[Summary view]

   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  namespace tool_brickfield\local\tool;
  18  
  19  use tool_brickfield\accessibility;
  20  use tool_brickfield\manager;
  21  
  22  /**
  23   * Class filter.
  24   *
  25   * @package tool_brickfield
  26   * @copyright  2020 onward: Brickfield Education Labs, www.brickfield.ie
  27   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  28   */
  29  class filter {
  30  
  31      /** @var int Possible course id being filtered. */
  32      public $courseid;
  33  
  34      /** @var int Possible category id being filtered. */
  35      public $categoryid;
  36  
  37      /** @var string The tab (page) being accessed. */
  38      public $tab;
  39  
  40      /** @var int The page number if multiple pages. */
  41      public $page;
  42  
  43      /** @var int Number of items per page for multiple pages. */
  44      public $perpage;
  45  
  46      /** @var array Array of filtered course ids if more than one. */
  47      public $courseids;
  48  
  49      /** @var string The url of the page being accessed. */
  50      public $url;
  51  
  52      /** @var string The output target. */
  53      public $target;
  54  
  55      /** @var string Any error message if present. */
  56      protected $errormessage;
  57  
  58      /**
  59       * filter constructor.
  60       * @param int $courseid
  61       * @param int $categoryid
  62       * @param string $tab
  63       * @param int $page
  64       * @param int $perpage
  65       * @param string $url
  66       * @param string $target
  67       */
  68      public function __construct(int $courseid = 0, int $categoryid = 0, string $tab = '',
  69                                  int $page = 0, int $perpage = 0, string $url = '', string $target = '') {
  70          $this->courseid = $courseid;
  71          $this->categoryid = $categoryid;
  72          $this->tab = $tab;
  73          $this->page = $page;
  74          $this->perpage = $perpage;
  75          $this->url = $url;
  76          $this->target = $target;
  77      }
  78  
  79      /**
  80       * Get any course and category sql fragment and parameters and return as an array for this filter. Return false if course
  81       * filters are invalid.
  82       * @param string $alias Optional field alias to prefix on the where condition.
  83       * @param bool $onlycondition Set to true if this is the only condition to be used in the SQL statement.
  84       * @return array|bool
  85       * @throws \coding_exception
  86       * @throws \dml_exception
  87       */
  88      public function get_course_sql(string $alias = '', bool $onlycondition = false) {
  89          global $DB;
  90  
  91          $params = [];
  92          if ($alias != '') {
  93              $alias .= '.';
  94          }
  95          if (!$onlycondition) {
  96              $sql = ' AND (';
  97          } else {
  98              $sql = '(';
  99          }
 100          if ($this->courseid != 0) {
 101              $sql .= $alias . 'courseid = ?)';
 102              $params[] = $this->courseid;
 103          } else if (($this->categoryid != 0) || !empty($this->courseids)) {
 104              if ($this->validate_filters()) {
 105                  list($coursesql, $params) = $DB->get_in_or_equal($this->courseids);
 106                  $sql .= $alias . 'courseid '.$coursesql . ')';
 107              } else {
 108                  $sql = '';
 109              }
 110          } else {
 111              $sql = '';
 112          }
 113          return [$sql, $params];
 114      }
 115  
 116      /**
 117       * Validate the filters. Set an errormessage if invalid. No filters is also valid - in that case using entire system.
 118       * @return bool
 119       * @throws \coding_exception
 120       * @throws \dml_exception
 121       */
 122      public function validate_filters(): bool {
 123          if (!empty($this->courseid)) {
 124              return true;
 125          } else if (!empty($this->categoryid) && empty($this->courseids)) {
 126              $this->courseids = accessibility::get_category_courseids($this->categoryid);
 127              if ($this->courseids === null) {
 128                  $this->errormessage = get_string('invalidcategoryid', manager::PLUGINNAME);
 129                  return false;
 130              } else if (count($this->courseids) == 0) {
 131                  $this->errormessage = get_string('emptycategory', manager::PLUGINNAME, $this->categoryid);
 132                  return false;
 133              }
 134          }
 135          return true;
 136      }
 137  
 138      /**
 139       * Return true if filter has course filter data, and the data is valid. Note that the site uses courseid 1.
 140       * @return bool
 141       * @throws \coding_exception
 142       * @throws \dml_exception
 143       */
 144      public function has_course_filters(): bool {
 145          if ((!empty($this->courseid) && ($this->courseid > 1)) || !empty($this->categoryid) || !empty($this->courseids)) {
 146              return $this->validate_filters();
 147          }
 148          return false;
 149      }
 150  
 151      /**
 152       * Check whether the user has appropriate permissions on the supplied context. Determine the capability to check by the filters
 153       * that are set.
 154       * @param \context|null $context The context being viewed (e.g. system, course category, course).
 155       * @param string $capability An optional capability to check.
 156       * @return bool
 157       * @throws \coding_exception
 158       * @throws \dml_exception
 159       */
 160      public function can_access(\context $context = null, string $capability = ''): bool {
 161          if ($capability == '') {
 162              if ($this->has_course_filters()) {
 163                  $capability = accessibility::get_capability_name('viewcoursetools');
 164              } else {
 165                  $capability = accessibility::get_capability_name('viewsystemtools');
 166              }
 167          }
 168          return $this->has_capability_in_context($capability, $context);
 169      }
 170  
 171      /**
 172       * Check the specified capability against the filter's context, or the specified context with the filter's information.
 173       * @param string $capability
 174       * @param null $context
 175       * @return bool
 176       * @throws \coding_exception
 177       * @throws \dml_exception
 178       */
 179      public function has_capability_in_context(string $capability, \context $context = null): bool {
 180          $coursefiltersvalid = $this->has_course_filters();
 181          if ($context === null) {
 182              // If the filter is using a list of courses ($this->>courseids), use the system context.
 183              if ($coursefiltersvalid && !empty($this->courseid)) {
 184                  if (!empty($this->categoryid)) {
 185                      $context = \context_coursecat::instance($this->categoryid);
 186                  } else {
 187                      $context = \context_course::instance($this->courseid);
 188                  }
 189              } else {
 190                  $context = \context_system::instance();
 191              }
 192          }
 193  
 194          return has_capability($capability, $context);
 195      }
 196  
 197      /**
 198       * Return the error message data.
 199       * @return mixed
 200       */
 201      public function get_errormessage() {
 202          return $this->errormessage;
 203      }
 204  }