Follow these steps to create a custom archive page for the book post type in order to understand the use of WordPress Loop:

1. Open the WPCookbook Chapter 7 plugin using the file explorer.
2. Create a new file called archive_books.php inside the WPCookbook Chapter 7 plugin.
3. Add the following code block for the archive template:

<?php
get_header();
?>

 <section id="primary" class="content-area">
 <main id="main" class="site-main"> 
 <!-- Step 4 code should be placed in the next line -->

 </main><!-- #main -->
 </section><!-- #primary -->

<?php
get_footer();

4. Add the following code clock within the opening and closing <main> tags to display books details:

<?php 
   if ( have_posts() ) : ?>
   <header class="page-header" style="text-align: center;
    font-size: 60px;">
   <?php echo __('Book List','wpccp_ch7'); ?>
   </header> 
   <?php
   while ( have_posts() ) : the_post();
   ?>
     <div style="margin:30px auto;width:80%;
      background: #afc8e2;padding: 10px"> 
     <div style="text-align: center;text-align: center;
      font-size: 25px;font-weight: bold;" ><?php the_title(); 
      ?></div>
     <div><?php the_content(); ?></div>
     </div>

   <?php
   endwhile;

   endif;
  ?>
<?php get_template_part( 'template-parts/pagination' ); ?>

5. Add the following code to the end of the wpcookbookchapter7.php file to use the custom archive_books.php template for the book archive page:

add_filter('template_include', 'wpccp_chapter7_book_list_template');
function wpccp_chapter7_book_list_template( $template ) {
 if ( is_post_type_archive('book') ) {
 return plugin_dir_path(__FILE__) . 'archive_books.php';
 }
 return $template;
}

6. Save the changes to file.

Now, go to the frontend of the site and access the book list. The book list can be accessed by using the http://www.yoursite.com/book/ URL. Replace www.yoursite.com with the URL of your site. You will see a customized book list, as shown in the following screenshot:

The custom design contains a title and content with a custom background color, instead of the default post design.