plugin.php

<?php
/**
 * Plugin Name: WP Projects
 * Plugin URI:  https://github.com/anisur2805/wp-projects
 * Description: WP Projects is for showcase custom post type
 * Version:     1.0.0
 * Author:      Anisur Rahman
 * Author URI:  https://github.com/anisur2805
 * Text Domain: wp-projects
 * Domain Path: /languages/
 * License:     GPL-2.0+
 * License URI: http://www.gnu.org/licenses/gpl-2.0.txt
 *
 */

use WP\Projects\Ajax;
use WP\Projects\Installer;

// Exit if accessed directly.
defined( 'ABSPATH' ) || exit;

require_once __DIR__ . '/vendor/autoload.php';

final class WP_Projects {
	/**
	 * plugin version
	 */
	const VERSION = '1.0';

	/**
	 * class constructor
	 */
	private function __construct() {
		$this->define_constants();

		register_activation_hook( __FILE__, array( $this, 'activate' ) );
		add_action( 'plugins_loaded', array( $this, 'init_plugin' ) );
	}

	/**
	 * Initialize a singleton instance
	 *
	 * @return \WP_Projects
	 */
	public static function init() {
		static $instance = false;
		if ( ! $instance ) {
			$instance = new self();
		}

		return $instance;
	}

	/**
	 * define plugin require constants
	 *
	 * @return void
	 */
	public function define_constants() {
        // @codingStandardsIgnoreStart
		define( 'WP_Projects_VERSION', self::VERSION );
		define( 'WP_Projects_FILE', __FILE__ );
		define( 'WP_Projects_PATH', __DIR__ );
		define( 'WP_Projects_URL', plugins_url( '', WP_Projects_FILE ) );
		define( 'WP_Projects_ASSETS', WP_Projects_URL . '/assets' );
		define( 'WP_Projects_INCLUDES', WP_Projects_URL . '/includes' );
        // @codingStandardsIgnoreEnd
	}

	/**
	 * Do staff upon plugin activation
	 *
	 * @return void
	 */
	public function activate() {
		$installer = new Installer();
		$installer->run();
	}

	public function init_plugin() {

		/**
		 * Load Assets
		 */
		new WP\Projects\Assets();

		if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
			new Ajax();
		}

		/**
		 * Load Admin Class
		 */
		if ( is_admin() ) {
			new \WP\Projects\Admin();
		} else {
			new \WP\Projects\Frontend();
		}
	}
}

/**
 * Initialize the main plugin
 *
 * @return \WP_Projects
 */
function wp_projects() {
	return WP_Projects::init();
}

wp_projects();