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Differences Between: [Versions 310 and 311] [Versions 311 and 403] [Versions 39 and 311]

   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   * Content type manager class
  19   *
  20   * @package    core_contentbank
  21   * @copyright  2020 Amaia Anabitarte <amaia@moodle.com>
  22   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   */
  24  
  25  namespace core_contentbank;
  26  
  27  use core\event\contentbank_content_created;
  28  use core\event\contentbank_content_deleted;
  29  use core\event\contentbank_content_viewed;
  30  use stored_file;
  31  use Exception;
  32  use moodle_url;
  33  
  34  /**
  35   * Content type manager class
  36   *
  37   * @package    core_contentbank
  38   * @copyright  2020 Amaia Anabitarte <amaia@moodle.com>
  39   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  40   */
  41  abstract class contenttype {
  42  
  43      /** @var string Constant representing whether the plugin implements uploading feature */
  44      const CAN_UPLOAD = 'upload';
  45  
  46      /** @var string Constant representing whether the plugin implements edition feature */
  47      const CAN_EDIT = 'edit';
  48  
  49      /**
  50       * @var string Constant representing whether the plugin implements download feature
  51       * @since  Moodle 3.10
  52       */
  53      const CAN_DOWNLOAD = 'download';
  54  
  55      /** @var \context This contenttype's context. **/
  56      protected $context = null;
  57  
  58      /**
  59       * Content type constructor
  60       *
  61       * @param \context $context Optional context to check (default null)
  62       */
  63      public function __construct(\context $context = null) {
  64          if (empty($context)) {
  65              $context = \context_system::instance();
  66          }
  67          $this->context = $context;
  68      }
  69  
  70      /**
  71       * Fills content_bank table with appropiate information.
  72       *
  73       * @throws dml_exception A DML specific exception is thrown for any creation error.
  74       * @param \stdClass $record An optional content record compatible object (default null)
  75       * @return content  Object with content bank information.
  76       */
  77      public function create_content(\stdClass $record = null): content {
  78          global $USER, $DB, $CFG;
  79  
  80          $entry = new \stdClass();
  81          if (isset($record->visibility)) {
  82              $entry->visibility = $record->visibility;
  83          } else {
  84              $usercreated = $record->usercreated ?? $USER->id;
  85              $entry->visibility = get_user_preferences('core_contentbank_visibility',
  86                  $CFG->defaultpreference_core_contentbank_visibility, $usercreated);
  87          }
  88          $entry->contenttype = $this->get_contenttype_name();
  89          $entry->contextid = $this->context->id;
  90          $entry->name = $record->name ?? '';
  91          $entry->usercreated = $record->usercreated ?? $USER->id;
  92          $entry->timecreated = time();
  93          $entry->usermodified = $entry->usercreated;
  94          $entry->timemodified = $entry->timecreated;
  95          $entry->configdata = $record->configdata ?? '';
  96          $entry->instanceid = $record->instanceid ?? 0;
  97          $entry->id = $DB->insert_record('contentbank_content', $entry);
  98          $classname = '\\'.$entry->contenttype.'\\content';
  99          $content = new $classname($entry);
 100          // Trigger an event for creating the content.
 101          $event = contentbank_content_created::create_from_record($content->get_content());
 102          $event->trigger();
 103          return $content;
 104      }
 105  
 106      /**
 107       * Create a new content from an uploaded file.
 108       *
 109       * @throws file_exception If file operations fail
 110       * @throws dml_exception if the content creation fails
 111       * @param stored_file $file the uploaded file
 112       * @param \stdClass|null $record an optional content record
 113       * @return content  Object with content bank information.
 114       */
 115      public function upload_content(stored_file $file, \stdClass $record = null): content {
 116          if (empty($record)) {
 117              $record = new \stdClass();
 118              $record->name = $file->get_filename();
 119          }
 120          $content = $this->create_content($record);
 121          try {
 122              $content->import_file($file);
 123          } catch (Exception $e) {
 124              $this->delete_content($content);
 125              throw $e;
 126          }
 127  
 128          return $content;
 129      }
 130  
 131      /**
 132       * Replace a content using an uploaded file.
 133       *
 134       * @throws file_exception If file operations fail
 135       * @throws dml_exception if the content creation fails
 136       * @param stored_file $file the uploaded file
 137       * @param content $content the original content record
 138       * @return content Object with the updated content bank information.
 139       */
 140      public function replace_content(stored_file $file, content $content): content {
 141          $content->import_file($file);
 142          $content->update_content();
 143          return $content;
 144      }
 145  
 146      /**
 147       * Delete this content from the content_bank.
 148       * This method can be overwritten by the plugins if they need to delete specific information.
 149       *
 150       * @param  content $content The content to delete.
 151       * @return boolean true if the content has been deleted; false otherwise.
 152       */
 153      public function delete_content(content $content): bool {
 154          global $DB;
 155  
 156          // Delete the file if it exists.
 157          if ($file = $content->get_file()) {
 158              $file->delete();
 159          }
 160  
 161          // Delete the contentbank DB entry.
 162          $result = $DB->delete_records('contentbank_content', ['id' => $content->get_id()]);
 163          if ($result) {
 164              // Trigger an event for deleting this content.
 165              $record = $content->get_content();
 166              $event = contentbank_content_deleted::create([
 167                  'objectid' => $content->get_id(),
 168                  'relateduserid' => $record->usercreated,
 169                  'context' => \context::instance_by_id($record->contextid),
 170                  'other' => [
 171                      'contenttype' => $content->get_content_type(),
 172                      'name' => $content->get_name()
 173                  ]
 174              ]);
 175              $event->add_record_snapshot('contentbank_content', $record);
 176              $event->trigger();
 177          }
 178          return $result;
 179      }
 180  
 181      /**
 182       * Rename this content from the content_bank.
 183       * This method can be overwritten by the plugins if they need to change some other specific information.
 184       *
 185       * @param  content $content The content to rename.
 186       * @param  string $name  The name of the content.
 187       * @return boolean true if the content has been renamed; false otherwise.
 188       */
 189      public function rename_content(content $content, string $name): bool {
 190          return $content->set_name($name);
 191      }
 192  
 193      /**
 194       * Move content to another context.
 195       * This method can be overwritten by the plugins if they need to change some other specific information.
 196       *
 197       * @param  content $content The content to rename.
 198       * @param  \context $context  The new context.
 199       * @return boolean true if the content has been renamed; false otherwise.
 200       */
 201      public function move_content(content $content, \context $context): bool {
 202          return $content->set_contextid($context->id);
 203      }
 204  
 205      /**
 206       * Returns the contenttype name of this content.
 207       *
 208       * @return string   Content type of the current instance
 209       */
 210      public function get_contenttype_name(): string {
 211          $classname = get_class($this);
 212          $contenttype = explode('\\', $classname);
 213          return array_shift($contenttype);
 214      }
 215  
 216      /**
 217       * Returns the plugin name of the current instance.
 218       *
 219       * @return string   Plugin name of the current instance
 220       */
 221      public function get_plugin_name(): string {
 222          $contenttype = $this->get_contenttype_name();
 223          $plugin = explode('_', $contenttype);
 224          return array_pop($plugin);
 225      }
 226  
 227      /**
 228       * Returns the URL where the content will be visualized.
 229       *
 230       * @param  content $content The content to be displayed.
 231       * @return string           URL where to visualize the given content.
 232       */
 233      public function get_view_url(content $content): string {
 234          return new moodle_url('/contentbank/view.php', ['id' => $content->get_id()]);
 235      }
 236  
 237      /**
 238       * Returns the HTML content to add to view.php visualizer.
 239       *
 240       * @param  content $content The content to be displayed.
 241       * @return string           HTML code to include in view.php.
 242       */
 243      public function get_view_content(content $content): string {
 244          // Trigger an event for viewing this content.
 245          $event = contentbank_content_viewed::create_from_record($content->get_content());
 246          $event->trigger();
 247  
 248          return '';
 249      }
 250  
 251      /**
 252       * Returns the URL to download the content.
 253       *
 254       * @since  Moodle 3.10
 255       * @param  content $content The content to be downloaded.
 256       * @return string           URL with the content to download.
 257       */
 258      public function get_download_url(content $content): string {
 259          $downloadurl = '';
 260          $file = $content->get_file();
 261          if (!empty($file)) {
 262              $url = \moodle_url::make_pluginfile_url(
 263                  $file->get_contextid(),
 264                  $file->get_component(),
 265                  $file->get_filearea(),
 266                  $file->get_itemid(),
 267                  $file->get_filepath(),
 268                  $file->get_filename()
 269              );
 270              $downloadurl = $url->out(false);
 271          }
 272  
 273          return $downloadurl;
 274      }
 275  
 276      /**
 277       * Returns the HTML code to render the icon for content bank contents.
 278       *
 279       * @param  content $content The content to be displayed.
 280       * @return string               HTML code to render the icon
 281       */
 282      public function get_icon(content $content): string {
 283          global $OUTPUT;
 284          return $OUTPUT->image_url('f/unknown-64', 'moodle')->out(false);
 285      }
 286  
 287      /**
 288       * Returns user has access capability for the main content bank and the content itself (base on is_access_allowed from plugin).
 289       *
 290       * @return bool     True if content could be accessed. False otherwise.
 291       */
 292      final public function can_access(): bool {
 293          $classname = 'contenttype/'.$this->get_plugin_name();
 294          $capability = $classname.":access";
 295          $hascapabilities = has_capability('moodle/contentbank:access', $this->context)
 296              && has_capability($capability, $this->context);
 297          return $hascapabilities && $this->is_access_allowed();
 298      }
 299  
 300      /**
 301       * Returns user has access capability for the content itself.
 302       *
 303       * @return bool     True if content could be accessed. False otherwise.
 304       */
 305      protected function is_access_allowed(): bool {
 306          // Plugins can overwrite this function to add any check they need.
 307          return true;
 308      }
 309  
 310      /**
 311       * Returns the user has permission to upload new content.
 312       *
 313       * @return bool     True if content could be uploaded. False otherwise.
 314       */
 315      final public function can_upload(): bool {
 316          if (!$this->is_feature_supported(self::CAN_UPLOAD)) {
 317              return false;
 318          }
 319          if (!$this->can_access()) {
 320              return false;
 321          }
 322  
 323          $classname = 'contenttype/'.$this->get_plugin_name();
 324          $uploadcap = $classname.':upload';
 325          $hascapabilities = has_capability('moodle/contentbank:upload', $this->context)
 326              && has_capability($uploadcap, $this->context);
 327          return $hascapabilities && $this->is_upload_allowed();
 328      }
 329  
 330      /**
 331       * Returns plugin allows uploading.
 332       *
 333       * @return bool     True if plugin allows uploading. False otherwise.
 334       */
 335      protected function is_upload_allowed(): bool {
 336          // Plugins can overwrite this function to add any check they need.
 337          return true;
 338      }
 339  
 340      /**
 341       * Check if the user can delete this content.
 342       *
 343       * @param  content $content The content to be deleted.
 344       * @return bool True if content could be uploaded. False otherwise.
 345       */
 346      final public function can_delete(content $content): bool {
 347          global $USER;
 348  
 349          if ($this->context->id != $content->get_content()->contextid) {
 350              // The content has to have exactly the same context as this contenttype.
 351              return false;
 352          }
 353  
 354          $hascapability = has_capability('moodle/contentbank:deleteanycontent', $this->context);
 355          if ($content->get_content()->usercreated == $USER->id) {
 356              // This content has been created by the current user; check if she can delete her content.
 357              $hascapability = $hascapability || has_capability('moodle/contentbank:deleteowncontent', $this->context);
 358          }
 359  
 360          return $hascapability && $this->is_delete_allowed($content);
 361      }
 362  
 363      /**
 364       * Returns if content allows deleting.
 365       *
 366       * @param  content $content The content to be deleted.
 367       * @return bool True if content allows uploading. False otherwise.
 368       */
 369      protected function is_delete_allowed(content $content): bool {
 370          // Plugins can overwrite this function to add any check they need.
 371          return true;
 372      }
 373  
 374      /**
 375       * Check if the user can managed this content.
 376       *
 377       * @param  content $content The content to be managed.
 378       * @return bool     True if content could be managed. False otherwise.
 379       */
 380      public final function can_manage(content $content): bool {
 381          global $USER;
 382  
 383          if ($this->context->id != $content->get_content()->contextid) {
 384              // The content has to have exactly the same context as this contenttype.
 385              return false;
 386          }
 387  
 388          // Check main contentbank management permission.
 389          $hascapability = has_capability('moodle/contentbank:manageanycontent', $this->context);
 390          if ($content->get_content()->usercreated == $USER->id) {
 391              // This content has been created by the current user; check if they can manage their content.
 392              $hascapability = $hascapability || has_capability('moodle/contentbank:manageowncontent', $this->context);
 393          }
 394  
 395          return $hascapability && $this->is_manage_allowed($content);
 396      }
 397  
 398      /**
 399       * Returns if content allows managing.
 400       *
 401       * @param  content $content The content to be managed.
 402       * @return bool True if content allows uploading. False otherwise.
 403       */
 404      protected function is_manage_allowed(content $content): bool {
 405          // Plugins can overwrite this function to add any check they need.
 406          return true;
 407      }
 408  
 409      /**
 410       * Returns whether or not the user has permission to use the editor.
 411       * This function will be called with the content to be edited as parameter,
 412       * or null when is checking permission to create a new content using the editor.
 413       *
 414       * @param  content $content The content to be edited or null when creating a new content.
 415       * @return bool     True if the user can edit content. False otherwise.
 416       */
 417      final public function can_edit(?content $content = null): bool {
 418          if (!$this->is_feature_supported(self::CAN_EDIT)) {
 419              return false;
 420          }
 421  
 422          if (!$this->can_access()) {
 423              return false;
 424          }
 425  
 426          if (!is_null($content) && !$this->can_manage($content)) {
 427              return false;
 428          }
 429  
 430          $classname = 'contenttype/'.$this->get_plugin_name();
 431  
 432          $editioncap = $classname.':useeditor';
 433          $hascapabilities = has_all_capabilities(['moodle/contentbank:useeditor', $editioncap], $this->context);
 434          return $hascapabilities && $this->is_edit_allowed($content);
 435      }
 436  
 437      /**
 438       * Returns plugin allows edition.
 439       *
 440       * @param  content $content The content to be edited.
 441       * @return bool     True if plugin allows edition. False otherwise.
 442       */
 443      protected function is_edit_allowed(?content $content): bool {
 444          // Plugins can overwrite this function to add any check they need.
 445          return true;
 446      }
 447  
 448      /**
 449       * Returns whether or not the user has permission to download the content.
 450       *
 451       * @since  Moodle 3.10
 452       * @param  content $content The content to be downloaded.
 453       * @return bool    True if the user can download the content. False otherwise.
 454       */
 455      final public function can_download(content $content): bool {
 456          if (!$this->is_feature_supported(self::CAN_DOWNLOAD)) {
 457              return false;
 458          }
 459  
 460          if (!$this->can_access()) {
 461              return false;
 462          }
 463  
 464          $hascapability = has_capability('moodle/contentbank:downloadcontent', $this->context);
 465          return $hascapability && $this->is_download_allowed($content);
 466      }
 467  
 468      /**
 469       * Returns plugin allows downloading.
 470       *
 471       * @since  Moodle 3.10
 472       * @param  content $content The content to be downloaed.
 473       * @return bool    True if plugin allows downloading. False otherwise.
 474       */
 475      protected function is_download_allowed(content $content): bool {
 476          // Plugins can overwrite this function to add any check they need.
 477          return true;
 478      }
 479  
 480      /**
 481       * Returns the plugin supports the feature.
 482       *
 483       * @param string $feature Feature code e.g CAN_UPLOAD
 484       * @return bool     True if content could be uploaded. False otherwise.
 485       */
 486      final public function is_feature_supported(string $feature): bool {
 487          return in_array($feature, $this->get_implemented_features());
 488      }
 489  
 490      /**
 491       * Return an array of implemented features by the plugins.
 492       *
 493       * @return array
 494       */
 495      abstract protected function get_implemented_features(): array;
 496  
 497      /**
 498       * Return an array of extensions the plugins could manage.
 499       *
 500       * @return array
 501       */
 502      abstract public function get_manageable_extensions(): array;
 503  
 504      /**
 505       * Returns the list of different types of the given content type.
 506       *
 507       * A content type can have one or more options for creating content. This method will report all of them or only the content
 508       * type itself if it has no other options.
 509       *
 510       * @return array An object for each type:
 511       *     - string typename: descriptive name of the type.
 512       *     - string typeeditorparams: params required by this content type editor.
 513       *     - url typeicon: this type icon.
 514       */
 515      abstract public function get_contenttype_types(): array;
 516  }