class-subtitle-block.php

<?php
/**
 * Subtitle Block.
 *
 * @package Newspack_Block_Theme
 */

namespace Newspack_Block_Theme;

defined( 'ABSPATH' ) || exit;


/**
 * Subtitle Block class.
 */
final class Subtitle_Block {
	const POST_META_NAME = 'newspack_post_subtitle';

	/**
	 * Initializer.
	 */
	public static function init() {
		\add_action( 'init', [ __CLASS__, 'register_block_and_post_meta' ] );
		\add_action( 'enqueue_block_assets', [ __CLASS__, 'enqueue_block_assets' ] );
	}

	/**
	 * Register the block.
	 */
	public static function register_block_and_post_meta() {
		register_block_type_from_metadata(
			__DIR__,
			[
				'render_callback' => [ __CLASS__, 'render_block' ],
			]
		);

		register_post_meta(
			'post',
			self::POST_META_NAME,
			[
				'show_in_rest' => true,
				'single'       => true,
				'type'         => 'string',
			]
		);
	}

	/**
	 * Block render callback.
	 */
	public static function render_block() {
		$post_subtitle = get_post_meta( get_the_ID(), self::POST_META_NAME, true );
		$wrapper_attributes = get_block_wrapper_attributes();
		return sprintf( '<p %1$s>%2$s</p>', $wrapper_attributes, esc_html( $post_subtitle ) );
	}

	/**
	 * Enqueue block editor subtitle assets for the appropriate editor context.
	 */
	public static function enqueue_block_assets() {
		if ( ! \wp_should_load_block_editor_scripts_and_styles() ) {
			return;
		}

		$script_data = [
			'post_meta_name' => self::POST_META_NAME,
		];

		global $pagenow;
		if ( $pagenow === 'site-editor.php' ) {
			$handle = 'newspack-block-theme-subtitle-block-site-editor';
			$asset  = require \get_theme_file_path( 'dist/subtitle-block-site-editor.asset.php' );
			\wp_enqueue_script( $handle, \get_theme_file_uri( 'dist/subtitle-block-site-editor.js' ), $asset['dependencies'], $asset['version'], true );
			\wp_localize_script( $handle, 'newspack_block_theme_subtitle_block', $script_data );
		} elseif ( \get_current_screen() && \get_current_screen()->post_type === 'post' ) {
			$handle = 'newspack-block-theme-subtitle-block-post-editor';
			$asset  = require \get_theme_file_path( 'dist/subtitle-block-post-editor.asset.php' );
			\wp_enqueue_script( $handle, \get_theme_file_uri( 'dist/subtitle-block-post-editor.js' ), $asset['dependencies'], $asset['version'], true );
			\wp_localize_script( $handle, 'newspack_block_theme_subtitle_block', $script_data );
		}
	}
}
Subtitle_Block::init();