Add `TAttributeFormField`

diff --git a/wcfsetup/install/files/lib/system/form/builder/field/TAttributeFormField.class.php b/wcfsetup/install/files/lib/system/form/builder/field/TAttributeFormField.class.php
new file mode 100644 (file)
index 0000000..74dee7f
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/form/builder/field/TAttributeFormField.class.php
@@ -0,0 +1,139 @@
+<?php
+namespace wcf\system\form\builder\field;
+use wcf\system\form\builder\IFormNode;
+
+/**
+ * Provides default implementations of `IAttributeFormField` methods.
+ *
+ * @author      Matthias Schmidt
+ * @copyright   2001-2020 WoltLab GmbH
+ * @license     GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package     WoltLabSuite\Core\System\Form\Builder\Field
+ * @since       5.4
+ */
+trait TAttributeFormField {
+       /**
+        * @var?string[]
+        */
+       protected $fieldAttributes = [];
+       
+       /**
+        * @var string[]
+        */
+       protected static $interfaceToFieldAttributeMap = [
+               IAutoFocusFormField::class => 'autofocus',
+               IAutoCompleteFormField::class => 'autocomplete',
+               IImmutableFormField::class => 'disabled',
+               IInputModeFormField::class => 'inputmode',
+               IMaximumFormField::class => 'max',
+               IMaximumLengthFormField::class => 'maxlength',
+               IMinimumFormField::class => 'min',
+               IMinimumLengthFormField::class => 'minlength',
+               IPatternFormField::class => 'pattern',
+               IPlaceholderFormField::class => 'placeholder',
+       ];
+       
+       /**
+        * Returns the value of the additional attribute of the actual field element with the given name.
+        *
+        * @throws      \InvalidArgumentException       if the given attribute is invalid or no such attribute exists
+        */
+       public function getFieldAttribute(string $name): self {
+               if (!$this->hasFieldAttribute($name)) {
+                       throw new \InvalidArgumentException("Unknown attribute '{$name}' requested.");
+               }
+               
+               return $this->fieldAttributes[$name];
+       }
+       
+       /**
+        * Returns all additional attributes of the actual field element.
+        */
+       public function getFieldAttributes(): array {
+               return $this->fieldAttributes;
+       }
+       
+       /**
+        * Adds the given additional attribute to the actual field element and returns this field.
+        *
+        * @throws      \InvalidArgumentException       if the given attribute is invalid
+        */
+       public function fieldAttribute(string $name, string $value = null): self {
+               static::validateFieldAttribute($name);
+               
+               $this->fieldAttributes[$name] = $value;
+               
+               return $this;
+       }
+       
+       /**
+        * Returns `true` if an additional attribute of the actual field element with the given name exists and returns
+        * false` otherwise.
+        *
+        * @throws      \InvalidArgumentException       if the given attribute is invalid
+        */
+       public function hasFieldAttribute(string $name): bool {
+               static::validateFieldAttribute($name);
+               
+               return isset($this->fieldAttributes[$name]);
+       }
+       
+       /**
+        * Removes the given additional attribute of the actual field element and returns this field.
+        *
+        * If the actual field element does not have the given attribute, this method silently ignores that fact.
+        *
+        * @throws      \InvalidArgumentException       if the given attribute is invalid
+        */
+       public function removeFieldAttribute(string $name): self {
+               static::validateFieldAttribute($name);
+               
+               unset($this->fieldAttributes[$name]);
+               
+               return $this;
+       }
+       
+       /**
+        * Returns a list of attributes that are not accessible via the field attribute methods.
+        * 
+        * @return      string[]
+        */
+       protected static function getReservedFieldAttributes(): array {
+               $attributes = [
+                       'class',
+                       'id',
+                       'required',
+               ];
+               
+               foreach (static::$interfaceToFieldAttributeMap as $interface => $attribute) {
+                       if (is_subclass_of(static::class, $interface)) {
+                               $attributes[] = $attribute;
+                       }
+               }
+               
+               return $attributes;
+       }
+       
+       /**
+        * Checks if the given name is valid attribute name.
+        *
+        * @param       string          $name           checked argument name
+        *
+        * @throws      \InvalidArgumentException       if the given attribute name is invalid
+        * @see         IFormNode::validateAttribute()
+        */
+       abstract public static function validateAttribute($name);
+       
+       /**
+        * Checks if the given name is a valid additional attribute name.
+        *
+        * @throws      \InvalidArgumentException       if the given additional attribute name is invalid
+        */
+       public static function validateFieldAttribute(string $name) {
+               static::validateAttribute($name);
+               
+               if (in_array(strtolower($name), static::getReservedFieldAttributes())) {
+                       throw new \InvalidArgumentException("Attribute '{$name}' is not accessible as a field attribute.");
+               }
+       }
+}