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 }