diff --git a/src/Utility/ArrayObject.php b/src/Utility/ArrayObject.php
new file mode 100644
index 0000000000000000000000000000000000000000..b5d448ca107cdc3168f87c0da118f633013b23f8
--- /dev/null
+++ b/src/Utility/ArrayObject.php
@@ -0,0 +1,413 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\ui_suite_bootstrap\Utility;
+
+use Drupal\Component\Utility\NestedArray;
+use Drupal\Core\Cache\RefinableCacheableDependencyInterface;
+use Drupal\Core\Render\AttachmentsInterface;
+use Drupal\Core\Render\BubbleableMetadata;
+
+/**
+ * Custom ArrayObject implementation.
+ *
+ * The native ArrayObject is unnecessarily complicated.
+ *
+ * @ingroup utility
+ */
+class ArrayObject implements \IteratorAggregate, \ArrayAccess, \Serializable, \Countable, AttachmentsInterface, RefinableCacheableDependencyInterface {
+
+ /**
+ * The array.
+ *
+ * @var array
+ */
+ protected $array;
+
+ /**
+ * Array object constructor.
+ *
+ * @param array $array
+ * An array.
+ */
+ public function __construct(array $array = []) {
+ $this->array = $array;
+ }
+
+ /**
+ * Returns whether the requested key exists.
+ *
+ * @param mixed $key
+ * A key.
+ *
+ * @return bool
+ * TRUE or FALSE
+ */
+ public function __isset($key) {
+ return $this->offsetExists($key);
+ }
+
+ /**
+ * Sets the value at the specified key to value.
+ *
+ * @param mixed $key
+ * A key.
+ * @param mixed $value
+ * A value.
+ */
+ public function __set($key, $value) {
+ $this->offsetSet($key, $value);
+ }
+
+ /**
+ * Unsets the value at the specified key.
+ *
+ * @param mixed $key
+ * A key.
+ */
+ public function __unset($key) {
+ $this->offsetUnset($key);
+ }
+
+ /**
+ * Returns the value at the specified key by reference.
+ *
+ * @param mixed $key
+ * A key.
+ *
+ * @return mixed
+ * The stored value.
+ */
+ public function &__get($key) {
+ $ret = &$this->offsetGet($key);
+ return $ret;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function addAttachments(array $attachments) {
+ BubbleableMetadata::createFromRenderArray($this->array)->addAttachments($attachments)->applyTo($this->array);
+ return $this;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function addCacheContexts(array $cache_contexts) {
+ BubbleableMetadata::createFromRenderArray($this->array)->addCacheContexts($cache_contexts)->applyTo($this->array);
+ return $this;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function addCacheTags(array $cache_tags) {
+ BubbleableMetadata::createFromRenderArray($this->array)->addCacheTags($cache_tags)->applyTo($this->array);
+ return $this;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function addCacheableDependency($other_object) {
+ BubbleableMetadata::createFromRenderArray($this->array)->addCacheableDependency($other_object)->applyTo($this->array);
+ return $this;
+ }
+
+ /**
+ * Appends the value.
+ *
+ * @param mixed $value
+ * A value.
+ */
+ public function append($value): void {
+ $this->array[] = $value;
+ }
+
+ /**
+ * Sort the entries by value.
+ */
+ public function asort(): void {
+ \asort($this->array);
+ }
+
+ /**
+ * Merges an object's cacheable metadata into the variables array.
+ *
+ * @param \Drupal\Core\Cache\CacheableDependencyInterface|mixed $object
+ * The object whose cacheability metadata to retrieve. If it implements
+ * CacheableDependencyInterface, its cacheability metadata will be used,
+ * otherwise, the passed in object must be assumed to be uncacheable, so
+ * max-age 0 is set.
+ *
+ * @return $this
+ */
+ public function bubbleObject($object) {
+ BubbleableMetadata::createFromRenderArray($this->array)->merge(BubbleableMetadata::createFromObject($object))->applyTo($this->array);
+ return $this;
+ }
+
+ /**
+ * Merges a render array's cacheable metadata into the variables array.
+ *
+ * @param array $build
+ * A render array.
+ *
+ * @return $this
+ */
+ public function bubbleRenderArray(array $build) {
+ BubbleableMetadata::createFromRenderArray($this->array)->merge(BubbleableMetadata::createFromRenderArray($build))->applyTo($this->array);
+ return $this;
+ }
+
+ /**
+ * Get the number of public properties in the ArrayObject.
+ *
+ * @return int
+ * The count.
+ */
+ public function count(): int {
+ return \count($this->array);
+ }
+
+ /**
+ * Exchange the array for another one.
+ *
+ * @param array|ArrayObject $data
+ * New data.
+ *
+ * @throws \InvalidArgumentException
+ * When the passed data is not an array or an instance of ArrayObject.
+ *
+ * @return array
+ * The old array.
+ */
+ public function exchangeArray($data) {
+ if (!\is_array($data) && \is_object($data) && !($data instanceof ArrayObject)) {
+ throw new \InvalidArgumentException('Passed variable is not an array or an instance of \Drupal\bootstrap\Utility\ArrayObject.');
+ }
+ if (\is_object($data) && $data instanceof ArrayObject) {
+ $data = $data->getArrayCopy();
+ }
+ $old = $this->array;
+ $this->array = $data;
+ return $old;
+ }
+
+ /**
+ * Creates a copy of the ArrayObject.
+ *
+ * @return array
+ * A copy of the array.
+ */
+ public function getArrayCopy() {
+ return $this->array;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getAttachments() {
+ return BubbleableMetadata::createFromRenderArray($this->array)->getAttachments();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getCacheContexts() {
+ return BubbleableMetadata::createFromRenderArray($this->array)->getCacheContexts();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getCacheTags() {
+ return BubbleableMetadata::createFromRenderArray($this->array)->getCacheTags();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getCacheMaxAge() {
+ return BubbleableMetadata::createFromRenderArray($this->array)->getCacheMaxAge();
+ }
+
+ /**
+ * Creates a new iterator from an ArrayObject instance.
+ *
+ * @return \ArrayIterator
+ * An array iterator.
+ */
+ public function getIterator(): \Traversable {
+ return new \ArrayIterator($this->array);
+ }
+
+ /**
+ * Sort the entries by key.
+ */
+ public function ksort(): void {
+ \ksort($this->array);
+ }
+
+ /**
+ * Merges multiple values into the array.
+ *
+ * @param array $values
+ * An associative key/value array.
+ * @param bool $recursive
+ * Flag determining whether or not to recursively merge key/value pairs.
+ *
+ * @SuppressWarnings(PHPMD.BooleanArgumentFlag)
+ */
+ public function merge(array $values, $recursive = TRUE): void {
+ if ($recursive) {
+ $this->array = NestedArray::mergeDeepArray([$this->array, $values], TRUE);
+ }
+ else {
+ $this->array += $values;
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function mergeCacheMaxAge($max_age) {
+ BubbleableMetadata::createFromRenderArray($this->array)->mergeCacheMaxAge($max_age)->applyTo($this->array);
+ return $this;
+ }
+
+ /**
+ * Sort an array using a case insensitive "natural order" algorithm.
+ */
+ public function natcasesort(): void {
+ \natcasesort($this->array);
+ }
+
+ /**
+ * Sort entries using a "natural order" algorithm.
+ */
+ public function natsort(): void {
+ \natsort($this->array);
+ }
+
+ /**
+ * Returns whether the requested key exists.
+ *
+ * @param mixed $key
+ * A key.
+ *
+ * @return bool
+ * TRUE or FALSE
+ */
+ public function offsetExists($key): bool {
+ return isset($this->array[$key]);
+ }
+
+ /**
+ * Returns the value at the specified key.
+ *
+ * @param mixed $key
+ * A key.
+ * @param mixed $default
+ * The default value to set if $key does not exist.
+ *
+ * @return mixed
+ * The value.
+ */
+ public function &offsetGet($key, $default = NULL): mixed {
+ if (!$this->offsetExists($key)) {
+ $this->array[$key] = $default;
+ }
+ $ret = &$this->array[$key];
+ return $ret;
+ }
+
+ /**
+ * Sets the value at the specified key to value.
+ *
+ * @param mixed $key
+ * A key.
+ * @param mixed $value
+ * A value.
+ */
+ public function offsetSet($key, $value): void {
+ $this->array[$key] = $value;
+ }
+
+ /**
+ * Unsets the value at the specified key.
+ *
+ * @param mixed $key
+ * A key.
+ */
+ public function offsetUnset($key): void {
+ if ($this->offsetExists($key)) {
+ unset($this->array[$key]);
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function setAttachments(array $attachments) {
+ BubbleableMetadata::createFromRenderArray($this->array)->setAttachments($attachments)->applyTo($this->array);
+ return $this;
+ }
+
+ /**
+ * Sort entries with a user-defined function and maintain key association.
+ *
+ * @param mixed $function
+ * A callable function.
+ */
+ public function uasort($function): void {
+ if (\is_callable($function)) {
+ \uasort($this->array, $function);
+ }
+ }
+
+ /**
+ * Sort the entries by keys using a user-defined comparison function.
+ *
+ * @param mixed $function
+ * A callable function.
+ */
+ public function uksort($function): void {
+ if (\is_callable($function)) {
+ \uksort($this->array, $function);
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function serialize() {
+ return \serialize($this->__serialize());
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function unserialize($serialized) {
+ // phpcs:disable
+ $this->__unserialize(\unserialize($serialized));
+ // phpcs:enable
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function __serialize(): array {
+ return \get_object_vars($this);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function __unserialize(array $data): void {
+ $this->exchangeArray($data['array']);
+ }
+
+}
diff --git a/src/Utility/Attributes.php b/src/Utility/Attributes.php
new file mode 100644
index 0000000000000000000000000000000000000000..7127c2e632679ed644999cff52dd8684716a067d
--- /dev/null
+++ b/src/Utility/Attributes.php
@@ -0,0 +1,192 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\ui_suite_bootstrap\Utility;
+
+use Drupal\Core\Template\AttributeValueBase;
+
+/**
+ * Class to help modify attributes.
+ *
+ * @ingroup utility
+ */
+class Attributes extends ArrayObject {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function __construct(array &$array = []) {
+ $this->array = &$array;
+ }
+
+ /**
+ * Add class(es) to the array.
+ *
+ * @param string|array $class
+ * An individual class or an array of classes to add.
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::getClasses()
+ */
+ public function addClass($class): void {
+ // Handle core Attribute based object values.
+ // @see https://www.drupal.org/project/bootstrap/issues/3020266
+ if ($class instanceof AttributeValueBase) {
+ $class = $class->value();
+ }
+ $classes = &$this->getClasses();
+ $classes = \array_unique(\array_merge($classes, (array) $class));
+ }
+
+ /**
+ * Retrieve a specific attribute from the array.
+ *
+ * @param string $name
+ * The specific attribute to retrieve.
+ * @param mixed $default
+ * (optional) The default value to set if the attribute does not exist.
+ *
+ * @return mixed
+ * A specific attribute value, passed by reference.
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\ArrayObject::offsetGet()
+ */
+ public function &getAttribute($name, $default = NULL) {
+ return $this->offsetGet($name, $default);
+ }
+
+ /**
+ * Retrieves classes from the array.
+ *
+ * @return array
+ * The classes array, passed by reference.
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\ArrayObject::offsetGet()
+ */
+ public function &getClasses(): array {
+ $classes = &$this->offsetGet('class', []);
+ $classes = \array_unique($classes);
+ return $classes;
+ }
+
+ /**
+ * Indicates whether a specific attribute is set.
+ *
+ * @param string $name
+ * The attribute to search for.
+ *
+ * @return bool
+ * TRUE or FALSE.
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\ArrayObject::offsetExists()
+ */
+ public function hasAttribute($name): bool {
+ return $this->offsetExists($name);
+ }
+
+ /**
+ * Indicates whether a class is present in the array.
+ *
+ * @param string|array $class
+ * The class or array of classes to search for.
+ * @param bool $all
+ * Flag determining to check if all classes are present.
+ *
+ * @return bool
+ * TRUE or FALSE.
+ *
+ * @SuppressWarnings(PHPMD.BooleanArgumentFlag)
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::getClasses()
+ */
+ public function hasClass($class, $all = FALSE): bool {
+ $classes = (array) $class;
+ $result = \array_intersect($classes, $this->getClasses());
+ return $all ? $result && \count($classes) === \count($result) : (bool) $result;
+ }
+
+ /**
+ * Removes an attribute from the array.
+ *
+ * @param string|array $name
+ * The name of the attribute to remove.
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\ArrayObject::offsetUnset()
+ */
+ public function removeAttribute($name): void {
+ $this->offsetUnset($name);
+ }
+
+ /**
+ * Removes a class from the attributes array.
+ *
+ * @param string|array $class
+ * An individual class or an array of classes to remove.
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::getClasses()
+ */
+ public function removeClass($class): void {
+ $classes = &$this->getClasses();
+ $classes = \array_values(\array_diff($classes, (array) $class));
+ }
+
+ /**
+ * Replaces a class in the attributes array.
+ *
+ * @param string $old
+ * The old class to remove.
+ * @param string $new
+ * The new class. It will not be added if the $old class does not exist.
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::getClasses()
+ */
+ public function replaceClass($old, $new): void {
+ $classes = &$this->getClasses();
+ $key = \array_search($old, $classes, TRUE);
+ if ($key !== FALSE) {
+ $classes[$key] = $new;
+ }
+ }
+
+ /**
+ * Sets an attribute on the array.
+ *
+ * @param string $name
+ * The name of the attribute to set.
+ * @param mixed $value
+ * The value of the attribute to set.
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\ArrayObject::offsetSet()
+ */
+ public function setAttribute($name, $value): void {
+ // Handle class attribute differently.
+ if ($name === 'class') {
+ $this->removeAttribute('class');
+ $this->addClass($value);
+ }
+ else {
+ $this->offsetSet($name, $value);
+ }
+ }
+
+ /**
+ * Sets multiple attributes on the array.
+ *
+ * @param array $values
+ * An associative key/value array of attributes to set.
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\ArrayObject::merge()
+ */
+ public function setAttributes(array $values): void {
+ // Handle class attribute differently.
+ $classes = $values['class'] ?? [];
+ unset($values['class']);
+ if ($classes) {
+ $this->addClass($classes);
+ }
+
+ // Merge the reset of the attributes.
+ $this->merge($values);
+ }
+
+}
diff --git a/src/Utility/DrupalAttributes.php b/src/Utility/DrupalAttributes.php
new file mode 100644
index 0000000000000000000000000000000000000000..a8601d8659f6fdee4d849ea0607da910e4c805a8
--- /dev/null
+++ b/src/Utility/DrupalAttributes.php
@@ -0,0 +1,294 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\ui_suite_bootstrap\Utility;
+
+use Drupal\Core\Template\Attribute;
+
+/**
+ * Class for managing multiple types of attributes commonly found in Drupal.
+ */
+class DrupalAttributes extends ArrayObject {
+
+ /**
+ * Defines the "attributes" storage type constant.
+ *
+ * @var string
+ */
+ public const ATTRIBUTES = 'attributes';
+
+ /**
+ * Defines the "description_attributes" storage type constant.
+ *
+ * @var string
+ */
+ public const DESCRIPTION = 'description_attributes';
+
+ /**
+ * Defines the "input_group_attributes" storage type constant.
+ *
+ * @var string
+ */
+ public const INPUT_GROUP = 'input_group_attributes';
+
+ /**
+ * Defines the "label_attributes" storage type constant.
+ *
+ * @var string
+ */
+ public const LABEL = 'label_attributes';
+
+ /**
+ * Defines the "title_attributes" storage type constant.
+ *
+ * @var string
+ */
+ public const TITLE = 'title_attributes';
+
+ /**
+ * Defines the "wrapper_attributes" storage type constant.
+ *
+ * @var string
+ */
+ public const WRAPPER = 'wrapper_attributes';
+
+ /**
+ * Stored attribute instances.
+ *
+ * @var \Drupal\ui_suite_bootstrap\Utility\Attributes[]
+ */
+ protected $attributes = [];
+
+ /**
+ * A prefix to use for retrieving attribute keys from the array.
+ *
+ * @var string
+ */
+ protected $attributePrefix = '';
+
+ /**
+ * Add class(es) to an attributes object.
+ *
+ * This is a wrapper method to retrieve the correct attributes storage object
+ * and then add the class(es) to it.
+ *
+ * @param string|array $class
+ * An individual class or an array of classes to add.
+ * @param string $type
+ * (optional) The type of attributes to use for this method.
+ *
+ * @return $this
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::addClass()
+ */
+ public function addClass($class, $type = DrupalAttributes::ATTRIBUTES) {
+ $this->getAttributes($type)->addClass($class);
+ return $this;
+ }
+
+ /**
+ * Retrieve a specific attribute from an attributes object.
+ *
+ * This is a wrapper method to retrieve the correct attributes storage object
+ * and then retrieve the attribute from it.
+ *
+ * @param string $name
+ * The specific attribute to retrieve.
+ * @param mixed $default
+ * (optional) The default value to set if the attribute does not exist.
+ * @param string $type
+ * (optional) The type of attributes to use for this method.
+ *
+ * @return mixed
+ * A specific attribute value, passed by reference.
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::getAttribute()
+ */
+ public function &getAttribute($name, $default = NULL, $type = DrupalAttributes::ATTRIBUTES) {
+ return $this->getAttributes($type)->getAttribute($name, $default);
+ }
+
+ /**
+ * Retrieves a specific attributes object.
+ *
+ * @param string $type
+ * (optional) The type of attributes to use for this method.
+ *
+ * @return \Drupal\ui_suite_bootstrap\Utility\Attributes
+ * An attributes object for $type.
+ */
+ public function getAttributes($type = DrupalAttributes::ATTRIBUTES) {
+ if (!isset($this->attributes[$type])) {
+ $attributes = &$this->offsetGet($this->attributePrefix . $type, []);
+ if ($attributes instanceof Attribute) {
+ $attributes = $attributes->toArray();
+ }
+ $this->attributes[$type] = new Attributes($attributes);
+ }
+ return $this->attributes[$type];
+ }
+
+ /**
+ * Retrieves classes from an attributes object.
+ *
+ * This is a wrapper method to retrieve the correct attributes storage object
+ * and then retrieve the set classes from it.
+ *
+ * @param string $type
+ * (optional) The type of attributes to use for this method.
+ *
+ * @return array
+ * The classes array, passed by reference.
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::getClasses()
+ */
+ public function &getClasses($type = DrupalAttributes::ATTRIBUTES) {
+ return $this->getAttributes($type)->getClasses();
+ }
+
+ /**
+ * Indicates whether an attributes object has a specific attribute set.
+ *
+ * This is a wrapper method to retrieve the correct attributes storage object
+ * and then check there if the attribute exists.
+ *
+ * @param string $name
+ * The attribute to search for.
+ * @param string $type
+ * (optional) The type of attributes to use for this method.
+ *
+ * @return bool
+ * TRUE or FALSE
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::hasAttribute()
+ */
+ public function hasAttribute($name, $type = DrupalAttributes::ATTRIBUTES) {
+ return $this->getAttributes($type)->hasAttribute($name);
+ }
+
+ /**
+ * Indicates whether an attributes object has a specific class.
+ *
+ * This is a wrapper method to retrieve the correct attributes storage object
+ * and then check there if a class exists in the attributes object.
+ *
+ * @param string $class
+ * The class to search for.
+ * @param string $type
+ * (optional) The type of attributes to use for this method.
+ *
+ * @return bool
+ * TRUE or FALSE
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::hasClass()
+ */
+ public function hasClass($class, $type = DrupalAttributes::ATTRIBUTES) {
+ return $this->getAttributes($type)->hasClass($class);
+ }
+
+ /**
+ * Removes an attribute from an attributes object.
+ *
+ * This is a wrapper method to retrieve the correct attributes storage object
+ * and then remove an attribute from it.
+ *
+ * @param string|array $name
+ * The name of the attribute to remove.
+ * @param string $type
+ * (optional) The type of attributes to use for this method.
+ *
+ * @return $this
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::removeAttribute()
+ */
+ public function removeAttribute($name, $type = DrupalAttributes::ATTRIBUTES) {
+ $this->getAttributes($type)->removeAttribute($name);
+ return $this;
+ }
+
+ /**
+ * Removes a class from an attributes object.
+ *
+ * This is a wrapper method to retrieve the correct attributes storage object
+ * and then remove the class(es) from it.
+ *
+ * @param string|array $class
+ * An individual class or an array of classes to remove.
+ * @param string $type
+ * (optional) The type of attributes to use for this method.
+ *
+ * @return $this
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::removeClass()
+ */
+ public function removeClass($class, $type = DrupalAttributes::ATTRIBUTES) {
+ $this->getAttributes($type)->removeClass($class);
+ return $this;
+ }
+
+ /**
+ * Replaces a class in an attributes object.
+ *
+ * This is a wrapper method to retrieve the correct attributes storage object
+ * and then replace the class(es) in it.
+ *
+ * @param string $old
+ * The old class to remove.
+ * @param string $new
+ * The new class. It will not be added if the $old class does not exist.
+ * @param string $type
+ * (optional) The type of attributes to use for this method.
+ *
+ * @return $this
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::replaceClass()
+ */
+ public function replaceClass($old, $new, $type = DrupalAttributes::ATTRIBUTES) {
+ $this->getAttributes($type)->replaceClass($old, $new);
+ return $this;
+ }
+
+ /**
+ * Sets an attribute on an attributes object.
+ *
+ * This is a wrapper method to retrieve the correct attributes storage object
+ * and then set an attribute on it.
+ *
+ * @param string $name
+ * The name of the attribute to set.
+ * @param mixed $value
+ * The value of the attribute to set.
+ * @param string $type
+ * (optional) The type of attributes to use for this method.
+ *
+ * @return $this
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::setAttribute()
+ */
+ public function setAttribute($name, $value, $type = DrupalAttributes::ATTRIBUTES) {
+ $this->getAttributes($type)->setAttribute($name, $value);
+ return $this;
+ }
+
+ /**
+ * Sets multiple attributes on an attributes object.
+ *
+ * This is a wrapper method to retrieve the correct attributes storage object
+ * and then merge multiple attributes into it.
+ *
+ * @param array $values
+ * An associative key/value array of attributes to set.
+ * @param string $type
+ * (optional) The type of attributes to use for this method.
+ *
+ * @return $this
+ *
+ * @see \Drupal\ui_suite_bootstrap\Utility\Attributes::setAttributes()
+ */
+ public function setAttributes(array $values, $type = DrupalAttributes::ATTRIBUTES) {
+ $this->getAttributes($type)->setAttributes($values);
+ return $this;
+ }
+
+}
diff --git a/src/Utility/Element.php b/src/Utility/Element.php
new file mode 100644
index 0000000000000000000000000000000000000000..d65afd61cb9e6fe2999eb58b8cbd36a08c541b10
--- /dev/null
+++ b/src/Utility/Element.php
@@ -0,0 +1,574 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\ui_suite_bootstrap\Utility;
+
+use Drupal\Component\Render\FormattableMarkup;
+use Drupal\Component\Render\MarkupInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Render\Element as CoreElement;
+
+/**
+ * Provides helper methods for Drupal render elements.
+ *
+ * @see \Drupal\Core\Render\Element
+ */
+class Element extends DrupalAttributes {
+
+ /**
+ * The current state of the form.
+ *
+ * @var \Drupal\Core\Form\FormStateInterface|null
+ */
+ protected $formState;
+
+ /**
+ * {@inheritdoc}
+ */
+ protected $attributePrefix = '#';
+
+ /**
+ * Element constructor.
+ *
+ * @param array|string $element
+ * A render array element.
+ * @param \Drupal\Core\Form\FormStateInterface|null $form_state
+ * The current state of the form.
+ */
+ public function __construct(&$element = [], ?FormStateInterface $form_state = NULL) {
+ if (!\is_array($element)) {
+ $element = [
+ '#markup' => $element instanceof MarkupInterface ? $element : new FormattableMarkup($element, []),
+ ];
+ }
+ $this->array = &$element;
+ $this->formState = $form_state;
+ }
+
+ /**
+ * Magic get method.
+ *
+ * This is only for child elements, not properties.
+ *
+ * @param string $key
+ * The name of the child element to retrieve.
+ *
+ * @throws \InvalidArgumentException
+ * Throws this error when the name is a property (key starting with #).
+ *
+ * @return \Drupal\ui_suite_bootstrap\Utility\Element
+ * The child element object.
+ */
+ public function &__get($key) {
+ if (CoreElement::property($key)) {
+ throw new \InvalidArgumentException('Cannot dynamically retrieve element property. Please use \Drupal\ui_suite_bootstrap\Utility\Element::getProperty instead.');
+ }
+ return new self($this->offsetGet($key, []), $this->formState);
+ }
+
+ /**
+ * Magic set method.
+ *
+ * This is only for child elements, not properties.
+ *
+ * @param string $key
+ * The name of the child element to set.
+ * @param mixed $value
+ * The value of $name to set.
+ *
+ * @throws \InvalidArgumentException
+ * Throws this error when the name is a property (key starting with #).
+ */
+ public function __set($key, $value) {
+ if (CoreElement::property($key)) {
+ throw new \InvalidArgumentException('Cannot dynamically retrieve element property. Use \Drupal\ui_suite_bootstrap\Utility\Element::setProperty instead.');
+ }
+ $this->offsetSet($key, $value instanceof Element ? $value->getArray() : $value);
+ }
+
+ /**
+ * Magic isset method.
+ *
+ * This is only for child elements, not properties.
+ *
+ * @param string $name
+ * The name of the child element to check.
+ *
+ * @throws \InvalidArgumentException
+ * Throws this error when the name is a property (key starting with #).
+ *
+ * @return bool
+ * TRUE or FALSE
+ */
+ public function __isset($name) {
+ if (CoreElement::property($name)) {
+ throw new \InvalidArgumentException('Cannot dynamically check if an element has a property. Use \Drupal\ui_suite_bootstrap\Utility\Element::unsetProperty instead.');
+ }
+ return parent::__isset($name);
+ }
+
+ /**
+ * Magic unset method.
+ *
+ * This is only for child elements, not properties.
+ *
+ * @param mixed $name
+ * The name of the child element to unset.
+ *
+ * @throws \InvalidArgumentException
+ * Throws this error when the name is a property (key starting with #).
+ */
+ public function __unset($name) {
+ if (CoreElement::property($name)) {
+ throw new \InvalidArgumentException('Cannot dynamically unset an element property. Use \Drupal\ui_suite_bootstrap\Utility\Element::hasProperty instead.');
+ }
+ parent::__unset($name);
+ }
+
+ /**
+ * Sets the #access property on an element.
+ *
+ * @param bool|\Drupal\Core\Access\AccessResultInterface $access
+ * The value to assign to #access.
+ *
+ * @return static
+ */
+ public function access($access = NULL) {
+ return $this->setProperty('access', $access);
+ }
+
+ /**
+ * Appends a property with a value.
+ *
+ * @param string $name
+ * The name of the property to set.
+ * @param mixed $value
+ * The value of the property to set.
+ *
+ * @return static
+ */
+ public function appendProperty($name, $value) {
+ $property = &$this->getProperty($name);
+ $value = $value instanceof Element ? $value->getArray() : $value;
+
+ // If property isn't set, just set it.
+ if (!isset($property)) {
+ $property = $value;
+ return $this;
+ }
+
+ if (\is_array($property)) {
+ $property[] = Element::create($value)->getArray();
+ }
+ else {
+ $property .= (string) $value;
+ }
+
+ return $this;
+ }
+
+ /**
+ * Identifies the children of an element array, optionally sorted by weight.
+ *
+ * The children of a element array are those key/value pairs whose key does
+ * not start with a '#'. See drupal_render() for details.
+ *
+ * @param bool $sort
+ * Boolean to indicate whether the children should be sorted by weight.
+ *
+ * @return array
+ * The array keys of the element's children.
+ *
+ * @SuppressWarnings(PHPMD.BooleanArgumentFlag)
+ */
+ public function childKeys($sort = FALSE) {
+ return CoreElement::children($this->array, $sort);
+ }
+
+ /**
+ * Retrieves the children of an element array, optionally sorted by weight.
+ *
+ * The children of a element array are those key/value pairs whose key does
+ * not start with a '#'. See drupal_render() for details.
+ *
+ * @param bool $sort
+ * Boolean to indicate whether the children should be sorted by weight.
+ *
+ * @return \Drupal\ui_suite_bootstrap\Utility\Element[]
+ * An array child elements.
+ *
+ * @SuppressWarnings(PHPMD.BooleanArgumentFlag)
+ */
+ public function children($sort = FALSE) {
+ $children = [];
+ foreach ($this->childKeys($sort) as $child) {
+ $children[$child] = new self($this->array[$child]);
+ }
+ return $children;
+ }
+
+ /**
+ * Creates a new \Drupal\ui_suite_bootstrap\Utility\Element instance.
+ *
+ * @param array|string $element
+ * A render array element or a string.
+ * @param \Drupal\Core\Form\FormStateInterface|null $form_state
+ * A current FormState instance, if any.
+ *
+ * @return \Drupal\ui_suite_bootstrap\Utility\Element
+ * The newly created element instance.
+ */
+ public static function create(&$element = [], ?FormStateInterface $form_state = NULL) {
+ return $element instanceof self ? $element : new self($element, $form_state);
+ }
+
+ /**
+ * Traverses the element to find the closest button.
+ *
+ * @return \Drupal\ui_suite_bootstrap\Utility\Element|false
+ * The first button element or FALSE if no button could be found.
+ */
+ public function &findButton() {
+ $button = FALSE;
+ foreach ($this->children() as $child) {
+ if ($child->isButton()) {
+ $button = $child;
+ break;
+ }
+ $result = &$child->findButton();
+ if ($result) {
+ $button = $result;
+ break;
+ }
+ }
+ return $button;
+ }
+
+ /**
+ * Retrieves the render array for the element.
+ *
+ * @return array
+ * The element render array, passed by reference.
+ */
+ public function &getArray() {
+ return $this->array;
+ }
+
+ /**
+ * Retrieves a context value from the #context element property, if any.
+ *
+ * @param string $name
+ * The name of the context key to retrieve.
+ * @param mixed $default
+ * Optional. The default value to use if the context $name isn't set.
+ *
+ * @return mixed|null
+ * The context value or the $default value if not set.
+ */
+ public function &getContext($name, $default = NULL) {
+ $context = &$this->getProperty('context', []);
+ if (!isset($context[$name])) {
+ $context[$name] = $default;
+ }
+ return $context[$name];
+ }
+
+ /**
+ * Returns the error message filed against the given form element.
+ *
+ * Form errors higher up in the form structure override deeper errors as well
+ * as errors on the element itself.
+ *
+ * @throws \BadMethodCallException
+ * When the element instance was not constructed with a valid form state
+ * object.
+ *
+ * @return string|null
+ * Either the error message for this element or NULL if there are no errors.
+ */
+ public function getError() {
+ if (!$this->formState) {
+ throw new \BadMethodCallException('The element instance must be constructed with a valid form state object to use this method.');
+ }
+ return $this->formState->getError($this->array);
+ }
+
+ /**
+ * Retrieves the render array for the element.
+ *
+ * @param string $name
+ * The name of the element property to retrieve, not including the # prefix.
+ * @param mixed $default
+ * The default to set if property does not exist.
+ *
+ * @return mixed
+ * The property value, NULL if not set.
+ */
+ public function &getProperty($name, $default = NULL) {
+ return $this->offsetGet("#{$name}", $default);
+ }
+
+ /**
+ * Returns the visible children of an element.
+ *
+ * @return array
+ * The array keys of the element's visible children.
+ */
+ public function getVisibleChildren() {
+ return CoreElement::getVisibleChildren($this->array);
+ }
+
+ /**
+ * Indicates whether the element has an error set.
+ *
+ * @throws \BadMethodCallException
+ * When the element instance was not constructed with a valid form state
+ * object.
+ *
+ * @return bool
+ * TRUE if has error.
+ */
+ public function hasError(): bool {
+ $error = $this->getError();
+ return isset($error);
+ }
+
+ /**
+ * Indicates whether the element has a specific property.
+ *
+ * @param string $name
+ * The property to check.
+ *
+ * @return bool
+ * TRUE if has property.
+ */
+ public function hasProperty($name): bool {
+ return $this->offsetExists("#{$name}");
+ }
+
+ /**
+ * Indicates whether the element is a button.
+ *
+ * @return bool
+ * TRUE or FALSE.
+ */
+ public function isButton() {
+ $button_types = ['button', 'submit', 'reset', 'image_button'];
+ return !empty($this->array['#is_button']) || $this->isType($button_types) || $this->hasClass('btn');
+ }
+
+ /**
+ * Indicates whether the given element is empty.
+ *
+ * An element that only has #cache set is considered empty, because it will
+ * render to the empty string.
+ *
+ * @return bool
+ * Whether the given element is empty.
+ */
+ public function isEmpty() {
+ return CoreElement::isEmpty($this->array);
+ }
+
+ /**
+ * Indicates whether a property on the element is empty.
+ *
+ * @param string $name
+ * The property to check.
+ *
+ * @return bool
+ * Whether the given property on the element is empty.
+ */
+ public function isPropertyEmpty($name) {
+ return $this->hasProperty($name) && empty($this->getProperty($name));
+ }
+
+ /**
+ * Checks if a value is a render array.
+ *
+ * @param mixed $value
+ * The value to check.
+ *
+ * @return bool
+ * TRUE if the given value is a render array, otherwise FALSE.
+ */
+ public static function isRenderArray($value) {
+ return \is_array($value) && (isset($value['#type'])
+ || isset($value['#theme']) || isset($value['#theme_wrappers'])
+ || isset($value['#markup']) || isset($value['#attached'])
+ || isset($value['#cache']) || isset($value['#lazy_builder'])
+ || isset($value['#create_placeholder']) || isset($value['#pre_render'])
+ || isset($value['#post_render']) || isset($value['#process']));
+ }
+
+ /**
+ * Checks if the element is a specific type of element.
+ *
+ * @param string|array $type
+ * The element type(s) to check.
+ *
+ * @return bool
+ * TRUE if element is or one of $type.
+ */
+ public function isType($type) {
+ $property = $this->getProperty('type');
+ return $property && \in_array($property, (\is_array($type) ? $type : [$type]), TRUE);
+ }
+
+ /**
+ * Determines if an element is visible.
+ *
+ * @return bool
+ * TRUE if the element is visible, otherwise FALSE.
+ */
+ public function isVisible() {
+ return CoreElement::isVisibleElement($this->array);
+ }
+
+ /**
+ * Maps an element's properties to its attributes array.
+ *
+ * @param array $map
+ * An associative array whose keys are element property names and whose
+ * values are the HTML attribute names to set on the corresponding
+ * property; e.g., array('#property_name' => 'attribute_name'). If both
+ * names are identical except for the leading '#', then an attribute name
+ * value is sufficient and no property name needs to be specified.
+ *
+ * @return static
+ */
+ public function map(array $map) {
+ CoreElement::setAttributes($this->array, $map);
+ return $this;
+ }
+
+ /**
+ * Prepends a property with a value.
+ *
+ * @param string $name
+ * The name of the property to set.
+ * @param mixed $value
+ * The value of the property to set.
+ *
+ * @return static
+ */
+ public function prependProperty($name, $value) {
+ $property = &$this->getProperty($name);
+ $value = $value instanceof Element ? $value->getArray() : $value;
+
+ // If property isn't set, just set it.
+ if (!isset($property)) {
+ $property = $value;
+ return $this;
+ }
+
+ if (\is_array($property)) {
+ \array_unshift($property, Element::create($value)->getArray());
+ }
+ else {
+ $property = (string) $value . (string) $property;
+ }
+
+ return $this;
+ }
+
+ /**
+ * Gets properties of a structured array element (keys beginning with '#').
+ *
+ * @return array
+ * An array of property keys for the element.
+ */
+ public function properties() {
+ return CoreElement::properties($this->array);
+ }
+
+ /**
+ * Renders the final element HTML.
+ *
+ * @return \Drupal\Component\Render\MarkupInterface
+ * The rendered HTML.
+ */
+ public function render() {
+ /** @var \Drupal\Core\Render\Renderer $renderer */
+ $renderer = \Drupal::service('renderer');
+ return $renderer->render($this->array);
+ }
+
+ /**
+ * Renders the final element HTML.
+ *
+ * @return \Drupal\Component\Render\MarkupInterface
+ * The rendered HTML.
+ */
+ public function renderPlain() {
+ /** @var \Drupal\Core\Render\Renderer $renderer */
+ $renderer = \Drupal::service('renderer');
+ return $renderer->renderPlain($this->array);
+ }
+
+ /**
+ * Renders the final element HTML.
+ *
+ * (Cannot be executed within another render context.)
+ *
+ * @return \Drupal\Component\Render\MarkupInterface
+ * The rendered HTML.
+ */
+ public function renderRoot() {
+ /** @var \Drupal\Core\Render\Renderer $renderer */
+ $renderer = \Drupal::service('renderer');
+ return $renderer->renderRoot($this->array);
+ }
+
+ /**
+ * Sets the current form state for the element.
+ *
+ * @param \Drupal\Core\Form\FormStateInterface $form_state
+ * Optional. The current state of the form.
+ *
+ * @return static
+ */
+ public function setFormState(FormStateInterface $form_state) {
+ $this->formState = $form_state;
+ return $this;
+ }
+
+ /**
+ * Sets the value for a property.
+ *
+ * @param string $name
+ * The name of the property to set.
+ * @param mixed $value
+ * The value of the property to set.
+ * @param bool $recurse
+ * Flag indicating wither to set the same property on child elements.
+ *
+ * @return static
+ *
+ * @SuppressWarnings(PHPMD.BooleanArgumentFlag)
+ */
+ public function setProperty($name, $value, $recurse = FALSE) {
+ $this->array["#{$name}"] = $value instanceof Element ? $value->getArray() : $value;
+ if ($recurse) {
+ foreach ($this->children() as $child) {
+ $child->setProperty($name, $value, $recurse);
+ }
+ }
+ return $this;
+ }
+
+ /**
+ * Removes a property from the element.
+ *
+ * @param string $name
+ * The name of the property to unset.
+ *
+ * @return static
+ */
+ public function unsetProperty($name) {
+ unset($this->array["#{$name}"]);
+ return $this;
+ }
+
+}
diff --git a/src/Utility/Variables.php b/src/Utility/Variables.php
new file mode 100644
index 0000000000000000000000000000000000000000..19d5053ce8045fa6084005acd90f1227afc5a363
--- /dev/null
+++ b/src/Utility/Variables.php
@@ -0,0 +1,116 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\ui_suite_bootstrap\Utility;
+
+/**
+ * Class to help modify template variables.
+ *
+ * @ingroup utility
+ */
+class Variables extends DrupalAttributes {
+
+ /**
+ * An element object.
+ *
+ * @var \Drupal\ui_suite_bootstrap\Utility\Element|false
+ */
+ public $element = FALSE;
+
+ /**
+ * Element constructor.
+ *
+ * @param array $variables
+ * A theme hook variables array.
+ */
+ public function __construct(array &$variables) {
+ $this->array = &$variables;
+ if (isset($variables['element']) && Element::isRenderArray($variables['element'])) {
+ $this->element = Element::create($variables['element']);
+ }
+ elseif (isset($variables['elements']) && Element::isRenderArray($variables['elements'])) {
+ $this->element = Element::create($variables['elements']);
+ }
+ }
+
+ /**
+ * Creates a new \Drupal\ui_suite_bootstrap\Utility\Variables instance.
+ *
+ * @param array $variables
+ * A theme hook variables array.
+ *
+ * @return \Drupal\ui_suite_bootstrap\Utility\Variables
+ * The newly created variables instance.
+ */
+ public static function create(array &$variables) {
+ return new self($variables);
+ }
+
+ /**
+ * Retrieves a context value from the variables array or its element, if any.
+ *
+ * @param string $name
+ * The name of the context key to retrieve.
+ * @param mixed $default
+ * Optional. The default value to use if the context $name isn't set.
+ *
+ * @return mixed|null
+ * The context value or the $default value if not set.
+ */
+ public function &getContext($name, $default = NULL) {
+ $context = &$this->offsetGet($this->attributePrefix . 'context', []);
+ if (!isset($context[$name])) {
+ // If there is no context on the variables array but there is an element
+ // present, proxy the method to the element.
+ if ($this->element) {
+ return $this->element->getContext($name, $default);
+ }
+ $context[$name] = $default;
+ }
+ return $context[$name];
+ }
+
+ /**
+ * Maps an element's properties to the variables attributes array.
+ *
+ * @param array $map
+ * An associative array whose keys are element property names and whose
+ * values are the variable names to set in the variables array; e.g.,
+ * array('#property_name' => 'variable_name'). If both names are identical
+ * except for the leading '#', then an attribute name value is sufficient
+ * and no property name needs to be specified.
+ * @param bool $overwrite
+ * If the variable exists, it will be overwritten. This does not apply to
+ * attribute arrays, they will always be merged recursively.
+ *
+ * @return $this
+ *
+ * @SuppressWarnings(PHPMD.BooleanArgumentFlag)
+ */
+ public function map(array $map, $overwrite = TRUE) {
+ // Immediately return if there is no element in the variable array.
+ if (!$this->element) {
+ return $this;
+ }
+
+ // Iterate over each map item.
+ foreach ($map as $property => $variable) {
+ // If the key is numeric, the attribute name needs to be taken over.
+ if (\is_int($property)) {
+ $property = $variable;
+ }
+
+ // Merge attributes from the element.
+ if (\strpos($property, 'attributes') !== FALSE) {
+ $this->setAttributes($this->element->getAttributes($property)->getArrayCopy(), $variable);
+ }
+ // Set normal variable.
+ elseif ($overwrite || !$this->offsetExists($variable)) {
+ $this->offsetSet($variable, $this->element->getProperty($property));
+ }
+ }
+ return $this;
+ }
+
+}