wp-includes/formatting.php:3967Generates an excerpt from the content, if needed.
$textstringoptional''$postWP_Post|object|intoptionalnullstring4 hooks fire while wp_trim_excerpt() runs, in this order:
Filters the maximum number of words in a post excerpt.
Filters the string in the "more" link displayed after a trimmed excerpt.
Filters the trimmed excerpt string.
function wp_trim_excerpt( $text = '', $post = null ) { $raw_excerpt = $text; if ( '' === trim( $text ) ) { $post = get_post( $post ); $text = get_the_content( '', false, $post ); $text = strip_shortcodes( $text ); $text = excerpt_remove_blocks( $text ); $text = excerpt_remove_footnotes( $text ); /* * Temporarily unhook wp_filter_content_tags() since any tags * within the excerpt are stripped out. Modifying the tags here * is wasteful and can lead to bugs in the image counting logic. */ $filter_image_removed = remove_filter( 'the_content', 'wp_filter_content_tags', 12 ); /* * Temporarily unhook do_blocks() since excerpt_remove_blocks( $text ) * handles block rendering needed for excerpt. */ $filter_block_removed = remove_filter( 'the_content', 'do_blocks', 9 ); /** This filter is documented in wp-includes/post-template.php */ $text = apply_filters( 'the_content', $text ); $text = str_replace( ']]>', ']]>', $text ); // Restore the original filter if removed. if ( $filter_block_removed ) { add_filter( 'the_content', 'do_blocks', 9 ); } /* * Only restore the filter callback if it was removed above. The logic * to unhook and restore only applies on the default priority of 10, * which is generally used for the filter callback in WordPress core. */ if ( $filter_image_removed ) { add_filter( 'the_content', 'wp_filter_content_tags', 12 ); } /* translators: Maximum number of words used in a post excerpt. */ $excerpt_length = (int) _x( '55', 'excerpt_length' ); /** * Filters the maximum number of words in a post excerpt. * * @since 2.7.0 * * @param int $number The maximum number of words. Default 55. */ $excerpt_length = (int) apply_filters( 'excerpt_length', $excerpt_length ); /** * Filters the string in the "more" link displayed after a trimmed excerpt. * * @since 2.9.0 * * @param string $more_string The string shown within the more link. */ $excerpt_more = apply_filters( 'excerpt_more', ' ' . '[…]' ); $text = wp_trim_words( $text, $excerpt_length, $excerpt_more ); } /** * Filters the trimmed excerpt string. * * @since 2.8.0 * * @param string $text The trimmed text. * @param string $raw_excerpt The text prior to trimming. */ return apply_filters( 'wp_trim_excerpt', $text, $raw_excerpt );}Introduced in 1.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/formatting.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.