block-bindings.php

<?php
/**
 * Plugin Name: Gutenberg Test Block Bindings
 * Plugin URI: https://github.com/WordPress/gutenberg
 * Author: Gutenberg Team
 *
 * @package gutenberg-test-block-bindings
 */

/**
* Register custom fields and custom block bindings sources.
*/
function gutenberg_test_block_bindings_registration() {
	// Register custom block bindings sources.
	register_block_bindings_source(
		'core/server-source',
		array(
			'label'              => 'Server Source',
			'get_value_callback' => function () {},
		)
	);

	// Register custom fields.
	register_meta(
		'post',
		'text_custom_field',
		array(
			'show_in_rest' => true,
			'type'         => 'string',
			'single'       => true,
			'default'      => 'Value of the text custom field',
		)
	);
	register_meta(
		'post',
		'url_custom_field',
		array(
			'show_in_rest' => true,
			'type'         => 'string',
			'single'       => true,
			'default'      => '#url-custom-field',
		)
	);
	register_meta(
		'post',
		'empty_field',
		array(
			'show_in_rest' => true,
			'type'         => 'string',
			'single'       => true,
			'default'      => '',
		)
	);
	register_meta(
		'post',
		'_protected_field',
		array(
			'type'    => 'string',
			'single'  => true,
			'default' => 'protected field value',
		)
	);
	register_meta(
		'post',
		'show_in_rest_false_field',
		array(
			'show_in_rest' => false,
			'type'         => 'string',
			'single'       => true,
			'default'      => 'show_in_rest false field value',
		)
	);
}
add_action( 'init', 'gutenberg_test_block_bindings_registration' );