<?php // If a featured image is set, insert into layout and use Interchange // to select the optimal image size per named media query. if ( has_post_thumbnail( $post->ID ) ) : ?> <header class="featured-hero" role="banner" data-interchange="[<?php the_post_thumbnail_url( 'featured-small' ); ?>, small], [<?php the_post_thumbnail_url( 'featured-medium' ); ?>, medium], [<?php the_post_thumbnail_url( 'featured-large' ); ?>, large], [<?php the_post_thumbnail_url( 'featured-xlarge' ); ?>, xlarge]"> </header> <?php endif;