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Differences Between: [Versions 310 and 311] [Versions 310 and 400] [Versions 310 and 401] [Versions 310 and 402] [Versions 310 and 403]

   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   * Table filterset.
  19   *
  20   * @package    core
  21   * @category   table
  22   * @copyright  2020 Andrew Nicols <andrew@nicols.co.uk>
  23   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24   */
  25  
  26  declare(strict_types=1);
  27  
  28  namespace core_table\local\filter;
  29  
  30  use InvalidArgumentException;
  31  use JsonSerializable;
  32  use UnexpectedValueException;
  33  use moodle_exception;
  34  
  35  /**
  36   * Class representing a set of filters.
  37   *
  38   * @package    core
  39   * @copyright  2020 Andrew Nicols <andrew@nicols.co.uk>
  40   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  41   */
  42  abstract class filterset implements JsonSerializable {
  43      /** @var in The default filter type (ANY) */
  44      const JOINTYPE_DEFAULT = 1;
  45  
  46      /** @var int None of the following match */
  47      const JOINTYPE_NONE = 0;
  48  
  49      /** @var int Any of the following match */
  50      const JOINTYPE_ANY = 1;
  51  
  52      /** @var int All of the following match */
  53      const JOINTYPE_ALL = 2;
  54  
  55      /** @var int The join type currently in use */
  56      protected $jointype = self::JOINTYPE_DEFAULT;
  57  
  58      /** @var array The list of combined filter types */
  59      protected $filtertypes = null;
  60  
  61      /** @var array The list of active filters */
  62      protected $filters = [];
  63  
  64      /** @var int[] valid join types */
  65      protected $jointypes = [
  66          self::JOINTYPE_NONE,
  67          self::JOINTYPE_ANY,
  68          self::JOINTYPE_ALL,
  69      ];
  70  
  71      /**
  72       * Specify the type of join to employ for the filter.
  73       *
  74       * @param int $jointype The join type to use using one of the supplied constants
  75       * @return self
  76       */
  77      public function set_join_type(int $jointype): self {
  78          if (array_search($jointype, $this->jointypes) === false) {
  79              throw new InvalidArgumentException('Invalid join type specified');
  80          }
  81  
  82          $this->jointype = $jointype;
  83  
  84          return $this;
  85      }
  86  
  87      /**
  88       * Return the currently specified join type.
  89       *
  90       * @return int
  91       */
  92      public function get_join_type(): int {
  93          return $this->jointype;
  94      }
  95  
  96      /**
  97       * Add the specified filter.
  98       *
  99       * @param filter $filter
 100       * @return self
 101       */
 102      public function add_filter(filter $filter): self {
 103          $filtername = $filter->get_name();
 104  
 105          if (array_key_exists($filtername, $this->filters)) {
 106              // This filter already exists.
 107              if ($this->filters[$filtername] === $filter) {
 108                  // This is the same value as already added.
 109                  // Just ignore it.
 110                  return $this;
 111              }
 112  
 113              // This is a different value to last time. Fail as this is not supported.
 114              throw new UnexpectedValueException(
 115                  "A filter of type '{$filtername}' has already been added. Check that you have the correct filter."
 116              );
 117          }
 118  
 119          // Ensure that the filter is both known, and is of the correct type.
 120          $validtypes = $this->get_all_filtertypes();
 121  
 122          if (!array_key_exists($filtername, $validtypes)) {
 123              // Unknown filter.
 124              throw new InvalidArgumentException(
 125                  "The filter '{$filtername}' was not recognised."
 126              );
 127          }
 128  
 129          // Check that the filter is of the correct type.
 130          if (!is_a($filter, $validtypes[$filtername])) {
 131              $actualtype = get_class($filter);
 132              $requiredtype = $validtypes[$filtername];
 133  
 134              throw new InvalidArgumentException(
 135                  "The filter '{$filtername}' was incorrectly specified as a {$actualtype}. It must be a {$requiredtype}."
 136              );
 137          }
 138  
 139          // All good. Add the filter.
 140          $this->filters[$filtername] = $filter;
 141  
 142          return $this;
 143      }
 144  
 145      /**
 146       * Add the specified filter from the supplied params.
 147       *
 148       * @param string $filtername The name of the filter to create
 149       * @param mixed[] ...$args Additional arguments used to create this filter type
 150       * @return self
 151       */
 152      public function add_filter_from_params(string $filtername, ...$args): self {
 153          // Fetch the list of valid filters by name.
 154          $validtypes = $this->get_all_filtertypes();
 155  
 156          if (!array_key_exists($filtername, $validtypes)) {
 157              // Unknown filter.
 158              throw new InvalidArgumentException(
 159                  "The filter '{$filtername}' was not recognised."
 160              );
 161          }
 162  
 163          $filterclass = $validtypes[$filtername];
 164  
 165          if (!class_exists($filterclass)) {
 166              // Filter class cannot be class autoloaded.
 167              throw new InvalidArgumentException(
 168                  "The filter class '{$filterclass}' for filter '{$filtername}' could not be found."
 169              );
 170          }
 171  
 172          // Pass all supplied arguments to the constructor when adding a new filter.
 173          // This allows for a wider definition of the the filter in child classes.
 174          $this->add_filter(new $filterclass($filtername, ...$args));
 175  
 176          return $this;
 177      }
 178  
 179      /**
 180       * Return the current set of filters.
 181       *
 182       * @return filter[]
 183       */
 184      public function get_filters(): array {
 185          // Sort the filters by their name to ensure consistent output.
 186          // Note: This is not a locale-aware sort, but we don't need this.
 187          // It's primarily for consistency, not for actual sorting.
 188          asort($this->filters);
 189  
 190          return $this->filters;
 191      }
 192  
 193      /**
 194       * Check whether the filter has been added or not.
 195       *
 196       * @param string $filtername
 197       * @return bool
 198       */
 199      public function has_filter(string $filtername): bool {
 200          // We do not check if the filtername is valid, only that it exists.
 201          // This is an existence check and there is no benefit to doing any more.
 202          return array_key_exists($filtername, $this->filters);
 203      }
 204  
 205      /**
 206       * Get the named filter.
 207       *
 208       * @param string $filtername
 209       * @return filter
 210       */
 211      public function get_filter(string $filtername): filter {
 212          if (!array_key_exists($filtername, $this->get_all_filtertypes())) {
 213              throw new UnexpectedValueException("The filter specified ({$filtername}) is invalid.");
 214          }
 215  
 216          if (!array_key_exists($filtername, $this->filters)) {
 217              throw new UnexpectedValueException("The filter specified ({$filtername}) has not been created.");
 218          }
 219  
 220          return $this->filters[$filtername];
 221      }
 222  
 223      /**
 224       * Confirm whether the filter has been correctly specified.
 225       *
 226       * @throws moodle_exception
 227       */
 228      public function check_validity(): void {
 229          // Ensure that all required filters are present.
 230          $missing = [];
 231          foreach (array_keys($this->get_required_filters()) as $filtername) {
 232              if (!array_key_exists($filtername, $this->filters)) {
 233                  $missing[] = $filtername;
 234              }
 235          }
 236  
 237          if (!empty($missing)) {
 238              throw new moodle_exception(
 239                  'missingrequiredfields',
 240                  'core_table',
 241                  '',
 242                  implode(get_string('listsep', 'langconfig') . ' ', $missing)
 243              );
 244          }
 245      }
 246  
 247      /**
 248       * Get the list of required filters in an array of filtername => filter class type.
 249       *
 250       * @return array
 251       */
 252      protected function get_required_filters(): array {
 253          return [];
 254      }
 255  
 256      /**
 257       * Get the list of optional filters in an array of filtername => filter class type.
 258       *
 259       * @return array
 260       */
 261      protected function get_optional_filters(): array {
 262          return [];
 263      }
 264  
 265      /**
 266       * Get all filter valid types in an array of filtername => filter class type.
 267       *
 268       * @return array
 269       */
 270      public function get_all_filtertypes(): array {
 271          if ($this->filtertypes === null) {
 272              $required = $this->get_required_filters();
 273              $optional = $this->get_optional_filters();
 274  
 275              $conflicts = array_keys(array_intersect_key($required, $optional));
 276  
 277              if (!empty($conflicts)) {
 278                  throw new InvalidArgumentException(
 279                      "Some filter types are both required, and optional: " . implode(', ', $conflicts)
 280                  );
 281              }
 282  
 283              $this->filtertypes = array_merge($required, $optional);
 284              asort($this->filtertypes);
 285          }
 286  
 287          return $this->filtertypes;
 288      }
 289  
 290      /**
 291       * Serialize filterset.
 292       *
 293       * @return mixed|object
 294       */
 295      public function jsonSerialize() {
 296          return (object) [
 297              'jointype' => $this->get_join_type(),
 298              'filters' => $this->get_filters(),
 299          ];
 300      }
 301  }