single.php

<?php
/**
 * The template for displaying all single posts
 *
 * @link https://developer.wordpress.org/themes/basics/template-hierarchy/#single-post
 *
 * @package Milors
 */
get_header();

global $post;
$author_id = $post->post_author;
$header_excerpt = apply_filters('the_excerpt', get_the_excerpt($post));
$sidebar = get_post_meta( get_the_ID(), '_milors_sidebar', true ); 
$headerStyle = get_post_meta( get_the_ID(), '_milors_single_post_header', true );

?>

<?php if ($headerStyle == 'bigimgwithtitleHeader') : ?>
<div class="article-style-four mb-5">
  	<div class="article-header article-header-img-overlay">
		<?php 
			$img =  wp_get_attachment_image_src( get_post_thumbnail_id(get_the_ID()), 'large-height-fixed', false, '' );
				if ( $img != '' ) : 
		?>

		<div class="img-post-thumb img-fluid mx-auto d-block" style="background-image: url('<?php echo esc_url($img[0]); ?>')"></div>

		<div class="entry-content">
			<span class="post-category">
				<?php the_category() ?>
			</span>

			<h1 class="entry-title pt-1"><?php the_title(); ?></h1>

			<div class="entry-meta">
				<span class="author vcard">
				<span>By</span><?php echo nl2br(get_the_author_meta('display_name', $author_id)); ?>
				</span>
				<span class="posted-on line">
				<span>On</span><time class="entry-date published"
					datetime="<?php the_time("M j, Y");?>"><?php the_time("M j, Y");?></time>
				</span>
			</div>

		</div>

    <?php endif; ?>
  </div>
</div>

<?php endif; ?>

<?php if ( $sidebar == 'no-sidebar' ) : ?>
<div id="primary" class="no-sidebar container py-md-5 py-lg-5">
  <?php else : ?>
  <div id="primary" class="container py-md-5 py-lg-5">
    <?php endif; ?>

    <?php if ($headerStyle == 'bigimgHeader') : ?>
    <div class="post-media post-image mb-5">
      <?php $img =  wp_get_attachment_image_src( get_post_thumbnail_id(get_the_ID()), 'large-height-fixed', false, '' ); ?>
      <img src="<?php echo esc_url($img[0]); ?>" alt="<?php the_title_attribute(); ?>"
        class="img-fluid img-fluid mx-auto d-block">
    </div>

    <?php elseif ($headerStyle == 'leftHeader') : ?>

    <div class="article-style-three pt-2 pb-5 mb-5">
      <div class="wrap no-gutters row">
        <div class="d-flex align-content-center flex-wrap col-md-5 col-sm-12 col-12 py-5 py-md-0 py-lg-0 py-xl-0 pr-5">
          <h1 class="entry-title"><?php the_title(); ?></h1>
          <span class="tagging line"><?php the_category(); ?></span>

          <?php echo $header_excerpt; ?>

          <div class="post-author">
            <div class="post-author-avatar">
              <?php  
	                                $user_id = get_the_author_meta('ID', $author_id);
	                                echo get_avatar( $user_id, 35 ); 
	                            ?>
            </div>
            <div class="post-author-name">
              <a
                href="<?php echo get_author_posts_url( get_the_author_meta( 'ID',  $author_id ), get_the_author_meta( 'user_nicename', $author_id ) ); ?>">
                <?php echo nl2br(get_the_author_meta('display_name', $author_id)); ?>
              </a>

              <br>
              <time class="entry-date" datetime="<?php the_time("M j, Y");?>"><?php the_time("M j, Y");?></time>
            </div>
          </div>
        </div>
        <div class="col-md-7 col-sm-12 col-12">
          <?php $img =  wp_get_attachment_image_src( get_post_thumbnail_id(get_the_ID()), 'fullsize', false, '' ); ?>

          <img src="<?php echo esc_url($img[0]); ?>" class="img-fluid" alt="<?php the_title_attribute(); ?>">
        </div>
      </div>
    </div>

    <?php endif; ?>


    <div class="row">

      <?php if ( $sidebar === 'rightSidebar' ) { ?>

      <div class="col-md-8 col-lg-8 col-xl-8 col-sm-12 pr-5">

        <?php
				while ( have_posts() ) :
					the_post();

					get_template_part( 'template-parts/content', get_post_type() );

					milors_author_bio();

					// calling related post function 
					milors_related_post(array(
						'taxonomy' => 'category',
						'limit' => 6
					)); 

					// If comments are open or we have at least one comment, load up the comment template.
					if ( comments_open() || get_comments_number() ) :
						comments_template();
					endif;

				endwhile; // End of the loop.
				?>

      </div>

      <div class="col-md-4 col-lg-4 col-xl-4 col-sm-12 widgets-no-padding">
        <?php get_sidebar(); ?>
      </div>

      <?php } elseif ( $sidebar === 'leftSidebar' ) { ?>

      <div class="col-md-4 col-lg-4 col-xl-4 col-sm-12">
        <?php get_sidebar(); ?>
      </div>

      <div class="col-md-8 col-lg-8 col-xl-8 col-sm-12 pl-5">

        <?php
				while ( have_posts() ) :
					the_post();
					get_template_part( 'template-parts/content', get_post_type() );
					milors_author_bio();
					milors_related_post(array(
							'taxonomy' => 'post_tag',
							'limit' => 3
						));
					
					// If comments are open or we have at least one comment, load up the comment template.
					if ( comments_open() || get_comments_number() ) :
						comments_template();
					endif;

				endwhile; // End of the loop.
				?>

      </div>

      <?php } else { // No Sidebar?>

      <div class="col-12 col-md-12 col-sm-12 no-sidebar">

        <?php
				while ( have_posts() ) :
					the_post();

					get_template_part( 'template-parts/content', get_post_type() );
				?>

        <div class="no-sidebar single-post">
          <?php

						milors_author_bio();

						milors_related_post(array(
							'taxonomy' => 'category',
							'limit' => 6
						)); 

					// If comments are open or we have at least one comment, load up the comment template.
					if ( comments_open() || get_comments_number() ) :
						comments_template();
					endif;

					?>
        </div>

        <?php endwhile; // End of the loop.
					?>

      </div>

      <?php } ?>

    </div>

  </div><!-- #primary -->

  <?php get_footer(); ?>