advanced_environment_indicator.php

<?php
/*
Plugin Name: Advanced environment indicator
Version: 0.1-alpha
Description: This plugin shows the environment name (dev || staging || prod) int he Woerpress toolbar, to avoid editing the wrong environment.
Author: Patrick van Efferen
Author URI: http://patrickvanefferen.nl
License: GPLv2 or later
Text Domain: advanced_environment_indicator
Domain Path: /languages
*/

/*
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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

/**
 * Read environment name from wp-settings.php and show in Toolbar
 */
function advanced_environment_indicator_toolbar() {
  global $wp_admin_bar;
  $args = array(
    'id' => 'advanced_environment_indicator',
    'title' => esc_attr(ADVANCED_ENVIRONMENT_INDICATOR_NAME),
  );

  $wp_admin_bar->add_node($args);
}

// Hook into the 'wp_before_admin_bar_render' action
add_action( 'wp_before_admin_bar_render', 'advanced_environment_indicator_toolbar', 999 );

/**
 * Add styling for Advanced environment indicator to DOM
 */
function advanced_environment_indicator_style() {
  $color = esc_attr(ADVANCED_ENVIRONMENT_INDICATOR_COLOR);
  $style = "<style>
     #wp-admin-bar-advanced_environment_indicator {
            background-color: {$color} !important;
          }</style>";
  echo $style;
}

add_action( 'admin_head', 'advanced_environment_indicator_style' );

?>