title: External url for featured image on woocommerce single product page via plug-in
body: <p>I am using a external url link plugin (<a href="http://epicplugins.com/external-url-link-to-featured-images/" rel="nofollow">http://epicplugins.com/external-url-link-to-featured-images/</a>)  to set the featured image on a product. 
  The image is showing for the thumbnails but not in the single product image page. On the singleproductimage.php page I'm not sure if I edit:</p>
  
  <pre><code>$image = get_the_post_thumbnail( $post-&gt;ID, apply_filters( 'single_product_large_thumbnail_size', 'shop_single' )
  </code></pre>
  
  <p>or</p>
  
  <pre><code>echo apply_filters( 'woocommerce_single_product_image_html', sprintf( '&lt;a href="%s" itemprop="image" class="woocommerce-main-image zoom" title="%s" data-rel="prettyPhoto' . $gallery . '"&gt;%s&lt;/a&gt;', $image_link, $image_title, $image ), $post-&gt;ID );
  
          } else {
  
          echo apply_filters( 'woocommerce_single_product_image_html', sprintf( '&lt;img src="%s" alt="Placeholder" /&gt;', wc_placeholder_img_src() ), $post-&gt;ID );
  
      }
  </code></pre>
  
  <p>and if to add a hook or a variable. I'm trying to figure out what function is causing it to work for the thumbnail:</p>
  
  <pre><code>&lt;?php
  /**
   * Single Product Thumbnails
   *
   * @author      WooThemes
   * @package     WooCommerce/Templates
   * @version     2.0.3
   */
  
  if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly
  
  global $post, $product, $woocommerce;
  
  $attachment_ids = $product-&gt;get_gallery_attachment_ids();
  
  if ( $attachment_ids ) {
      ?&gt;
      &lt;div class="thumbnails"&gt;&lt;?php
  
          $loop = 0;
          $columns = apply_filters( 'woocommerce_product_thumbnails_columns', 3 );
  
          foreach ( $attachment_ids as $attachment_id ) {
  
              $classes = array( 'zoom' );
  
              if ( $loop == 0 || $loop % $columns == 0 )
                  $classes[] = 'first';
  
              if ( ( $loop + 1 ) % $columns == 0 )
                  $classes[] = 'last';
  
              $image_link = wp_get_attachment_url( $attachment_id );
  
              if ( ! $image_link )
                  continue;
  
              $image       = wp_get_attachment_image( $attachment_id, apply_filters( 'single_product_small_thumbnail_size', 'shop_thumbnail' ) );
              $image_class = esc_attr( implode( ' ', $classes ) );
              $image_title = esc_attr( get_the_title( $attachment_id ) );
  
              echo apply_filters( 'woocommerce_single_product_image_thumbnail_html', sprintf( '&lt;a href="%s" class="%s" title="%s" data-rel="prettyPhoto[product-gallery]"&gt;%s&lt;/a&gt;', $image_link, $image_class, $image_title, $image ), $attachment_id, $post-&gt;ID, $image_class );
  
              $loop++;
          }
  
      ?&gt;&lt;/div&gt;
      &lt;?php
  }
  </code></pre>
  
  <p>and implement that into the single product page:</p>
  
  <pre><code>&lt;?php
  /**
   * Single Product Image
   *
   * @author      WooThemes
   * @package     WooCommerce/Templates
   * @version     2.0.14
   */
  
  if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly
  
  global $post, $woocommerce, $product;
  
  ?&gt;
  &lt;div class="images"&gt;
  
      &lt;?php
          if ( has_post_thumbnail() ) {
  
              $image_title        = esc_attr( get_the_title( get_post_thumbnail_id() ) );
              $image_link         = wp_get_attachment_url( get_post_thumbnail_id() );
              $image              = get_the_post_thumbnail( $post-&gt;ID, apply_filters( 'single_product_large_thumbnail_size', 'shop_single' ), array(
                  'title' =&gt; $image_title
                  ) );
              $attachment_count   = count( $product-&gt;get_gallery_attachment_ids() );
  
              if ( $attachment_count &gt; 0 ) {
                  $gallery = '[product-gallery]';
              } else {
                  $gallery = '';
              }
  
              echo apply_filters( 'woocommerce_single_product_image_html', sprintf( '&lt;a href="%s" itemprop="image" class="woocommerce-main-image zoom" title="%s" data-rel="prettyPhoto' . $gallery . '"&gt;%s&lt;/a&gt;', $image_link, $image_title, $image ), $post-&gt;ID );
  
          } else {
  
              echo apply_filters( 'woocommerce_single_product_image_html', sprintf( '&lt;img src="%s" alt="Placeholder" /&gt;', wc_placeholder_img_src() ), $post-&gt;ID );
  
          }
      ?&gt;
  
      &lt;?php do_action( 'woocommerce_product_thumbnails' ); ?&gt;
  
  &lt;/div&gt;
  </code></pre>
  
  <p>, but as you can see, I don't know what I'm doing.</p>