TEC > Add event description with markup to the iCal export feed.

ical-description-with-markup.php

<?php
/* 
 * Description:  Add event description with markup to the  iCal export feed.
 * Usage:        Paste the below snippet into your active (child) theme's functions.php file
 *
 * Plugin:       The Events Calendar
 * Author:       Andras Guseo
 * Last updated: 2021-04-13
 */

add_filter( 'tribe_ical_feed_item', 'tec_add_html_description_to_ical', 10, 2 );

function tec_add_html_description_to_ical( $item, $event_post ) {
	$content = $event_post->post_content;
	$pattern = '/(<!--).*(-->)/i';
	$content = preg_replace( $pattern, '', $content );
	$item['X-ALT-DESC'] = 'X-ALT-DESC:' . tec_replace( trim( str_replace( '</p>', '</p> ', $content ) ) );
    
	return $item;
}

function tec_replace( $text = '', $search = [], $replacement = [] ) {
	$search = empty( $search ) ? [ ',', "\n", "\r" ] : $search;
	$replacement = empty( $replacement ) ? [ '\,', '\n', '' ] : $replacement;

	return str_replace( $search, $replacement, html_entity_decode( $text, ENT_QUOTES ) );
}