WebformSubmissionConditionsValidator.php in Webform 8.5

Namespace

Drupal\webform

File

src/WebformSubmissionConditionsValidator.php

<?php

namespace Drupal\webform;

use Drupal\Component\Utility\Crypt;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\webform\Plugin\WebformElement\TextBase;
use Drupal\webform\Plugin\WebformElement\WebformCompositeBase;
use Drupal\webform\Plugin\WebformElement\WebformElement;
use Drupal\webform\Plugin\WebformElementManagerInterface;
use Drupal\webform\Utility\WebformArrayHelper;
use Drupal\webform\Utility\WebformElementHelper;

/**
 * Webform submission conditions (#states) validator.
 *
 * @see \Drupal\webform\Element\WebformElementStates
 * @see \Drupal\Core\Form\FormHelper::processStates
 */
class WebformSubmissionConditionsValidator implements WebformSubmissionConditionsValidatorInterface {
  use StringTranslationTrait;

  /**
   * State aliases.
   *
   * @var array
   *
   * @see Drupal.states.State.aliases
   */
  protected $aliases = [
    'enabled' => '!disabled',
    'invisible' => '!visible',
    'invisible-slide' => '!visible-slide',
    'invalid' => '!valid',
    'optional' => '!required',
    'filled' => '!empty',
    'unchecked' => '!checked',
    'expanded' => '!collapsed',
    'open' => '!collapsed',
    'closed' => 'collapsed',
    'readwrite' => '!readonly',
  ];

  /**
   * The webform element manager.
   *
   * @var \Drupal\webform\Plugin\WebformElementManagerInterface
   */
  protected $elementManager;

  /**
   * Constructs a WebformSubmissionConditionsValidator object.
   *
   * @param \Drupal\webform\Plugin\WebformElementManagerInterface $element_manager
   *   The webform element manager.
   */
  public function __construct(WebformElementManagerInterface $element_manager) {
    $this->elementManager = $element_manager;
  }

  /****************************************************************************/

  // Build pages methods.

  /****************************************************************************/

  /**
   * {@inheritdoc}
   */
  public function buildPages(array $pages, WebformSubmissionInterface $webform_submission) {
    foreach ($pages as $page_key => $page) {

      // Check #access which can be set via form alter.
      if ($page['#access'] === FALSE) {
        unset($pages[$page_key]);
      }

      // Check #states (visible/hidden).
      if (!empty($page['#states'])) {
        $state = key($page['#states']);
        $conditions = $page['#states'][$state];
        $result = $this
          ->validateState($state, $conditions, $webform_submission);
        if ($result !== NULL && !$result) {
          unset($pages[$page_key]);
        }
      }
    }
    return $pages;
  }

  /****************************************************************************/

  // Build form methods.

  /****************************************************************************/

  /**
   * {@inheritdoc}
   */
  public function buildForm(array &$form, FormStateInterface $form_state) {

    /** @var \Drupal\webform\WebformSubmissionInterface $webform_submission */
    $webform_submission = $form_state
      ->getFormObject()
      ->getEntity();

    // Get build/visible form elements.
    $visible_elements =& $this
      ->getBuildElements($form);

    // Loop through visible elements with #states.
    foreach ($visible_elements as &$element) {
      $states =& WebformElementHelper::getStates($element);

      // Store original #states in #_webform_states.
      $element['#_webform_states'] = $states;
      foreach ($states as $original_state => $conditions) {
        if (!is_array($conditions)) {
          continue;
        }

        // Process state/negate.
        list($state, $negate) = $this
          ->processState($original_state);

        // If hide/show we need to make sure that validation is not triggered.
        if (strpos($state, 'visible') === 0) {
          $element['#after_build'][] = [
            get_class($this),
            'elementAfterBuild',
          ];
        }
        $targets = $this
          ->getConditionTargetsVisibility($conditions, $visible_elements);

        // Determine if targets are visible or cross page.
        $all_targets_visible = array_sum($targets) === count($targets);
        $has_cross_page_targets = !$all_targets_visible && array_sum($targets);

        // Skip if evaluating conditions when all targets are visible.
        if ($all_targets_visible) {

          // Add .js-webform-states-hidden to element's that are not visible when
          // the form is rendered.
          if (strpos($state, 'visible') === 0 && !$this
            ->validateConditions($conditions, $webform_submission)) {
            $this
              ->addStatesHiddenToElement($element);
          }
          continue;
        }

        // Replace hidden cross page targets with hidden inputs.
        if ($has_cross_page_targets) {
          $cross_page_targets = array_filter($targets, function ($visible) {
            return $visible === FALSE;
          });
          $states[$original_state] = $this
            ->replaceCrossPageTargets($conditions, $webform_submission, $cross_page_targets, $form);
          continue;
        }
        $result = $this
          ->validateConditions($conditions, $webform_submission);

        // Skip invalid conditions.
        if ($result === NULL) {
          continue;
        }

        // Negate the result.
        $result = $negate ? !$result : $result;

        // Apply result to element state.
        switch ($state) {
          case 'required':
            $element['#required'] = $result;
            break;
          case 'readonly':

            // Set custom readonly attribute and class.
            // We can't use the custom #readonly property because it is
            // processed before cross page targets.
            // @see \Drupal\webform\Plugin\WebformElementBase::prepare
            if ($result) {
              $element['#attributes']['readonly'] = 'readonly';
              $element['#wrapper_attributes']['class'][] = 'webform-readonly';
            }
            break;
          case 'disabled':
            $element['#disabled'] = $result;
            break;
          case 'visible':
          case 'visible-slide':
            if (!$result) {

              // Visual hide the element.
              $this
                ->addStatesHiddenToElement($element);

              // Clear the default value.
              if (!isset($element['#states_clear']) || $element['#states_clear'] === TRUE) {
                unset($element['#default_value']);
              }
            }
            break;
          case 'collapsed':
            $element['#open'] = !$result;
            break;
          case 'checked':
            $element['#default_value'] = $result;
            break;
        }

        // Remove #states state/conditions.
        unset($states[$original_state]);
      }

      // Remove #states if all states have been applied.
      if (empty($states)) {
        unset($element['#states']);
      }
    }
  }

  /**
   * Replace hidden cross page targets with hidden inputs.
   *
   * @param array $conditions
   *   An element's conditions.
   * @param \Drupal\webform\WebformSubmissionInterface $webform_submission
   *   A webform submission.
   * @param array $targets
   *   An array of hidden target selectors.
   * @param array $form
   *   A form.
   *
   * @return array
   *   The conditions with cross page targets replaced with hidden inputs.
   */
  public function replaceCrossPageTargets(array $conditions, WebformSubmissionInterface $webform_submission, array $targets, array &$form) {

    // Cache random cross page values.
    static $cross_page_values = [];
    $cross_page_conditions = [];
    foreach ($conditions as $index => $value) {
      if (is_int($index) && is_array($value) && WebformArrayHelper::isSequential($value)) {
        $cross_page_conditions[$index] = $this
          ->replaceCrossPageTargets($value, $webform_submission, $targets, $form);
      }
      else {
        $cross_page_conditions[$index] = $value;
        if (is_string($value) && in_array($value, [
          'and',
          'or',
          'xor',
        ])) {
          continue;
        }
        elseif (is_int($index)) {
          $selector = key($value);
          $condition = $value[$selector];
        }
        else {
          $selector = $index;
          $condition = $value;
        }
        if (!isset($targets[$selector])) {
          continue;
        }
        $condition_result = $this
          ->validateCondition($selector, $condition, $webform_submission);
        if ($condition_result === NULL) {
          continue;
        }
        $target_trigger = $condition_result ? 'value' : '!value';
        $target_name = 'webform_states_' . Crypt::hashBase64($selector);
        $target_selector = ':input[name="' . $target_name . '"]';

        // IMPORTANT:
        // Using a random value to make sure users can't determine a hidden
        // or computed element's value/result.
        if (!isset($cross_page_values[$target_name])) {
          $cross_page_values[$target_name] = rand();
        }
        $target_value = $cross_page_values[$target_name];
        if (is_int($index)) {
          unset($cross_page_conditions[$index][$selector]);
          $cross_page_conditions[$index][$target_selector] = [
            $target_trigger => $target_value,
          ];
        }
        else {
          unset($cross_page_conditions[$selector]);
          $cross_page_conditions[$target_selector] = [
            $target_trigger => $target_value,
          ];
        }

        // Append cross page element's result as a hidden input.
        $form[$target_name] = [
          '#type' => 'hidden',
          '#value' => $target_value,
        ];
      }
    }
    return $cross_page_conditions;
  }

  /****************************************************************************/

  // Validate form methods.

  /****************************************************************************/

  /**
   * {@inheritdoc}
   *
   * @see \Drupal\webform\WebformSubmissionForm::validateForm
   */
  public function validateForm(array &$form, FormStateInterface $form_state) {
    $this
      ->validateFormRecursive($form, $form_state);
  }

  /**
   * Recurse through a form and validate visible elements.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  protected function validateFormRecursive(array $form, FormStateInterface $form_state) {
    foreach ($form as $key => $element) {
      if (!WebformElementHelper::isElement($element, $key) || !WebformElementHelper::isAccessibleElement($element)) {
        continue;
      }
      $this
        ->validateFormElement($element, $form_state);
      $this
        ->validateFormRecursive($element, $form_state);
    }
  }

  /**
   * Validate a form element.
   *
   * @param array $element
   *   A form element.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  protected function validateFormElement(array $element, FormStateInterface $form_state) {
    $states = WebformElementHelper::getStates($element);
    if (empty($states)) {
      return;
    }

    /** @var \Drupal\webform\WebformSubmissionInterface $webform_submission */
    $webform_submission = $form_state
      ->getFormObject()
      ->getEntity();
    foreach ($states as $state => $conditions) {

      // Only required/optional validation is supported.
      if (!in_array($state, [
        'required',
        'optional',
      ])) {
        continue;
      }

      // Element must be an input to be required or optional.
      $element_plugin = $this->elementManager
        ->getElementInstance($element);
      if (!$element_plugin
        ->isInput($element)) {
        continue;
      }

      // Determine if the element is required.
      $is_required = $this
        ->validateConditions($conditions, $webform_submission);
      $is_required = $state === 'optional' ? !$is_required : $is_required;
      if (!$is_required) {
        continue;
      }

      // Determine if the element is empty (but not zero).
      if (isset($element['#webform_key'])) {
        $value = $webform_submission
          ->getElementData($element['#webform_key']);
      }
      else {
        $value = $element['#value'];
      }

      // Perform required validation. Use element's method if available.
      $element_definition = $element_plugin
        ->getFormElementClassDefinition();
      if (method_exists($element_definition, 'setRequiredError')) {
        $element_definition::setRequiredError($element, $form_state);
      }
      else {
        $is_empty = empty($value) && $value !== '0';
        $is_default_input_mask = TextBase::isDefaultInputMask($element, $value);

        // If required and empty then set required error.
        if ($is_empty || $is_default_input_mask) {
          WebformElementHelper::setRequiredError($element, $form_state);
        }
      }
    }
  }

  /****************************************************************************/

  // Submit form methods.

  /****************************************************************************/

  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {

    /** @var \Drupal\webform\WebformSubmissionInterface $webform_submission */
    $webform_submission = $form_state
      ->getFormObject()
      ->getEntity();

    // Check if we are in the middle of multiple wizard form and determine
    // if element access should be checked.
    $current_page = $form_state
      ->get('current_page');
    $check_access = !$current_page || $current_page === WebformInterface::PAGE_CONFIRMATION ? FALSE : TRUE;

    // Get submission data.
    $data = $webform_submission
      ->getData();

    // Recursive through the form and unset unset submission data for
    // form elements that are hidden.
    $this
      ->submitFormRecursive($form, $webform_submission, $data, $check_access);

    // Set submission data.
    $webform_submission
      ->setData($data);
  }

  /**
   * Recursively unset submission data for form elements that are hidden.
   *
   * @param array $elements
   *   An array of form elements.
   * @param \Drupal\webform\WebformSubmissionInterface $webform_submission
   *   A webform submission.
   * @param array $data
   *   A webform submission's data.
   * @param bool $check_access
   *   Flag that determine if the currrent form element's access
   *   should be checked.
   * @param bool $visible
   *   Flag that determine if the currrent form elements are visible.
   */
  protected function submitFormRecursive(array $elements, WebformSubmissionInterface $webform_submission, array &$data, $check_access, $visible = TRUE) {
    foreach ($elements as $key => &$element) {
      if (!WebformElementHelper::isElement($element, $key)) {
        continue;
      }

      // Skip if element's #states_clear is FALSE.
      if (isset($element['#states_clear']) && $element['#states_clear'] === FALSE) {
        continue;
      }

      // Skip if element #_webform_access should be checked to
      // preserve default values.
      if ($check_access && isset($element['#_webform_access']) && $element['#_webform_access'] === FALSE) {
        continue;
      }

      // Determine if the element is visible.
      $element_visible = $visible && $this
        ->isElementVisible($element, $webform_submission) ? TRUE : FALSE;

      // Set data to empty array or string for any webform element that is hidden.
      if (!$element_visible && !empty($element['#webform_key']) && isset($data[$key])) {
        $data[$key] = is_array($data[$key]) ? [] : '';
      }
      $this
        ->submitFormRecursive($element, $webform_submission, $data, $check_access, $element_visible);
    }
  }

  /****************************************************************************/

  // Element hide/show validation methods.

  /****************************************************************************/

  /**
   * Webform element #after_build callback: Wrap #element_validate so that we suppress element validation errors.
   */
  public static function elementAfterBuild(array $element, FormStateInterface $form_state) {
    return WebformElementHelper::setElementValidate($element, [
      get_called_class(),
      'elementValidate',
    ]);
  }

  /**
   * Webform conditional #element_validate callback: Execute #element_validate and suppress errors.
   */
  public static function elementValidate(array &$element, FormStateInterface $form_state) {

    // Element validation is trigger sequentially.
    // Triggers must be validated before dependants.
    //
    // Build webform submission with validated and processed data.
    // Webform submission must be rebuilt every time since the
    // $element and $form_state values can be changed by validation callbacks.

    /** @var \Drupal\webform\WebformSubmissionForm $form_object */
    $form_object = $form_state
      ->getFormObject();
    $complete_form =& $form_state
      ->getCompleteForm();
    $webform_submission = $form_object
      ->buildEntity($complete_form, $form_state);

    /** @var \Drupal\webform\WebformSubmissionConditionsValidatorInterface $conditions_validator */
    $conditions_validator = \Drupal::service('webform_submission.conditions_validator');
    if ($conditions_validator
      ->isElementVisible($element, $webform_submission)) {
      WebformElementHelper::triggerElementValidate($element, $form_state);
    }
    else {
      WebformElementHelper::suppressElementValidate($element, $form_state);
    }
  }

  /****************************************************************************/

  // Element state methods.

  /****************************************************************************/

  /**
   * {@inheritdoc}
   */
  public function isElementVisible(array $element, WebformSubmissionInterface $webform_submission) {
    $states = WebformElementHelper::getStates($element);
    $visible = TRUE;
    foreach ($states as $state => $conditions) {
      if (!is_array($conditions)) {
        continue;
      }

      // Process state/negate.
      list($state, $negate) = $this
        ->processState($state);
      $result = $this
        ->validateConditions($conditions, $webform_submission);

      // Skip invalid conditions.
      if ($result === NULL) {
        continue;
      }

      // Negate the result.
      $result = $negate ? !$result : $result;

      // Apply result to element state.
      if (strpos($state, 'visible') === 0 && $result === FALSE) {
        $visible = FALSE;
      }
    }
    return $visible;
  }

  /**
   * {@inheritdoc}
   */
  public function isElementEnabled(array $element, WebformSubmissionInterface $webform_submission) {
    $states = WebformElementHelper::getStates($element);
    $enabled = TRUE;
    foreach ($states as $state => $conditions) {
      if (!is_array($conditions)) {
        continue;
      }

      // Process state/negate.
      list($state, $negate) = $this
        ->processState($state);
      $result = $this
        ->validateConditions($conditions, $webform_submission);

      // Skip invalid conditions.
      if ($result === NULL) {
        continue;
      }

      // Negate the result.
      $result = $negate ? !$result : $result;

      // Apply result to element state.
      if ($state === 'disabled' && $result === TRUE) {
        $enabled = FALSE;
      }
    }
    return $enabled;
  }

  /****************************************************************************/

  // Validate state methods.

  /****************************************************************************/

  /**
   * {@inheritdoc}
   */
  public function validateState($state, array $conditions, WebformSubmissionInterface $webform_submission) {

    // Process state/negate.
    list($state, $negate) = $this
      ->processState($state);

    // Validation conditions.
    $result = $this
      ->validateConditions($conditions, $webform_submission);

    // Skip invalid conditions.
    if ($result === NULL) {
      return NULL;
    }

    // Negate the result.
    return $negate ? !$result : $result;
  }

  /****************************************************************************/

  // Validate condition methods.

  /****************************************************************************/

  /**
   * {@inheritdoc}
   */
  public function validateConditions(array $conditions, WebformSubmissionInterface $webform_submission) {
    if (empty($conditions)) {
      return TRUE;
    }

    // Determine condition logic.
    // @see Drupal.states.Dependent.verifyConstraints
    if (WebformArrayHelper::isSequential($conditions)) {
      $condition_logic = in_array('xor', $conditions) ? 'xor' : 'or';
    }
    else {
      $condition_logic = 'and';
    }
    $condition_results = [];
    foreach ($conditions as $index => $value) {

      // Skip and, or, and xor.
      if (is_string($value) && in_array($value, [
        'and',
        'or',
        'xor',
      ])) {
        continue;
      }
      if (is_int($index) && is_array($value)) {

        // Validate nested conditions.
        // NOTE: Nested conditions is not supported via the UI.
        $nested_result = $this
          ->validateConditions($value, $webform_submission);
        if ($nested_result === NULL) {
          return NULL;
        }
        $condition_results[] = $nested_result;
      }
      else {
        if (is_int($index)) {
          $selector = key($value);
          $condition = $value[$selector];
        }
        else {
          $selector = $index;
          $condition = $value;
        }
        $condition_result = $this
          ->validateCondition($selector, $condition, $webform_submission);
        if ($condition_result === NULL) {
          return NULL;
        }
        $condition_results[] = $this
          ->validateCondition($selector, $condition, $webform_submission);
      }
    }

    // Process condition logic. (XOR, AND, or OR)
    $conditions_sum = array_sum($condition_results);
    $conditions_total = count($condition_results);
    switch ($condition_logic) {
      case 'xor':
        return $conditions_sum === 1;
      case 'or':
        return (bool) $conditions_sum;
      case 'and':
        return $conditions_sum === $conditions_total;
      default:

        // Never called.
        return NULL;
    }
  }

  /**
   * Validate #state condition.
   *
   * @param string $selector
   *   The #state condition selector.
   * @param array $condition
   *   A condition.
   * @param \Drupal\webform\WebformSubmissionInterface $webform_submission
   *   A webform submission.
   *
   * @return bool|null
   *   TRUE if the condition validates. NULL if condition can't be processed.
   *   NULL is returned when there is invalid selector and missing element
   *   in the conditions.
   */
  protected function validateCondition($selector, array $condition, WebformSubmissionInterface $webform_submission) {

    // Ignore invalid selector and return NULL.
    $input_name = static::getSelectorInputName($selector);
    if (!$input_name) {
      return NULL;
    }
    $element_key = static::getInputNameAsArray($input_name, 0);
    $element = $webform_submission
      ->getWebform()
      ->getElement($element_key);

    // If no element is found try checking file uploads which use
    // :input[name="files[ELEMENT_KEY].
    // @see \Drupal\webform\Plugin\WebformElement\WebformManagedFileBase::getElementSelectorOptions
    if (!$element && strpos($selector, ':input[name="files[') !== FALSE) {
      $element_key = static::getInputNameAsArray($input_name, 1);
      $element = $webform_submission
        ->getWebform()
        ->getElement($element_key);
    }

    // Ignore missing dependee element and return NULL.
    if (!$element) {
      return NULL;
    }

    // Issue #1149078: States API doesn't work with multiple select fields.
    // @see https://www.drupal.org/project/drupal/issues/1149078
    if (WebformArrayHelper::isSequential($condition)) {
      $sub_condition_results = [];
      foreach ($condition as $sub_condition) {
        $sub_condition_results[] = $this
          ->checkCondition($element, $selector, $sub_condition, $webform_submission);
      }

      // Evaluate sub-conditions using the 'OR' operator.
      return (bool) array_sum($sub_condition_results);
    }
    else {
      return $this
        ->checkCondition($element, $selector, $condition, $webform_submission);
    }
  }

  /**
   * Check a condition.
   *
   * @param array $element
   *   An element.
   * @param string $selector
   *   The element's selector.
   * @param array $condition
   *   The condition.
   * @param \Drupal\webform\WebformSubmissionInterface $webform_submission
   *   A webform submission.
   *
   * @return bool|null
   *   TRUE if condition is validated. NULL if the condition can't be evaluated.
   */
  protected function checkCondition(array $element, $selector, array $condition, WebformSubmissionInterface $webform_submission) {
    $trigger = key($condition);
    $trigger_value = $condition[$trigger];
    $element_plugin = $this->elementManager
      ->getElementInstance($element);

    // Ignored conditions for generic webform elements.
    if ($element_plugin instanceof WebformElement) {
      return TRUE;
    }
    $element_value = $element_plugin
      ->getElementSelectorInputValue($selector, $trigger, $element, $webform_submission);

    // Process trigger sub state used for custom #states API validation.
    // @see Drupal.behaviors.webformStatesComparisons
    // @see http://drupalsun.com/julia-evans/2012/03/09/extending-form-api-states-regular-expressions
    if ($trigger === 'value' && is_array($trigger_value)) {
      $trigger_substate = key($trigger_value);
      if (in_array($trigger_substate, [
        'pattern',
        '!pattern',
        'less',
        'less_equal',
        'greater',
        'greater_equal',
        'between',
        '!between',
      ])) {
        $trigger = $trigger_substate;
        $trigger_value = reset($trigger_value);
      }
    }

    // Process trigger state/negate.
    list($trigger, $trigger_negate) = $this
      ->processState($trigger);

    // Process triggers (aka remote conditions).
    // @see \Drupal\webform\Element\WebformElementStates::processWebformStates
    if ($element_plugin
      ->hasMultipleValues($element) && $trigger !== 'empty') {
      $result = FALSE;
      $element_values = (array) $element_value;
      foreach ($element_values as $element_value) {
        $trigger_result = $this
          ->checkConditionTrigger($trigger, $trigger_value, $element_value);
        if ($trigger_result !== FALSE) {
          $result = $trigger_result;
        }
      }
    }
    else {
      $result = $this
        ->checkConditionTrigger($trigger, $trigger_value, $element_value);
    }
    if ($result === NULL) {
      return FALSE;
    }
    return $trigger_negate ? !$result : $result;
  }

  /**
   * Process condition trigger.
   *
   * @param string $trigger
   *   The trigger.
   * @param string $trigger_value
   *   The trigger value.
   * @param string|array $element_value
   *   The element value.
   *
   * @return bool|null
   *   The result.
   */
  protected function checkConditionTrigger($trigger, $trigger_value, $element_value) {

    // Process triggers (aka remote conditions).
    // @see \Drupal\webform\Element\WebformElementStates::processWebformStates
    switch ($trigger) {
      case 'empty':
        $empty = empty($element_value) && $element_value !== '0';
        return $empty === (bool) $trigger_value;
      case 'checked':
        return (bool) $element_value === (bool) $trigger_value;
      case 'value':
        return (string) $element_value === (string) $trigger_value;
      case 'pattern':

        // PHP: Convert JavaScript-escaped Unicode characters to PCRE
        // escape sequence format.
        // @see \Drupal\webform\Plugin\WebformElement\TextBase::validatePattern
        $pcre_pattern = preg_replace('/\\\\u([a-fA-F0-9]{4})/', '\\x{\\1}', $trigger_value);
        return preg_match('{' . $pcre_pattern . '}u', $element_value);
      case 'less':
        return $element_value !== '' && floatval($trigger_value) > floatval($element_value);
      case 'less_equal':
        return $element_value !== '' && floatval($trigger_value) >= floatval($element_value);
      case 'greater':
        return $element_value !== '' && floatval($trigger_value) < floatval($element_value);
      case 'greater_equal':
        return $element_value !== '' && floatval($trigger_value) <= floatval($element_value);
      case 'between':
        if ($element_value === '') {
          return NULL;
        }
        $greater = NULL;
        $less = NULL;
        if (strpos($trigger_value, ':') === FALSE) {
          $greater = $trigger_value;
        }
        else {
          list($greater, $less) = explode(':', $trigger_value);
        }
        $is_greater_than = $greater === NULL || $greater === '' || floatval($element_value) >= floatval($greater);
        $is_less_than = $less === NULL || $less === '' || floatval($element_value) <= floatval($less);
        return $is_greater_than && $is_less_than;
      default:
        return NULL;
    }
  }

  /****************************************************************************/

  // State methods.

  /****************************************************************************/

  /**
   * Process state by mapping aliases and negation.
   *
   * @param string $state
   *   A state.
   *
   * @return array
   *   An array containing state and negate
   */
  protected function processState($state) {

    // Set aliases.
    if (isset($this->aliases[$state])) {
      $state = $this->aliases[$state];
    }

    // Set negate.
    $negate = FALSE;
    if (strpos($state, '!') === 0) {
      $negate = TRUE;
      $state = ltrim($state, '!');
    }
    return [
      $state,
      $negate,
    ];
  }

  /****************************************************************************/

  // Element methods.

  /****************************************************************************/

  /**
   * Build and get visible elements from a form.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   *
   * @return array
   *   Visible elements.
   */
  protected function &getBuildElements(array &$form) {
    $elements = [];
    $this
      ->getBuildElementsRecursive($elements, $form);
    return $elements;
  }

  /**
   * Recurse through a form, review #states/#required, and get visible elements.
   *
   * @param array $elements
   *   Visible elements with #states property.
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param array $parent_states
   *   An associative array containing 'required'/'optional' states from parent
   *   container to be set on the element.
   */
  protected function getBuildElementsRecursive(array &$elements, array &$form, array $parent_states = []) {
    foreach ($form as $key => &$element) {
      if (!WebformElementHelper::isElement($element, $key)) {
        continue;
      }

      // Pass parent states to sub-element states.
      $subelement_states = $parent_states;
      if (!empty($element['#states']) || !empty($parent_states)) {
        if (!empty($element['#required'])) {

          // If element has #states and is #required there may be a conflict where
          // visibly hidden elements are required. The solution is to convert
          // #required into corresponding 'required/optional' states based on
          // 'visible/invisible' states.
          if (!isset($element['#states']['required']) && !isset($element['#states']['optional'])) {
            if (isset($element['#states']['visible'])) {
              $element['#states']['required'] = $element['#states']['visible'];
            }
            elseif (isset($element['#states']['visible-slide'])) {
              $element['#states']['required'] = $element['#states']['visible-slide'];
            }
            elseif (isset($element['#states']['invisible'])) {
              $element['#states']['optional'] = $element['#states']['invisible'];
            }
            elseif (isset($element['#states']['invisible-slide'])) {
              $element['#states']['optional'] = $element['#states']['invisible-slide'];
            }
            elseif ($parent_states) {
              $element += [
                '#states' => [],
              ];
              $element['#states'] += $parent_states;
            }
          }
          if (isset($element['#states']['optional']) || isset($element['#states']['required'])) {
            unset($element['#required']);
          }

          // Store a reference to the original #required value so that
          // form alter hooks know if the element's required/optional #states
          // are based the 'visible/invisible' states or the parent states.
          if (!isset($element['#required'])) {
            $element['#_required'] = TRUE;
          }
        }

        // If this container element has a visibility state, make its
        // sub-elements required/optional based on this state.
        if (isset($element['#states']['visible'])) {
          $subelement_states = [
            'required' => $element['#states']['visible'],
          ];
        }
        elseif (isset($element['#states']['visible-slide'])) {
          $subelement_states = [
            'required' => $element['#states']['visible-slide'],
          ];
        }
        elseif (isset($element['#states']['invisible'])) {
          $subelement_states = [
            'optional' => $element['#states']['invisible'],
          ];
        }
        elseif (isset($element['#states']['invisible-slide'])) {
          $subelement_states = [
            'optional' => $element['#states']['invisible-slide'],
          ];
        }
      }

      // Store original #access in #_webform_access for all elements.
      // @see \Drupal\webform\WebformSubmissionConditionsValidator::submitFormRecursive
      if (isset($element['#access'])) {
        $element['#_webform_access'] = $element['#access'];
      }

      // Skip if element is not accessible.
      if (!WebformElementHelper::isAccessibleElement($element)) {
        continue;
      }
      $elements[$key] =& $element;
      $this
        ->getBuildElementsRecursive($elements, $element, $subelement_states);
      $element_plugin = $this->elementManager
        ->getElementInstance($element);
      if ($element_plugin instanceof WebformCompositeBase && !$element_plugin
        ->hasMultipleValues($element)) {

        // Handle composite with single item.
        if ($subelement_states) {
          $composite_elements = $element_plugin
            ->getCompositeElements();
          foreach ($composite_elements as $composite_key => $composite_element) {

            // Skip if #access is set to FALSE.
            if (isset($element['#' . $composite_key . '__access']) && $element['#' . $composite_key . '__access'] === FALSE) {
              continue;
            }

            // Move #composite__required to #composite___required which triggers
            // conditional #_required handling.
            if (!empty($element['#' . $composite_key . '__required'])) {
              unset($element['#' . $composite_key . '__required']);
              $element['#' . $composite_key . '___required'] = TRUE;
              $element['#' . $composite_key . '__states'] = $subelement_states;
            }
          }
        }
      }
      elseif (isset($element['#element']) && isset($element['#webform_composite_elements'])) {

        // Handle composite with multiple items and custom composite elements.
        //
        // For $element['#elements'] ...
        // @see \Drupal\webform\Plugin\WebformElement\WebformCompositeBase::prepareMultipleWrapper
        //
        // For $element['#webform_composite_elements'] ...
        // @see \Drupal\webform\Plugin\WebformElement\WebformCompositeBase::initializeCompositeElements
        // @see \Drupal\webform_composite\Plugin\WebformElement\WebformComposite::initializeCompositeElements
        //
        // Recurse through a composite's sub elements.
        $this
          ->getBuildElementsRecursive($elements, $element['#element'], $subelement_states);
      }
    }
  }

  /**
   * Get the visibility state for all of conditions targets.
   *
   * @param array $conditions
   *   An associative array containing conditions.
   * @param array $elements
   *   An associative array of visible elements.
   *
   * @return array
   *   An associative array keyed by target selectors with a boolean state.
   */
  protected function getConditionTargetsVisibility(array $conditions, array $elements) {
    $targets = [];
    $this
      ->getConditionTargetsVisibilityRecursive($conditions, $targets);
    foreach ($targets as $selector) {

      // Ignore invalid selector and return FALSE.
      $input_name = static::getSelectorInputName($selector);
      if (!$input_name) {
        $targets[$selector] = FALSE;
        continue;
      }

      // Check if the input's element is visible.
      $element_key = static::getInputNameAsArray($input_name, 0);
      if (!isset($elements[$element_key])) {
        $targets[$selector] = FALSE;
        continue;
      }
      $targets[$selector] = TRUE;
    }
    return $targets;
  }

  /**
   * Recursively collect a conditions targets.
   *
   * @param array $conditions
   *   An associative array containing conditions.
   * @param array $targets
   *   An associative array keyed by target selectors with a boolean state.
   */
  protected function getConditionTargetsVisibilityRecursive(array $conditions, array &$targets = []) {
    foreach ($conditions as $index => $value) {
      if (is_int($index) && is_array($value) && WebformArrayHelper::isSequential($value)) {

        // Recurse downward and get nested target element.
        // NOTE: Nested conditions is not supported via the UI.
        $this
          ->getConditionTargetsVisibilityRecursive($value, $targets);
      }
      elseif (is_string($value) && in_array($value, [
        'and',
        'or',
        'xor',
      ])) {

        // Skip AND, OR, or XOR operators.
        continue;
      }
      elseif (is_int($index)) {
        $selector = key($value);
        $targets[$selector] = $selector;
      }
      else {
        $selector = $index;
        $targets[$selector] = $selector;
      }
    }
  }

  /**
   * Add .js-webform-states-hidden to an element.
   *
   * @param array $element
   *   An element.
   */
  protected function addStatesHiddenToElement(array &$element) {
    $element_plugin = $this->elementManager
      ->getElementInstance($element);
    $attributes_property = $element_plugin
      ->hasWrapper($element) || $element_plugin
      ->getPluginDefinition()['states_wrapper'] ? '#wrapper_attributes' : '#attributes';
    $element += [
      $attributes_property => [],
    ];
    $element[$attributes_property] += [
      'class' => [],
    ];
    $element[$attributes_property]['class'][] = 'js-webform-states-hidden';
  }

  /****************************************************************************/

  // Static input and selector methods.
  // @see \Drupal\webform\Plugin\WebformElementBase::getElementSelectorInputValue

  /****************************************************************************/

  /**
   * Get input name from CSS :input[name="*"] selector.
   *
   * @param string $selector
   *   A CSS :input[name="*"] selector.
   *
   * @return string|null
   *   The input name or NULL if selector can not be parsed
   */
  public static function getSelectorInputName($selector) {
    return preg_match('/\\:input\\[name="([^"]+)"\\]/', $selector, $match) ? $match[1] : NULL;
  }

  /**
   * Parse input name which can container nested elements defined using #tree.
   *
   * Converts 'input[subkey]' into ['input', 'subkey'].
   *
   * @param string $name
   *   The input name.
   * @param int $index
   *   A specific input name index to be returned.
   *
   * @return array|string
   *   An array containing the input name and keys or specific input name.
   *
   * @see http://php.net/manual/en/faq.html.php#faq.html.arrays
   */
  public static function getInputNameAsArray($name, $index = NULL) {
    $name = str_replace([
      '][',
      '[',
      ']',
    ], [
      '|',
      '|',
      '',
    ], $name);
    $array = explode('|', $name);
    if ($index !== NULL) {
      return isset($array[$index]) ? $array[$index] : NULL;
    }
    else {
      return $array;
    }
  }

}

Classes

Name	Description
WebformSubmissionConditionsValidator	Webform submission conditions (#states) validator.