page.php

<?php
/**
 * The template for displaying all pages.
 *
 * This is the template that displays all pages by default.
 * Please note that this is the WordPress construct of pages
 * and that other 'pages' on your WordPress site will use a
 * different template.
 *
 * @package cornerstone
 */

get_header(); ?>
	<?php 
		// sidebar custom field check. 
		$sidebar = get_post_meta( get_the_ID(), 'uc_sidebar', true );
		if( !is_active_sidebar( $sidebar ) ){
			foreach(get_post_ancestors(get_the_ID()) as $ancestor){
				$parent_sidebar = get_post_meta( $ancestor, 'uc_sidebar', true );
				$parent_sidebar_children = get_post_meta( $ancestor, 'uc_sidebar_children', true );
				if( is_active_sidebar( $parent_sidebar ) && $parent_sidebar_children != '' && $parent_sidebar_children ){
					$sidebar = $parent_sidebar;
					break;
				}
			}
		}
	?>
	<div class="row">
		<div class="col-md-<?php echo (is_active_sidebar( $sidebar )?9:12); ?>">
			<div id="primary" class="content-area">
				<main id="main" class="site-main" role="main">
					
					<?php while ( have_posts() ) : the_post(); ?>

						<?php get_template_part( 'content', 'page' ); ?>

						<?php
							// If comments are open or we have at least one comment, load up the comment template
							if ( comments_open() || '0' != get_comments_number() ) :
								comments_template();
							endif;
						?>

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

				</main><!-- #main -->
			</div><!-- #primary -->
		</div>
		<?php
			if ( is_active_sidebar( $sidebar ) ) { 
				echo '<div class="col-sm-3">';
				dynamic_sidebar( $sidebar );
				echo '</div>';
			} 
		?>
	</div><!-- /row -->
<?php get_footer(); ?>