lib/filebrowser/file_info_context_coursecat.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17
  18 /**
  19  * Utility class for browsing of curse category files.
  20  *
  21  * @package    core_files
  22  * @copyright  2008 Petr Skoda (http://skodak.org)
  23  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25
  26 defined('MOODLE_INTERNAL') || die();
  27
  28 /**
  29  * Represents a course category context in the tree navigated by {@link file_browser}.
  30  *
  31  * @package    core_files
  32  * @copyright  2008 Petr Skoda (http://skodak.org)
  33  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  34  */
  35 class file_info_context_coursecat extends file_info {
  36     /** @var stdClass Category object */
  37     protected $category;
  38
  39     /**
  40      * Constructor
  41      *
  42      * @param file_browser $browser file browser instance
  43      * @param stdClass $context context object
  44      * @param stdClass $category category object
  45      */
  46     public function __construct($browser, $context, $category) {
  47         parent::__construct($browser, $context);
  48         $this->category = $category;
  49     }
  50
  51     /**
  52      * Return information about this specific context level
  53      *
  54      * @param string $component component
  55      * @param string $filearea file area
  56      * @param int $itemid item ID
  57      * @param string $filepath file path
  58      * @param string $filename file name
  59      * @return fileinfo|null
  60      */
  61     public function get_file_info($component, $filearea, $itemid, $filepath, $filename) {
  62         global $DB;
  63
  64         if (!core_course_category::can_view_category($this->category)) {
  65             if (empty($component)) {
  66                 // we can not list the category contents, so try parent, or top system
  67                 if ($this->category->parent and $pc = $DB->get_record('course_categories', array('id'=>$this->category->parent))) {
  68                     $parent = context_coursecat::instance($pc->id, IGNORE_MISSING);
  69                     return $this->browser->get_file_info($parent);
  70                 } else {
  71                     return $this->browser->get_file_info();
  72                 }
  73             }
  74             return null;
  75         }
  76
  77         if (empty($component)) {
  78             return $this;
  79         }
  80
  81         $methodname = "get_area_{$component}_{$filearea}";
  82         if (method_exists($this, $methodname)) {
  83             return $this->$methodname($itemid, $filepath, $filename);
  84         }
  85
  86         return null;
  87     }
  88
  89     /**
  90      * Return a file from course category description area
  91      *
  92      * @param int $itemid item ID
  93      * @param string $filepath file path
  94      * @param string $filename file name
  95      * @return fileinfo|null
  96      */
  97     protected function get_area_coursecat_description($itemid, $filepath, $filename) {
  98         global $CFG;
  99
 100         if (!$this->category->id) {
 101             // No coursecat description area for "system".
 102             return null;
 103         }
 104         if (!core_course_category::can_view_category($this->category)) {
 105             return null;
 106         }
 107         if (!has_capability('moodle/category:manage', $this->context)) {
 108             return null;
 109         }
 110
 111         if (is_null($itemid)) {
 112             return $this;
 113         }
 114
 115         $fs = get_file_storage();
 116
 117         $filepath = is_null($filepath) ? '/' : $filepath;
 118         $filename = is_null($filename) ? '.' : $filename;
 119         $urlbase = $CFG->wwwroot.'/pluginfile.php';
 120         if (!$storedfile = $fs->get_file($this->context->id, 'coursecat', 'description', 0, $filepath, $filename)) {
 121             if ($filepath === '/' and $filename === '.') {
 122                 $storedfile = new virtual_root_file($this->context->id, 'coursecat', 'description', 0);
 123             } else {
 124                 // not found
 125                 return null;
 126             }
 127         }
 128
 129         return new file_info_stored($this->browser, $this->context, $storedfile, $urlbase, get_string('areacategoryintro', 'repository'), false, true, true, false);
 130     }
 131
 132     /**
 133      * Returns localised visible name.
 134      *
 135      * @return string
 136      */
 137     public function get_visible_name() {
 138         return format_string($this->category->name, true, array('context'=>$this->context));
 139     }
 140
 141     /**
 142      * Whether or not new files or directories can be added
 143      *
 144      * @return bool
 145      */
 146     public function is_writable() {
 147         return false;
 148     }
 149
 150     /**
 151      * Whether or not this is a directory
 152      *
 153      * @return bool
 154      */
 155     public function is_directory() {
 156         return true;
 157     }
 158
 159     /**
 160      * Returns list of children.
 161      *
 162      * @return array of file_info instances
 163      */
 164     public function get_children() {
 165         $children = array();
 166
 167         if ($child = $this->get_area_coursecat_description(0, '/', '.')) {
 168             $children[] = $child;
 169         }
 170
 171         list($coursecats, $hiddencats) = $this->get_categories();
 172         foreach ($coursecats as $category) {
 173             $context = context_coursecat::instance($category->id);
 174             $children[] = new self($this->browser, $context, $category);
 175         }
 176
 177         $courses = $this->get_courses($hiddencats);
 178         foreach ($courses as $course) {
 179             $children[] = $this->get_child_course($course);
 180         }
 181
 182         return array_filter($children);
 183     }
 184
 185     /**
 186      * List of courses in this category and in hidden subcategories
 187      *
 188      * @param array $hiddencats list of categories that are hidden from current user and returned by {@link get_categories()}
 189      * @return array list of courses
 190      */
 191     protected function get_courses($hiddencats) {
 192         global $DB, $CFG;
 193         require_once($CFG->libdir.'/modinfolib.php');
 194
 195         $params = array('category' => $this->category->id, 'contextlevel' => CONTEXT_COURSE);
 196         $sql = 'c.category = :category';
 197
 198         foreach ($hiddencats as $category) {
 199             $catcontext = context_coursecat::instance($category->id);
 200             $sql .= ' OR ' . $DB->sql_like('ctx.path', ':path' . $category->id);
 201             $params['path' . $category->id] = $catcontext->path . '/%';
 202         }
 203
 204         // Let's retrieve only minimum number of fields from course table -
 205         // what is needed to check access or call get_fast_modinfo().
 206         $coursefields = array_merge(['id', 'visible'], course_modinfo::$cachedfields);
 207         $fields = 'c.' . join(',c.', $coursefields) . ', ' .
 208             context_helper::get_preload_record_columns_sql('ctx');
 209         return $DB->get_records_sql('SELECT ' . $fields . ' FROM {course} c
 210                 JOIN {context} ctx ON (ctx.instanceid = c.id AND ctx.contextlevel = :contextlevel)
 211                 WHERE ('.$sql.') ORDER BY c.sortorder', $params);
 212     }
 213
 214     /**
 215      * Finds accessible and non-accessible direct subcategories
 216      *
 217      * @return array [$coursecats, $hiddencats] - child categories that are visible to the current user and not visible
 218      */
 219     protected function get_categories() {
 220         global $DB;
 221         $fields = 'c.*, ' . context_helper::get_preload_record_columns_sql('ctx');
 222         $coursecats = $DB->get_records_sql('SELECT ' . $fields . ' FROM {course_categories} c
 223                 LEFT JOIN {context} ctx ON (ctx.instanceid = c.id AND ctx.contextlevel = :contextlevel)
 224                 WHERE c.parent = :parent ORDER BY c.sortorder',
 225             array('parent' => $this->category->id, 'contextlevel' => CONTEXT_COURSECAT));
 226
 227         $hiddencats = [];
 228
 229         foreach ($coursecats as $id => &$category) {
 230             context_helper::preload_from_record($category);
 231             if (!core_course_category::can_view_category($category)) {
 232                 $hiddencats[$id] = $coursecats[$id];
 233                 unset($coursecats[$id]);
 234             }
 235         }
 236         return [$coursecats, $hiddencats];
 237     }
 238
 239     /**
 240      * Returns the file info element for a given course or null if course is not accessible
 241      *
 242      * @param stdClass $course may contain context fields for preloading
 243      * @return file_info_context_course|null
 244      */
 245     protected function get_child_course($course) {
 246         context_helper::preload_from_record($course);
 247         $context = context_course::instance($course->id);
 248         $child = new file_info_context_course($this->browser, $context, $course);
 249         return $child->get_file_info(null, null, null, null, null);
 250     }
 251
 252     /**
 253      * Returns the number of children which are either files matching the specified extensions
 254      * or folders containing at least one such file.
 255      *
 256      * @param string|array $extensions, for example '*' or array('.gif','.jpg')
 257      * @param int $limit stop counting after at least $limit non-empty children are found
 258      * @return int
 259      */
 260     public function count_non_empty_children($extensions = '*', $limit = 1) {
 261         $cnt = 0;
 262         if ($child = $this->get_area_coursecat_description(0, '/', '.')) {
 263             $cnt += $child->count_non_empty_children($extensions) ? 1 : 0;
 264             if ($cnt >= $limit) {
 265                 return $cnt;
 266             }
 267         }
 268
 269         list($coursecats, $hiddencats) = $this->get_categories();
 270         foreach ($coursecats as $category) {
 271             $context = context_coursecat::instance($category->id);
 272             $child = new file_info_context_coursecat($this->browser, $context, $category);
 273             $cnt += $child->count_non_empty_children($extensions) ? 1 : 0;
 274             if ($cnt >= $limit) {
 275                 return $cnt;
 276             }
 277         }
 278
 279         $courses = $this->get_courses($hiddencats);
 280         foreach ($courses as $course) {
 281             if ($child = $this->get_child_course($course)) {
 282                 $cnt += $child->count_non_empty_children($extensions) ? 1 : 0;
 283                 if ($cnt >= $limit) {
 284                     return $cnt;
 285                 }
 286             }
 287         }
 288
 289         return $cnt;
 290     }
 291
 292     /**
 293      * Returns parent file_info instance
 294      *
 295      * @return file_info|null fileinfo instance or null for root directory
 296      */
 297     public function get_parent() {
 298         $parent = $this->context->get_parent_context();
 299         return $this->browser->get_file_info($parent);
 300     }
 301 }