How to enable shortcodes in excerpts?

excerpts are generated from the content by a wordpress filter using the functions wp_trim_excerpt() located in /wp-includes/formatting.php (from line 1808) which uses the line $text = strip_shortcodes( $text );

if this would not be done, there would be a chance that the content generates something ugly – as in the case of the [gallery] shortcode for instance which then shows a bunch of styles 🙁

you might need to write your own filter function to replace wp_trim_excerpt() in which you could replace the above line of code with a line to include a ‘do_shortcode()’ part to execute the shortcode before shortening the content.

http://codex.wordpress.org/Plugin_API/Filter_Reference

this sounds more complicated that it is:

in functions.php of your theme, add a line to remove the existing filter, a second line to add your new filter, and the new function itself which you can more or less simply copy from the ‘wp_trim_excerpt()’ code:

remove_filter('get_the_excerpt', 'wp_trim_excerpt');
add_filter('get_the_excerpt', 'wp_trim_excerpt_do_shortcode');

function wp_trim_excerpt_do_shortcode($text) {
	$raw_excerpt = $text;
	if ( '' == $text ) {
		$text = get_the_content('');

		$text = do_shortcode( $text ); // CHANGED HERE

		$text = apply_filters('the_content', $text);
		$text = str_replace(']]>', ']]>', $text);
		$text = strip_tags($text);
		$excerpt_length = apply_filters('excerpt_length', 55);
		$excerpt_more = apply_filters('excerpt_more', ' ' . '[...]');
		$words = preg_split("/[\n\r\t ]+/", $text, $excerpt_length + 1, PREG_SPLIT_NO_EMPTY);
		if ( count($words) > $excerpt_length ) {
			array_pop($words);
			$text = implode(' ', $words);
			$text = $text . $excerpt_more;
		} else {
			$text = implode(' ', $words);
		}
	}
	return apply_filters('wp_trim_excerpt', $text, $raw_excerpt);
}

this is all.

hope it does what you expect 😉