1<?php
  2/**
  3 * Block support flags.
  4 *
  5 * @package WordPress
  6 *
  7 * @since 5.6.0
  8 */
  9
 10/**
 11 * Class encapsulating and implementing Block Supports.
 12 *
 13 * @since 5.6.0
 14 *
 15 * @access private
 16 */
 17#[AllowDynamicProperties]
 18class WP_Block_Supports {
 19
 20	/**
 21	 * Config.
 22	 *
 23	 * @since 5.6.0
 24	 * @var array
 25	 */
 26	private $block_supports = array();
 27
 28	/**
 29	 * Tracks the current block to be rendered.
 30	 *
 31	 * @since 5.6.0
 32	 * @var array
 33	 */
 34	public static $block_to_render = null;
 35
 36	/**
 37	 * Container for the main instance of the class.
 38	 *
 39	 * @since 5.6.0
 40	 * @var WP_Block_Supports|null
 41	 */
 42	private static $instance = null;
 43
 44	/**
 45	 * Utility method to retrieve the main instance of the class.
 46	 *
 47	 * The instance will be created if it does not exist yet.
 48	 *
 49	 * @since 5.6.0
 50	 *
 51	 * @return WP_Block_Supports The main instance.
 52	 */
 53	public static function get_instance() {
 54		if ( null === self::$instance ) {
 55			self::$instance = new self();
 56		}
 57
 58		return self::$instance;
 59	}
 60
 61	/**
 62	 * Initializes the block supports. It registers the block supports block attributes.
 63	 *
 64	 * @since 5.6.0
 65	 */
 66	public static function init() {
 67		$instance = self::get_instance();
 68		$instance->register_attributes();
 69	}
 70
 71	/**
 72	 * Registers a block support.
 73	 *
 74	 * @since 5.6.0
 75	 *
 76	 * @link https://developer.wordpress.org/block-editor/reference-guides/block-api/block-supports/
 77	 *
 78	 * @param string $block_support_name   Block support name.
 79	 * @param array  $block_support_config Array containing the properties of the block support.
 80	 */
 81	public function register( $block_support_name, $block_support_config ) {
 82		$this->block_supports[ $block_support_name ] = array_merge(
 83			$block_support_config,
 84			array( 'name' => $block_support_name )
 85		);
 86	}
 87
 88	/**
 89	 * Generates an array of HTML attributes, such as classes, by applying to
 90	 * the given block all of the features that the block supports.
 91	 *
 92	 * @since 5.6.0
 93	 *
 94	 * @return string[] Array of HTML attribute values keyed by their name.
 95	 */
 96	public function apply_block_supports() {
 97		$block_type = WP_Block_Type_Registry::get_instance()->get_registered(
 98			self::$block_to_render['blockName']
 99		);
100
101		// If no render_callback, assume styles have been previously handled.
102		if ( ! $block_type || empty( $block_type ) ) {
103			return array();
104		}
105
106		$block_attributes = array_key_exists( 'attrs', self::$block_to_render ) && is_array( self::$block_to_render['attrs'] )
107			? $block_type->prepare_attributes_for_render( self::$block_to_render['attrs'] )
108			: array();
109
110		$output = array();
111		foreach ( $this->block_supports as $block_support_config ) {
112			if ( ! isset( $block_support_config['apply'] ) ) {
113				continue;
114			}
115
116			$new_attributes = call_user_func(
117				$block_support_config['apply'],
118				$block_type,
119				$block_attributes
120			);
121
122			if ( ! empty( $new_attributes ) ) {
123				foreach ( $new_attributes as $attribute_name => $attribute_value ) {
124					if ( empty( $output[ $attribute_name ] ) ) {
125						$output[ $attribute_name ] = $attribute_value;
126					} else {
127						$output[ $attribute_name ] .= " $attribute_value";
128					}
129				}
130			}
131		}
132
133		return $output;
134	}
135
136	/**
137	 * Registers the block attributes required by the different block supports.
138	 *
139	 * @since 5.6.0
140	 */
141	private function register_attributes() {
142		$block_registry         = WP_Block_Type_Registry::get_instance();
143		$registered_block_types = $block_registry->get_all_registered();
144		foreach ( $registered_block_types as $block_type ) {
145			if ( ! ( $block_type instanceof WP_Block_Type ) ) {
146				continue;
147			}
148			if ( ! $block_type->attributes ) {
149				$block_type->attributes = array();
150			}
151
152			foreach ( $this->block_supports as $block_support_config ) {
153				if ( ! isset( $block_support_config['register_attribute'] ) ) {
154					continue;
155				}
156
157				call_user_func(
158					$block_support_config['register_attribute'],
159					$block_type
160				);
161			}
162		}
163	}
164}
165
166/**
167 * Generates a string of attributes by applying to the current block being
168 * rendered all of the features that the block supports.
169 *
170 * @since 5.6.0
171 *
172 * @param string[] $extra_attributes Optional. Array of extra attributes to render on the block wrapper.
173 * @return string String of HTML attributes.
174 */
175function get_block_wrapper_attributes( $extra_attributes = array() ) {
176	$new_attributes = WP_Block_Supports::get_instance()->apply_block_supports();
177
178	if ( empty( $new_attributes ) && empty( $extra_attributes ) ) {
179		return '';
180	}
181
182	// This is hardcoded on purpose.
183	// We only support a fixed list of attributes.
184	$attributes_to_merge = array( 'style', 'class', 'id', 'aria-label' );
185	$attributes          = array();
186	foreach ( $attributes_to_merge as $attribute_name ) {
187		if ( empty( $new_attributes[ $attribute_name ] ) && empty( $extra_attributes[ $attribute_name ] ) ) {
188			continue;
189		}
190
191		if ( empty( $new_attributes[ $attribute_name ] ) ) {
192			$attributes[ $attribute_name ] = $extra_attributes[ $attribute_name ];
193			continue;
194		}
195
196		if ( empty( $extra_attributes[ $attribute_name ] ) ) {
197			$attributes[ $attribute_name ] = $new_attributes[ $attribute_name ];
198			continue;
199		}
200
201		$attributes[ $attribute_name ] = $extra_attributes[ $attribute_name ] . ' ' . $new_attributes[ $attribute_name ];
202	}
203
204	foreach ( $extra_attributes as $attribute_name => $value ) {
205		if ( ! in_array( $attribute_name, $attributes_to_merge, true ) ) {
206			$attributes[ $attribute_name ] = $value;
207		}
208	}
209
210	if ( empty( $attributes ) ) {
211		return '';
212	}
213
214	$normalized_attributes = array();
215	foreach ( $attributes as $key => $value ) {
216		$normalized_attributes[] = $key . '="' . esc_attr( $value ) . '"';
217	}
218
219	return implode( ' ', $normalized_attributes );
220}
221