Shoestrap 3 - display featured image of single posts into the extra header area

functions.php

<?php

/*
* Display featured images in extra header area of individual posts
*/

function my_featured_image() {
  global $ss_framework, $ss_settings;
  $data = array();

  if ( ! has_post_thumbnail() || '' == get_the_post_thumbnail() ) {
    return;
  }

  // only in single posts
  if ( is_single() ) {
    
    $data['url'] = wp_get_attachment_url( get_post_thumbnail_id() );

    // $data['width']  = Shoestrap_Layout::content_width_px();
    $data['width']  = '1920';

    $data['height'] = '350';
        
  }

  $image = Shoestrap_Image::image_resize( $data );

  echo $ss_framework->clearfix() . '<a href="' . get_permalink() . '"><img class="featured-image ' . $ss_framework->float_class('left') . '" src="' . $image['url'] . '" /></a>';
}
add_action( 'shoestrap_pre_wrap', 'my_featured_image' );