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Differences Between: [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   * Applies the same callback to all recorset records.
  19   *
  20   * @since      Moodle 2.9
  21   * @package    core
  22   * @category   dml
  23   * @copyright  2015 David Monllao
  24   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25   */
  26  
  27  namespace core\dml;
  28  
  29  defined('MOODLE_INTERNAL') || die();
  30  
  31  /**
  32   * Iterator that walks through a moodle_recordset applying the provided function.
  33   *
  34   * The internal recordset can be closed using the close() function.
  35   *
  36   * Note that consumers of this class are responsible of closing the recordset,
  37   * although there are some implicit closes under some ciscumstances:
  38   * - Once all recordset records have been iterated
  39   * - The object is destroyed
  40   *
  41   * @since      Moodle 2.9
  42   * @package    core
  43   * @category   dml
  44   * @copyright  2015 David Monllao
  45   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  46   */
  47  class recordset_walk implements \Iterator {
  48  
  49      /**
  50       * @var \moodle_recordset The recordset.
  51       */
  52      protected $recordset;
  53  
  54      /**
  55       * @var callable The callback.
  56       */
  57      protected $callback;
  58  
  59      /**
  60       * @var mixed|null Extra param for the callback.
  61       */
  62      protected $callbackextra;
  63  
  64      /**
  65       * Create a new iterator applying the callback to each record.
  66       *
  67       * @param \moodle_recordset $recordset Recordset to iterate.
  68       * @param callable $callback Apply this function to each record. If using a method, it should be public.
  69       * @param mixed $callbackextra An extra single parameter to pass to the callback. Use a container to pass multiple values.
  70       */
  71      public function __construct(\moodle_recordset $recordset, callable $callback, $callbackextra = null) {
  72          $this->recordset = $recordset;
  73          $this->callback = $callback;
  74          $this->callbackextra = $callbackextra;
  75      }
  76  
  77      /**
  78       * Closes the recordset.
  79       *
  80       * @return void
  81       */
  82      public function __destruct() {
  83          $this->close();
  84      }
  85  
  86      /**
  87       * Returns the current element after applying the callback.
  88       *
  89       * @return mixed|bool The returned value type will depend on the callback.
  90       */
  91      public function current() {
  92  
  93          if (!$this->recordset->valid()) {
  94              return false;
  95          }
  96  
  97          if (!$record = $this->recordset->current()) {
  98              return false;
  99          }
 100  
 101          // Apply callback and return.
 102          if (!is_null($this->callbackextra)) {
 103              return call_user_func($this->callback, $record, $this->callbackextra);
 104          } else {
 105              return call_user_func($this->callback, $record);
 106          }
 107      }
 108  
 109      /**
 110       * Moves the internal pointer to the next record.
 111       *
 112       * @return void
 113       */
 114      public function next() {
 115          return $this->recordset->next();
 116      }
 117  
 118      /**
 119       * Returns current record key.
 120       *
 121       * @return int
 122       */
 123      public function key() {
 124          return $this->recordset->key();
 125      }
 126  
 127      /**
 128       * Returns whether the current position is valid or not.
 129       *
 130       * If we reached the end of the recordset we close as we
 131       * don't allow rewinds. Doing do so we reduce the chance
 132       * of unclosed recordsets.
 133       *
 134       * @return bool
 135       */
 136      public function valid() {
 137          if (!$valid = $this->recordset->valid()) {
 138              $this->close();
 139          }
 140          return $valid;
 141      }
 142  
 143      /**
 144       * Rewind is not supported.
 145       *
 146       * @return void
 147       */
 148      public function rewind() {
 149          // No rewind as it is not implemented in moodle_recordset.
 150          return;
 151      }
 152  
 153      /**
 154       * Closes the recordset.
 155       *
 156       * @return void
 157       */
 158      public function close() {
 159          $this->recordset->close();
 160      }
 161  }