[Summary view] [Print] [Text view]

   1  <?php
   2  
   3  declare(strict_types=1);
   4  
   5  namespace Cron;
   6  
   7  use InvalidArgumentException;
   8  
   9  /**
  10   * CRON field factory implementing a flyweight factory.
  11   *
  12   * @see http://en.wikipedia.org/wiki/Cron
  13   */
  14  class FieldFactory implements FieldFactoryInterface
  15  {
  16      /**
  17       * @var array Cache of instantiated fields
  18       */
  19      private $fields = [];
  20  
  21      /**
  22       * Get an instance of a field object for a cron expression position.
  23       *
  24       * @param int $position CRON expression position value to retrieve
  25       *
  26       * @throws InvalidArgumentException if a position is not valid
  27       */
  28      public function getField(int $position): FieldInterface
  29      {
  30          return $this->fields[$position] ?? $this->fields[$position] = $this->instantiateField($position);
  31      }
  32  
  33      private function instantiateField(int $position): FieldInterface
  34      {
  35          switch ($position) {
  36              case CronExpression::MINUTE:
  37                  return new MinutesField();
  38              case CronExpression::HOUR:
  39                  return new HoursField();
  40              case CronExpression::DAY:
  41                  return new DayOfMonthField();
  42              case CronExpression::MONTH:
  43                  return new MonthField();
  44              case CronExpression::WEEKDAY:
  45                  return new DayOfWeekField();
  46          }
  47  
  48          throw new InvalidArgumentException(
  49              ($position + 1) . ' is not a valid position'
  50          );
  51      }
  52  }