class DataComparison

class DataComparison extends RulesConditionBase {
  
  /**
   * Evaluate the data comparison.
   *
   * @param mixed $data
   *   Supplied data to test.
   * @param string $operation
   *   Data comparison operation. Typically one of:
   *     - "=="
   *     - "<"
   *     - ">"
   *     - "contains" (for strings or arrays)
   *     - "IN" (for arrays or lists).
   * @param mixed $value
   *   The value to be compared against $data.
   *
   * @return bool
   *   The evaluation of the condition.
   */
  protected function doEvaluate($data, $operation, $value) {
    $operation = $operation ? strtolower($operation) : '==';
    switch ($operation) {
      case '<':
        return $data < $value;
      case '>':
        return $data > $value;
      case 'contains':
        return is_string($data) && strpos($data, $value) !== FALSE || is_array($data) && in_array($value, $data);
      case 'in':
        return is_array($value) && in_array($data, $value);
      case '==':
      default:
        // In case both values evaluate to FALSE, further differentiate between
        // NULL values and values evaluating to FALSE.
        if (!$data && !$value) {
          return isset($data) && isset($value) || !isset($data) && !isset($value);
        }
        return $data == $value;
    }
  }
  
  /**
   * {@inheritdoc}
   */
  public function refineContextDefinitions(array $selected_data) {
    if (isset($selected_data['data'])) {
      $this->pluginDefinition['context_definitions']['value']
        ->setDataType($selected_data['data']->getDataType());
      if ($this->getContextValue('operation') == 'IN') {
        $this->pluginDefinition['context_definitions']['value']
          ->setMultiple();
      }
    }
  }

}