Converts/Refactor all AJAX calls to WP Rest API Calls

src/Api/V1/Base_Api.php

@@ -0,0 +1,96 @@
+<?php
+
+namespace GFPDF\Api\V1;
+
+use GFPDF\Helper\Helper_Trait_Logger;
+
+/**
+ * @package     Gravity PDF
+ * @copyright   Copyright (c) 2019, Blue Liquid Designs
+ * @license     http://opensource.org/licenses/gpl-2.0.php GNU Public License
+ * @since       5.2
+ */
+
+/* Exit if accessed directly */
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/*
+	This file is part of Gravity PDF.
+
+	Gravity PDF – Copyright (c) 2019, Blue Liquid Designs
+
+	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
+*/
+
+/**
+ * Class Base_Api
+ *
+ * @package GFPDF\Api\V1
+ *
+ * @since 5.2
+ */
+abstract class Base_Api {
+
+	/**
+	 * @since 5.2
+	 */
+	use Helper_Trait_Logger;
+
+	/**
+	 * @since 5.2
+	 */
+	const ENTRYPOINT = 'gravity-pdf';
+
+	/**
+	 * @since 5.2
+	 */
+	const VERSION = 'v1';
+
+	/**
+	 * Initialise our endpoint
+	 *
+	 * @since 5.2
+	 */
+	public function init() {
+		add_action( 'rest_api_init', [ $this, 'register' ] );
+	}
+
+	/**
+	 * Simple wrapper to check the current user's capabilities in the context of Gravity Forms
+	 *
+	 * @param string $capability
+	 *
+	 * @return bool
+	 *
+	 * @since 5.2
+	 */
+	public function has_capabilities( $capability ) {
+		$gform = \GPDFAPI::get_form_class();
+		return $gform->has_capability( $capability );
+	}
+
+	/**
+	 * Register WordPress REST API endpoint(s)
+	 *
+	 * @return void
+	 *
+	 * @internal Use `register_rest_route()` to register WordPress REST API endpoint(s)
+	 *
+	 * @since 5.2
+	 */
+	abstract public function register();
+}