RSS output hacks – exclude categories, add spacing

Some fun hacks Walter (WPAllied) did for an investing site I built.

I was building a stock investing site…that was auto-picked up by Zapier’s RSS tool, which pushed to Buffer’s auto-posting schedule, which then pushed to Twitter.

My goal was to show the following on Twitter in exactly this manner:

• Post title
• Post url
• And stock symbols (e.g. $ABC, $DEF, $GHI) which I set as “tags”.

Title of my stock post https://mysite.com/posturl $ABC $DEF $GHI

But the problem was the default WordPress RSS output showed all categories and tags, and also in a format I didn’t want.

• It showed the categories. (Again, I didn’t want to show this.)
• It put commas between each category/tag. (Wasting space.)
• There was no space before the tags, making them unclickable in Twitter.

Title of my stock post https://mysite.com/posturl CAT1,CAT2,TAG1,TAG2

Walter’s code fix below:

• Declare a namespace to avoid code conflict.
• Output RSS category element to show categories without commas and with a space between each one.
• Disable categories from showing in feed output. (Now shows only tags.)
• Put this snippet in your theme functions.php file.

/**
 * Add <yoursite> namespace to RSS2.
 */
add_action( 'rss2_ns', function() {
	echo 'xmlns:yoursite="http://yoursite.com/ns/yoursite#"';
});

/**
 * Show post categories/tags in feeds with a single string space separated, and no comma.
 * 
 * Disable Categories from showing in feed output.
 */
add_action('rss2_item', function() {
//	$categories = get_the_category();
	$tags       = get_the_tags();
	$the_list   = '';
	$cat_names  = array();

//	if ( ! empty( $categories ) ) {
//		foreach ( (array) $categories as $category ) {
//			$cat_names[] = sanitize_term_field( 'name', $category->name, $category->term_id, 'category', 'rss' );
//		}
//	}

	if ( ! empty( $tags ) ) {
		foreach ( (array) $tags as $tag ) {
			$cat_names[] = sanitize_term_field( 'name', $tag->name, $tag->term_id, 'post_tag', 'rss' );
		}
	}

	$cat_names = array_unique( $cat_names );
	$cat_name  = implode( ' ', $cat_names );

	$the_list .= "\t\t<yoursite:categories><![CDATA[" . html_entity_decode( $cat_name, ENT_COMPAT, get_option( 'blog_charset' ) ) . "]]></yoursite:categories>\n";

	echo $the_list;

I hope you enjoyed! It was a fun little hack and did the job perfectly for what we wanted!