Inserting shortcode is blanking excerpt - any ideas?

Question

I wrapped a shortcode around my post content and I have noticed it is making the excerpt blank on archive pages instead of auto generating one from the_content/post. At a loss as to what is causing it or what to try. Its not even outputting the shortcode in the_excerpt its just blank. I would have thought if there was going to be a problem it would have been the shortcode appearing as part of the_excerpt but its just blank full stop. All my predefined shortcode does is wrap some complex HTML5 tags around the content which an author would make mistakes doing on a regular basis for consistency in certain situations so its not a complex shortcode. My post is outputting perfectly with the_content. As soon as I remove the shortcode it works again. If I put the shortcodes back in and set a manual excerpt it works so its only when it has to auto generate the_excerpt from a post wrapped in this shortcode. Appreciate any ideas if anyone else has experienced something similar as I am at a loss to explain it or how to resolve.

Many thanks.

In simple/stripped back terms im wrapping for example this:

add_shortcode( 'ARTICLE_SECTION', 'trg_shortcode_article_section');
function trg_shortcode_article_section_run( $content ) {
  global $shortcode_tags;

  // Backup current registered shortcodes and clear them all out
  $orig_shortcode_tags = $shortcode_tags;
  remove_all_shortcodes();

  add_shortcode( 'ARTICLE_SECTION', 'trg_shortcode_article_section' );

  // Do the shortcode (only the one above is registered)
  $content = do_shortcode( $content );

  // Put the original shortcodes back
  $shortcode_tags = $orig_shortcode_tags;

  return $content;
}
// actual shortcode function
function trg_shortcode_article_section( $atts, $content = null ) {

    $atts = array();

    $output = '<section>';
    $output .= $content . '</section>';
    return $output;
}
add_filter( 'the_content', 'trg_shortcode_article_section_run', 7 );

In partial loop:

<p><?=trg_excerpt_article()?></p>

Ive put in to debug early right at start before anything else just:

function trg_excerpt_article(){
  echo '<!-- excerpt - ' . get_the_excerpt() . ' -->';
}

That returns blank as well.

Answer 1

Excerpts remove all mark-up and shortcodes. Try adding the following into your functions.php:

add_filter('the_excerpt', 'do_shortcode');

This should enable shortcodes in your excerpt again. Bear in mind the generated HTML5 will be stripped out.

Answer 2

I have managed to fix the issue. Wordpress strip_shortcodes() wasnt cutting it.

It seems to me that Wordpress doesnt like a whole post to be wrapped in shortcodes and returns the excerpt blank. It also could be the altered timings that I have applied my shortcodes to the_content. However I believe it is the former having read also some others online experiencing this. For the excerpts I have stripped the shortcodes manually when detecting empty excerpts.

function my_custom_excerpt($length_callback='', $more_callback='') {

        if(function_exists($more_callback)){
            add_filter('excerpt_more', $more_callback);
        }

        if(function_exists($length_callback)){
            add_filter('excerpt_length', $length_callback);
        }

        $output = get_the_excerpt();

        if( empty( $output ) ){ 
            $excerpt = get_the_content();
            $excerpt = preg_replace('/\[(.*)\]/','',$excerpt);
            $excerpt = esc_attr( strip_tags( stripslashes( $excerpt ) ) );
            $excerpt = wp_trim_words( $excerpt, ( (function_exists($length_callback)) ? call_user_func($length_callback,55) : 55 ), ( (function_exists($more_callback)) ? call_user_func($more_callback) : '' ) );

            $output = $excerpt;
        }

        $output = apply_filters('wptexturize', $output);
        $output = apply_filters('convert_chars', $output);
        return $output;
}

Not sure yet if this is 100% fool proof but it seems to handle when a post is wrapped in shortcodes being returned empty and then proceeds to get the_content itself strips any shortcodes out and formats the excerpt as it should from there. Hopefully this helps others out who experience similar issues.

Thanks for the help and advice.

Answer 3

If you want the excerpt to run the same filters as the posts have, you can add this to your functions.php.

add_filter( 'get_the_excerpt', 'get_the_content', 5 );

Keep in mind, that your shortcode might be considered one word when it comes to any setting that limits the excerpt to a certain number of words. Thus, if your shortcode prints out 10 words, and your setting is set to 12 words, is't actually going to print out 21 words (9 of the original words and the 12 words your shortcode prints out).