ultimatemember/includes/core/class-fonticons.php

<?php
namespace um\core;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

if ( ! class_exists( 'um\core\FontIcons' ) ) {

	/**
	 * Class FontIcons
	 * @package um\core
	 */
	class FontIcons {

		/**
		 * The list of the FontIcons.
		 *
		 * @var array
		 */
		public $all = array();

		/**
		 * FontIcons constructor.
		 */
		public function __construct() {
			$cached_option = get_option( 'um_cache_fonticons', array() );

			if ( empty( $cached_option ) ) {
				$files['ii'] = UM_PATH . 'assets/libs/legacy/fonticons/fonticons-ii.css';
				$files['fa'] = UM_PATH . 'assets/libs/legacy/fonticons/fonticons-fa.css';

				$array = array();
				foreach ( $files as $c => $file ) {
					$css = file_get_contents( $file );

					if ( 'fa' === $c ) {
						preg_match_all( '/\.(um-faicon-.*?):before/', $css, $matches );
					} else {
						preg_match_all( '/\.(um-icon-.*?):before/', $css, $matches );
					}

					foreach ( $matches[1] as $match ) {
						$icon    = str_replace( ':before', '', $match );
						$array[] = $icon;
					}
					$array = array_unique( $array );
				}

				update_option( 'um_cache_fonticons', $array );
			}

			$this->all = $cached_option;
		}
	}
}