/index.php

<?php 
/** 
Plugin Name: Google Books Importer 
Plugin URI: https://firescripts.net 
Description: Bulk import of books from Google Books 
Version: 1.3 
Author: Zarko 
Author URI: https://firescripts.net 
License: GPLv3 
*/ 
 
define('GBI_PATH', dirname(__FILE__)); 
define('GBI_URL', plugin_dir_url(__FILE__)); 
 
add_action('admin_menu', 'gbi_register_submenu_page'); 
add_action('admin_init', 'gbi_register_resources'); 
add_action('admin_init', 'gbi_default_setup'); 
 
include('inc/functions.php'); 
 
function gbi_register_submenu_page() { 
  add_menu_page('Google Books Importer', 'GB Import', 'manage_options', 'google-books-importer', 'gbi_admin_pages', 'dashicons-book-alt'); 
  add_submenu_page( 'google-books-importer', 'Google Books Importer Settings', 'GB Settings', 'manage_options', 'google-books-settings', 'gbi_admin_pages');  
} 
 
function gbi_admin_pages() {  
  require_once(GBI_PATH.'/admin.php'); 
} 
 
// include resources 
function gbi_register_resources() {  
  if(isset($_GET['page']) && ($_GET['page'] == 'google-books-importer' || $_GET['page'] == 'google-books-settings')) {  
      wp_enqueue_style('gbi-style', GBI_URL.'assets/style.css'); 
      wp_enqueue_script('gbi-script', GBI_URL.'assets/scripts.js', array('jquery')); 
  } 
} 
 
function gbi_default_setup() {  
   
  if(get_option('gbi_fields')) 
      return; 
 
  // default setup 
  $mapped_fields = array(  
      'post_title' => 'title',  
      'post_content' => 'description',  
      'post_excerpt' => 'subtitle',  
      'post_status' => 'publish',  
      'comment_status' => 'open',  
      'post_types' => 'post',  
      'category' => '0',  
      'featured' => '0',  
 ); 
 
  update_option('gbi_fields', $mapped_fields); 
  update_option('gbi_apikey', ''); 
 
}