Code to needed to build a WP block, at least the php portion. Good way to convert WP Shortcodes

build-a-block-with-php.php

<?php

defined( 'ABSPATH' ) || die( 'File cannot be accessed directly' );

function built_with_php_init() {
	// Register our block editor script.
	wp_enqueue_script(
		'built-with-php',
		plugins_url( 'block.js', __FILE__ ),
		array( 'wp-blocks', 'wp-element', 'wp-components', 'wp-editor' )
	);
	register_block_type(
		'wclancpa-2019/built-with-php',
		array(
			'attributes'      =>
			array(
				'value_one'   => array(
					'type'    => 'string',
					'default' => 'A simple text box',
				),
				'value_two'   => array(
					'type'    => 'string',
					'default' => 'Ain\'t this purdy?',
				),
				'value_three' => array(
					'type'    => 'string',
					'default' => 'This will be more of a description.... And I could go on and on...',
				),
			),
			// The script name we gave in the wp_register_script() call.
			'editor_script'   => 'built-with-php',
			'render_callback' => 'built_with_php_render',
		)
	);

	add_shortcode( 'built-with-php-shortcode', 'built_with_php_render' );
}
add_action( 'init', 'built_with_php_init' );

function built_with_php_render( $attributes ) {
	$return  = '<h2 style="color:salmon;">' . ( print_r( $attributes['value_one'], true ) ?: 'value_one not defined' ) . '</h2>';
	$return .= '<h4>' . print_r( $attributes['value_two'], true ) . '</h4>';
	$return .= '<p>' . print_r( $attributes['value_three'], true ) . '</p>';
	return $return;
}