目录下
770 if ($subdir == ‘‘)
771 {
772 $path = strtolower($class).‘/‘.$class;
773 return $this->_ci_load_class($path, $params);
774 }
775
776 // 加载失败，报错
777 if ($is_duplicate == FALSE)
778 {
779 log_message(‘error‘, "Unable to load the requested class: ".$class);
780 show_error("Unable to load the requested class: ".$class);
781 }
782 }
783
784 // --------------------------------------------------------------------
785
786 /**
787 * 实例化已经加载的类
788 */
789 protected function _ci_init_class($class, $prefix = ‘‘, $config = FALSE, $object_name = NULL)
790 {
791 // 是否有类的配置信息
792 if ($config === NULL)
793 {
794 // Fetch the config paths containing any package paths
795 $config_component = $this->_ci_get_component(‘config‘);
796
797 if (is_array($config_component->_config_paths))
798 {
799 // Break on the first found file, thus package files
800 // are not overridden by default paths
801 foreach ($config_component->_config_paths as $path)
802 {
803 // We test for both uppercase and lowercase, for servers that
804 // are case-sensitive with regard to file names. Check for environment
805 // first, global next
806 if (defined(‘ENVIRONMENT‘) AND file_exists($path .‘config/‘.ENVIRONMENT.‘/‘.strtolower($class).‘.php‘))
807 {
808 include($path .‘config/‘.ENVIRONMENT.‘/‘.strtolower($class).‘.php‘);
809 break;
810 }
811 elseif (defined(‘ENVIRONMENT‘) AND file_exists($path .‘config/‘.ENVIRONMENT.‘/‘.ucfirst(strtolower($class)).‘.php‘))
812 {
813 include($path .‘config/‘.ENVIRONMENT.‘/‘.ucfirst(strtolower($class)).‘.php‘);
814 break;
815 }
816 elseif (file_exists($path .‘config/‘.strtolower($class).‘.php‘))
817 {
818 include($path .‘config/‘.strtolower($class).‘.php‘);
819 break;
820 }
821 elseif (file_exists($path .‘config/‘.ucfirst(strtolower($class)).‘.php‘))
822 {
823 include($path .‘config/‘.ucfirst(strtolower($class)).‘.php‘);
824 break;
825 }
826 }
827 }
828 }
829
830 if ($prefix == ‘‘)
831 { //system下library
832 if (class_exists(‘CI_‘.$class))
833 {
834 $name = ‘CI_‘.$class;
835 }
836 elseif (class_exists(config_item(‘subclass_prefix‘).$class))
837 { //扩展library
838 $name = config_item(‘subclass_prefix‘).$class;
839 }
840 else
841 {
842 $name = $class;
843 }
844 }
845 else
846 {
847 $name = $prefix.$class;
848 }
849
850 // Is the class name valid?
851 if ( ! class_exists($name))
852 {
853 log_message(‘error‘, "Non-existent class: ".$name);
854 show_error("Non-existent class: ".$class);
855 }
856
857 // Set the variable name we will assign the class to
858 // Was a custom class name supplied? If so we‘ll use it
859 $class = strtolower($class);
860
861 if (is_null($object_name))
862 {
863 $classvar = ( ! isset($this->_ci_varmap[$class])) ? $class : $this->_ci_varmap[$class];
864 }
865 else
866 {
867 $classvar = $object_name;
868 }
869
870 // Save the class name and object name
871 $this->_ci_classes[$class] = $classvar;
872
873 // 将初始化的类的实例给CI超级句柄
874 $CI =& get_instance();
875 if ($config !== NULL)
876 {
877 $CI->$classvar = new $name($config);
878 }
879 else
880 {
881 $CI->$classvar = new $name;
882 }
883 }
884
885 // --------------------------------------------------------------------
886
887 /**
888 * 自动加载器
889 *
890 * autoload.php配置的自动加载文件有：
891 * | 1. Packages
892 | 2. Libraries
893 | 3. Helper files
894 | 4. Custom config files
895 | 5. Language files
896 | 6. Models
897 */
898 private function _ci_autoloader()
899 {
900 if (defined(‘ENVIRONMENT‘) AND file_exists(APPPATH.‘config/‘.ENVIRONMENT.‘/autoload.php‘))
901 {
902 include(APPPATH.‘config/‘.ENVIRONMENT.‘/autoload.php‘);
903 }
904 else
905 {
906 include(APPPATH.‘config/autoload.php‘);
907 }
908
909 if ( ! isset($autoload))
910 {
911 return FALSE;
912 }
913
914 // 自动加载packages,也就是将package_path加入到library，model，helper，config
915 if (isset($autoload[‘packages‘]))
916 {
917 foreach ($autoload[‘packages‘] as $package_path)
918 {
919 $this->add_package_path($package_path);
920 }
921 }
922
923 // 加载config文件
924 if (count($autoload[‘config‘]) > 0)
925 {
926 $CI =& get_instance();
927 foreach ($autoload[‘config‘] as $key => $val)
928 {
929 $CI->config->load($val);
930 }
931 }
932
933 // 加载helper和language
934 foreach (array(‘helper‘, ‘language‘) as $type)
935 {
936 if (isset($autoload[$type]) AND count($autoload[$type]) > 0)
937 {
938 $this->$type($autoload[$type]);
939 }
940 }
941
942 // 这个好像是为了兼容以前版本的
943 if ( ! isset($autoload[‘libraries‘]) AND isset($autoload[‘core‘]))
944 {
945 $autoload[‘libraries‘] = $autoload[‘core‘];
946 }
947
948 // 加载libraries
949 if (isset($autoload[‘libraries‘]) AND count($autoload[‘libraries‘]) > 0)
950 {
951 // 加载db
952 if (in_array(‘database‘, $autoload[‘libraries‘]))
953 {
954 $this->database();
955 $autoload[‘libraries‘] = array_diff($autoload[‘libraries‘], array(‘database‘));
956 }
957
958 // 加载所有其他libraries
959 foreach ($autoload[‘libraries‘] as $item)
960 {
961 $this->library($item);
962 }
963 }
964
965 // Autoload models
966 if (isset($autoload[‘model‘]))
967 {
968 $this->model($autoload[‘model‘]);
969 }
970 }
971
972 // --------------------------------------------------------------------
973
974 /**
975 * 返回由对象属性组成的关联数组
976 */
977 protected function _ci_object_to_array($object)
978 {
979 return (is_object($object)) ? get_object_vars($object) : $object;
980 }
981
982 // --------------------------------------------------------------------
983
984 /**
985 * 获取CI某个组件的实例
986 */
987 protected function &_ci_get_component($component)
988 {
989 $CI =& get_instance();
990 return $CI->$component;
991 }
992
993 // --------------------------------------------------------------------
994
995 /**
996 * 处理文件名，这个函数主要是返回正确文件名
997 */
998 protected function _ci_prep_filename($filename, $extension)
999 {
1000 if ( ! is_array($filename))
1001 {
1002 return array(strtolower(str_replace(‘.php‘, ‘‘, str_replace($extension, ‘‘, $filename)).$extension));
1003 }
1004 else
1005 {
1006 foreach ($filename as $key => $val)
1007 {
1008 $filename[$key] = strtolower(str_replace(‘.php‘, ‘‘, str_replace($extension, ‘‘, $val)).$extension);
1009 }
1010
1011 return $filename;
1012 }
1013 }
1014 }
时间： 2024-10-07 03:20:50