Allows for a custom post detail page in WordPress

functions.php

<?php
// Allows for a custom post detail page
add_action('init', 'hm_alternative_post_page');
function alternative_post_page() {
  add_rewrite_rule('story/([^/]+)/?$', 'index.php?page_id=13317&child_post_name=$matches[1]', 'top');
}

// Setup our custom `child_post_slug` query var for custom post detail pages
add_filter('query_vars', 'alternative_post_page_var');
function hm_alternative_post_page_var($vars) {
  $vars[] = 'child_post_name';
  return $vars;
}

// Setup child post data for custom post detail page or display 404 template if post isn't found
function setup_child_postdata() {
  $child_post_query = new WP_Query(array(
    'fields'        => 'ids',
    'name'          => get_query_var('child_post_name'),
    'no_found_rows' => true,
    'numberposts'   => 1,
    'post_type'     => 'story'
  ));

  $child_post = array_shift($child_post_query->get_posts());

  if (!count($child_post)) {
    global $wp_query;
    $wp_query->set_404();
    status_header(404);
    get_template_part(404);
    exit();
  }

  setup_postdata($GLOBALS['post'] =& $child_post);
}
?>

template-story.php

<?php /* Template Name: Story Details */ ?>
<?php get_header(); ?>
<?php
// Store data from parent page
$parent_page_title = get_the_title();
?>
<?php setup_child_postdata(); ?>

<section>
  <h1><?php the_title(); ?></h1>
  <h2><?=$parent_page_title?></h2>
  <?php the_content(); ?>
</section>

<?php
// Get template part with parent page data
global $wp_query;
setup_postdata($GLOBALS['post'] =& array_shift($wp_query->get_posts()));
get_template_part('templates/inc', 'sections');
?>

<?php get_footer(); ?>