jirsbek

<?php
/**
 * Add Param to Show Number of Posts in RSS
 *
 * Source: https://wordpress.stackexchange.com/questions/4736/get-all-posts-in-rss
 */
add_filter('option_posts_per_rss', 'my_posts_per_rss');
function my_posts_per_rss($option)
{
	if (isset($_GET['posts'])) {

jirsbek

<?php
/**
 * Add param to display gallery in full size in RSS
 */
add_filter(
	'shortcode_atts_gallery',
	function ($out) {
		$out['link'] = 'file'; // By defaul show file link in gallery, not attachmnet URL
		if (is_feed() and $_GET['gallery'] === 'full') {
			$out['size'] = 'full';

jirsbek

<?php
/**
 * Add RSS Feed Summary Params
 *
 * Source: https://wordpress.stackexchange.com/a/195197
 */
add_action('rss_tag_pre', function ($tag) {
	$summary = filter_input(INPUT_GET, 'summary', FILTER_SANITIZE_STRING);
	if ('yes' === $summary)
		add_filter('option_rss_use_excerpt', '__return_true');

jirsbek

<?php
/**
 * Add Image to RSS
 *
 * Source: https://wordpress.stackexchange.com/a/292763
 * Source: https://gist.github.com/DaveyJake/aa59667cd3ced5809b4d
 */
function remote_file_size($url)
{
	$data = get_headers($url, true);