Custom WP excerpts (with allowed HTML tags and custom read more link)

functions.php

<?php
/**
 * Customize excerpt length and style.
 *
 * @param  string The raw post content.
 * @return string
 */
function red_wp_trim_excerpt( $text ) {
	$raw_excerpt = $text;
	
	if ( '' == $text ) {
		// retrieve the post content
		$text = get_the_content('');
		
		// delete all shortcode tags from the content
		$text = strip_shortcodes( $text );
		
		$text = apply_filters( 'the_content', $text );
		$text = str_replace( ']]>', ']]&gt;', $text );
		
		// indicate allowable tags
		$allowed_tags = '<p>,<a>,<em>,<strong>,<blockquote>,<cite>';
		$text = strip_tags( $text, $allowed_tags );
		
		// change to desired word count
		$excerpt_word_count = 50;
		$excerpt_length = apply_filters( 'excerpt_length', $excerpt_word_count );
		
		// create a custom "more" link
		$excerpt_end = '<span>[...]</span><p><a href="' . get_permalink() . '" class="read-more">Read more &rarr;</a></p>'; // modify excerpt ending
		$excerpt_more = apply_filters( 'excerpt_more', ' ' . $excerpt_end );
		
		// add the elipsis and link to the end if the word count is longer than the excerpt
		$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 );
}

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