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   1  <?php
   2  
   3  // This file is part of Moodle - http://moodle.org/
   4  //
   5  // Moodle is free software: you can redistribute it and/or modify
   6  // it under the terms of the GNU General Public License as published by
   7  // the Free Software Foundation, either version 3 of the License, or
   8  // (at your option) any later version.
   9  //
  10  // Moodle is distributed in the hope that it will be useful,
  11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  // GNU General Public License for more details.
  14  //
  15  // You should have received a copy of the GNU General Public License
  16  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17  
  18  /**
  19   * This file contains the backup user interface class
  20   *
  21   * @package   moodlecore
  22   * @copyright 2010 Sam Hemelryk
  23   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24   */
  25  
  26  /**
  27   * This is the backup user interface class
  28   *
  29   * The backup user interface class manages the user interface and backup for
  30   * Moodle.
  31   *
  32   * @copyright 2010 Sam Hemelryk
  33   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  34   */
  35  abstract class base_ui {
  36      /**
  37       * The progress of this instance of the backup ui class
  38       */
  39      const PROGRESS_INTIAL = 0;
  40      const PROGRESS_PROCESSED = 1;
  41      const PROGRESS_SAVED = 2;
  42      const PROGRESS_EXECUTED = 3;
  43      /**
  44       * The controller
  45       * @var backup_controller|restore_controller
  46       */
  47      protected $controller;
  48      /**
  49       * The current stage
  50       * @var base_ui_stage
  51       */
  52      protected $stage;
  53      /**
  54       * The current progress of the UI
  55       * @var int One of self::PROGRESS_*
  56       */
  57      protected $progress;
  58      /**
  59       * The number of changes made by dependency enforcement
  60       * @var int
  61       */
  62      protected $dependencychanges = 0;
  63  
  64      /**
  65       * Yay for constructors
  66       * @param backup_controller $controller
  67       */
  68      public function __construct($controller, array $params=null) {
  69          $this->controller = $controller;
  70          $this->progress = self::PROGRESS_INTIAL;
  71          $this->stage = $this->initialise_stage(null, $params);
  72          // Process UI event before to be safe
  73          $this->controller->process_ui_event();
  74      }
  75      /**
  76       * Destorys the backup controller and the loaded stage.
  77       */
  78      public function destroy() {
  79  
  80          if ($this->controller) {
  81              $this->controller->destroy();
  82          }
  83          unset($this->stage);
  84  
  85      }
  86      /**
  87       * Intialises what ever stage is requested. If none are requested we check
  88       * params for 'stage' and default to initial
  89       *
  90       * @param int|null $stage The desired stage to intialise or null for the default
  91       * @return base_ui_stage
  92       */
  93      abstract protected function initialise_stage($stage = null, array $params=null);
  94      /**
  95       * This processes the current stage of the backup
  96       * @return bool
  97       */
  98      public function process() {
  99          if ($this->progress >= self::PROGRESS_PROCESSED) {
 100              throw new backup_ui_exception('backupuialreadyprocessed');
 101          }
 102          $this->progress = self::PROGRESS_PROCESSED;
 103  
 104          if (optional_param('previous', false, PARAM_BOOL) && $this->stage->get_stage() > $this->get_first_stage_id()) {
 105              $this->stage = $this->initialise_stage($this->stage->get_prev_stage(), $this->stage->get_params());
 106              return false;
 107          }
 108  
 109          // Process the stage
 110          $processoutcome = $this->stage->process();
 111  
 112          if ($processoutcome !== false) {
 113              $this->stage = $this->initialise_stage($this->stage->get_next_stage(), $this->stage->get_params());
 114          }
 115  
 116          // Process UI event after to check changes are valid
 117          $this->controller->process_ui_event();
 118          return $processoutcome;
 119      }
 120      /**
 121       * Saves the backup controller.
 122       *
 123       * Once this has been called nothing else can be changed in the controller.
 124       *
 125       * @return bool
 126       */
 127      public function save_controller() {
 128          if ($this->progress >= self::PROGRESS_SAVED) {
 129              throw new base_ui_exception('backupuialreadysaved');
 130          }
 131          $this->progress = self::PROGRESS_SAVED;
 132          // First enforce dependencies
 133          $this->enforce_dependencies();
 134          // Process UI event after to check any changes are valid
 135          $this->controller->process_ui_event();
 136          // Save the controller
 137          $this->controller->save_controller();
 138          return true;
 139      }
 140      /**
 141       * Displays the UI for the backup!
 142       *
 143       * @param core_backup_renderer $renderer
 144       * @return string HTML code to echo
 145       */
 146      public function display(core_backup_renderer $renderer) {
 147          if ($this->progress < self::PROGRESS_SAVED) {
 148              throw new base_ui_exception('backupsavebeforedisplay');
 149          }
 150          return $this->stage->display($renderer);
 151      }
 152      /**
 153       * Gets all backup tasks from the controller
 154       * @return array Array of backup_task
 155       */
 156      public function get_tasks() {
 157          $plan = $this->controller->get_plan();
 158          $tasks = $plan->get_tasks();
 159          return $tasks;
 160      }
 161      /**
 162       * Gets the stage we are on
 163       * @return int
 164       */
 165      public function get_stage() {
 166          return $this->stage->get_stage();
 167      }
 168      /**
 169       * Gets the name of the stage we are on
 170       * @return string
 171       */
 172      public function get_stage_name() {
 173          return $this->stage->get_name();
 174      }
 175      /**
 176       * Gets the backup id from the controller
 177       * @return string
 178       */
 179      abstract public function get_uniqueid();
 180      /**
 181       * Executes the backup plan
 182       * @return bool
 183       */
 184      abstract public function execute();
 185      /**
 186       * Enforces dependencies on all settings. Call before save
 187       * @return bool True if dependencies were enforced and changes were made
 188       */
 189      protected function enforce_dependencies() {
 190          // Get the plan
 191          $plan = $this->controller->get_plan();
 192          // Get the tasks as a var so we can iterate by reference
 193          $tasks = $plan->get_tasks();
 194          $changes = 0;
 195          foreach ($tasks as &$task) {
 196              // Store as a var so we can iterate by reference
 197              $settings = $task->get_settings();
 198              foreach ($settings as &$setting) {
 199                  // Get all dependencies for iteration by reference
 200                  $dependencies = $setting->get_dependencies();
 201                  foreach ($dependencies as &$dependency) {
 202                      // Enforce each dependency
 203                      if ($dependency->enforce()) {
 204                          $changes++;
 205                      }
 206                  }
 207              }
 208          }
 209          // Store the number of settings that changed through enforcement
 210          $this->dependencychanges = $changes;
 211          return ($changes>0);
 212      }
 213      /**
 214       * Returns true if enforce_dependencies changed any settings
 215       * @return bool
 216       */
 217      public function enforce_changed_dependencies() {
 218          return ($this->dependencychanges > 0);
 219      }
 220      /**
 221       * Loads the backup controller if we are tracking one
 222       * @return backup_controller|false
 223       */
 224      public static function load_controller($uniqueid=false) {
 225          throw new coding_exception('load_controller() method needs to be overridden in each subclass of base_ui');
 226      }
 227  
 228      /**
 229       * Cancels the current backup/restore and redirects the user back to the relevant place
 230       */
 231      public function cancel_process() {
 232          global $PAGE;
 233          // Determine the appropriate URL to redirect the user to
 234          if ($PAGE->context->contextlevel == CONTEXT_MODULE && $PAGE->cm !== null) {
 235              $relevanturl = new moodle_url('/mod/'.$PAGE->cm->modname.'/view.php', array('id'=>$PAGE->cm->id));
 236          } else {
 237              $relevanturl = new moodle_url('/course/view.php', array('id'=>$PAGE->course->id));
 238          }
 239          redirect($relevanturl);
 240      }
 241  
 242      /**
 243       * Gets an array of progress bar items that can be displayed through the backup renderer.
 244       * @return array Array of items for the progress bar
 245       */
 246      abstract public function get_progress_bar();
 247      /**
 248       * Gets the format for the backup
 249       * @return int
 250       */
 251      public function get_format() {
 252          return $this->controller->get_format();
 253      }
 254      /**
 255       * Gets the type of the backup
 256       * @return int
 257       */
 258      public function get_type() {
 259          return $this->controller->get_type();
 260      }
 261      public function get_controller() {
 262          return $this->controller;
 263      }
 264      /**
 265       * Gets the ID used in creating the controller. Relates to course/section/cm
 266       * @return int
 267       */
 268      public function get_controller_id() {
 269          return $this->controller->get_id();
 270      }
 271      /**
 272       * Gets the requested setting
 273       * @param string $name
 274       * @return mixed
 275       */
 276      public function get_setting($name, $default = false) {
 277          try {
 278              return $this->controller->get_plan()->get_setting($name);
 279          } catch (Exception $e) {
 280              debugging('Failed to find the setting: '.$name, DEBUG_DEVELOPER);
 281              return $default;
 282          }
 283      }
 284      /**
 285       * Gets the value for the requested setting
 286       *
 287       * @param string $name
 288       * @return mixed
 289       */
 290      public function get_setting_value($name, $default = false) {
 291          try {
 292              return $this->controller->get_plan()->get_setting($name)->get_value();
 293          } catch (Exception $e) {
 294              debugging('Failed to find the setting: '.$name, DEBUG_DEVELOPER);
 295              return $default;
 296          }
 297      }
 298  
 299      abstract public function get_name();
 300  
 301      abstract public function get_first_stage_id();
 302  }
 303  
 304  /**
 305   * Backup user interface exception. Modelled off the backup_exception class
 306   */
 307  class base_ui_exception extends backup_exception {}