alpual_ShortCodeLoader.php

<?php
/*
    "WordPress Plugin Template" Copyright (C) 2017 Michael Simpson  (email : michael.d.simpson@gmail.com)

    This file is part of WordPress Plugin Template for WordPress.

    WordPress Plugin Template 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 3 of the License, or
    (at your option) any later version.

    WordPress Plugin Template 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 Contact Form to Database Extension.
    If not, see http://www.gnu.org/licenses/gpl-3.0.html
*/

abstract class alpual_ShortCodeLoader {

    /**
     * @param  $shortcodeName mixed either string name of the shortcode
     * (as it would appear in a post, e.g. [shortcodeName])
     * or an array of such names in case you want to have more than one name
     * for the same shortcode
     * @return void
     */
    public function register($shortcodeName) {
        $this->registerShortcodeToFunction($shortcodeName, 'handleShortcode');
    }

    /**
     * @param  $shortcodeName mixed either string name of the shortcode
     * (as it would appear in a post, e.g. [shortcodeName])
     * or an array of such names in case you want to have more than one name
     * for the same shortcode
     * @param  $functionName string name of public function in this class to call as the
     * shortcode handler
     * @return void
     */
    protected function registerShortcodeToFunction($shortcodeName, $functionName) {
        if (is_array($shortcodeName)) {
            foreach ($shortcodeName as $aName) {
                add_shortcode($aName, array($this, $functionName));
            }
        }
        else {
            add_shortcode($shortcodeName, array($this, $functionName));
        }
    }

    /**
     * @abstract Override this function and add actual shortcode handling here
     * @param  $atts shortcode inputs
     * @return string shortcode content
     */
    public abstract function handleShortcode($atts);

}