Plugin: My Custom WordPress Block Style Variations

my-custom-block-variations.php

<?php
/**
 * Plugin Name: My Custom Block Variations
 * Description: Adds custom block style variations to the WordPress block editor.
 * Author: Eric Karkovack
 * Author URI: https://speckyboy.com/
 * Version: 1.0.0
 * Requires at least: 6.6
 * Requires PHP: 7.4
 */

// Don't allow direct access to the plugin file.
defined('ABSPATH') || exit;

// Custom function to register block style variations.
function mcbv_register_block_styles() {
  
  // Add block style variations here. See: https://developer.wordpress.org/block-editor/reference-guides/block-api/block-styles/#server-side-registration-helper
  
  register_block_style(
       array( 'core/button' ), // We're adding styles to the button block.
       array(
           'name'         => 'unicorn',
           'label'        => __( 'Unicorn', 'mcbv' ), // The name of our style and the plugin's text domain.
           'style_data'=> array(
                           'border' => array( // Define border styles.
                                'color' => '#9300a0',
                                'style' => 'solid',
                                'width' => '2px',
                                'radius' => '0px'
                           ),
                            'color'    => array( // Define color styles.
                                'background' => '#B516C3',
                                'gradient' => 'linear-gradient(90deg,rgba(181, 22, 195, 1) 0%, rgba(108, 22, 195, 1) 50%, rgba(22, 51, 195, 1) 100%);',
                                'text'       => '#FFFFFF',
                           ),
                           'typography'    => array( // Define typography styles.
                                'fontStyle' => 'normal',
                                'fontWeight' => 'bold'
                           ),
                    )
                )
            );
        }

// Initialize the custom function.
add_action( 'init', 'mcbv_register_block_styles' );