Excerpt allow HTML

functinos.php

<?php
// Show sharing buttons, e.g. from Jetpack
// http://tiptoppress.com/allow-html-in-excerpt-becomes-filteractions-code/
// TODO: Rewrite code as filter hook
// TODO: Multi select supported HTML elements in option (https://github.com/tiptoppress/category-posts-widget/issues/59)


function widget($args, $instance) {
  ...
  add_filter('the_excerpt', array($this,'allow_html_excerpt'));
  ...
  // do post loop
  // call the excerpt method
  the_excerpt();
  ...
  remove_filter('the_excerpt', array($this,'allow_html_excerpt'));
  ...
}

/**
 * Excerpt allow HTML
 */
function allow_html_excerpt($text) {
	global $post, $wp_filter;
	$new_excerpt_length = ( isset($this->instance["excerpt_length"]) && $this->instance["excerpt_length"] > 0 ) ? $this->instance["excerpt_length"] : 55;
	if ( '' == $text ) {
		$text = get_the_content('');
		$text = strip_shortcodes( $text );
		$text = apply_filters('the_content', $text);
		$text = str_replace('\]\]\>', ']]&gt;', $text);
		$text = preg_replace('@<script[^>]*?>.*?</script>@si', '', $text);
		$cphtml = array(
			'&lt;a&gt;',
			'&lt;br&gt;',
			'&lt;em&gt;',
			'&lt;i&gt;',
			'&lt;ul&gt;',
			'&lt;ol&gt;',
			'&lt;li&gt;',
			'&lt;p&gt;',
			'&lt;img&gt;',
			'&lt;script&gt;',
			'&lt;style&gt;',								
			'&lt;video&gt;',
			'&lt;audio&gt;'
		);
		$allowed_HTML = "";
		foreach ($cphtml as $index => $name) {
			if (in_array((string)($index),$this->instance['excerpt_allowed_elements'],true))
				$allowed_HTML .= $cphtml[$index];
		}			
		$text = strip_tags($text, htmlspecialchars_decode($allowed_HTML));
		$excerpt_length = $new_excerpt_length;		

		if( !empty($this->instance["excerpt_more_text"]) ) {
			$excerpt_more = $this->excerpt_more_filter($this->instance["excerpt_more_text"]); 
		}else if($filterName = key($wp_filter['excerpt_more'][10])) {
			$excerpt_more = $wp_filter['excerpt_more'][10][$filterName]['function'](0);
		}else {
			$excerpt_more = '[...]';
		}
		
		$words = explode(' ', $text, $excerpt_length + 1);
		if (count($words)> $excerpt_length) {
			array_pop($words);
			array_push($words, $excerpt_more);
			$text = implode(' ', $words);
		}
	}

	return '<p>' . $text . '</p>';
}