iw-2em.php

<?php
/*
Plugin Name: 2em
Plugin URI: https://wordpress.org/plugins/2em/
Description: add "text-indent:2em" support to editor.
Version: 1.1.0
Author: hewei
Author URI: http://blog.itfsw.com
License: GPL2+
*/

/*
    Copyright Automattic and many other contributors.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

if ( is_admin() ) {

	/**
	 * add plugin
	 *
	 * @param $plugin_array
	 *
	 * @return mixed
	 */
	function iw_add_plugin( $plugin_array ) {
		$plugin_array['iw_2em'] = plugins_url( 'res/js/iw-2em.js', __FILE__ );

		return $plugin_array;
	}

	add_filter( 'mce_external_plugins', 'iw_add_plugin' );

	/**
	 * register buttons
	 *
	 * @param $buttons
	 *
	 * @return mixed
	 */
	function iw_register_buttons( $buttons ) {
		array_push( $buttons, 'separator', 'iw_2em' );

		return $buttons;
	}

	add_filter( 'mce_buttons', 'iw_register_buttons' );


	/**
	 * Enqueue Gutenberg block assets for backend editor.
	 */
	function iw_2em_enqueue_block_editor_assets() {
		// js
		wp_enqueue_script( 'iw-2em-plugin-js', plugins_url( 'build/index.js', __FILE__ ), array( 'wp-block-library' ) );
	}

	add_action( 'enqueue_block_editor_assets', 'iw_2em_enqueue_block_editor_assets' );
}

/**
 * 注册block 样式
 */
function iw_2em_enqueue_block_assets() {
	wp_enqueue_style( 'iw-2em-plugin-css',  plugins_url( 'res/css/index.css', __FILE__ ));
}
add_action( 'enqueue_block_assets', 'iw_2em_enqueue_block_assets' );