WordPress shortcode that adds classes to the html body

wp-shortcode-add-body-class.php

<?php // ...in functions.php
// adds wp shortcode that adds css classes to the html body
// use in your page and post content like this:
// [bodyclass class="add these classes to the body"]

function use_bodyclass_shortcode( $classes ) {
	
	global $post;
	
	// check if the post has the bodyclass shortcode
	if( isset($post->post_content) && has_shortcode( $post->post_content, 'bodyclass' ) ){

		// match the content of the first class="content" attribute in the bodyclass shortcode
		preg_match('/\[bodyclass(?:\s|\s[^\]]*\s)class=[\"\']([^\"\'\]]*)[\"\'][^\]]*\]/i', $post->post_content, $matches);
	
		// transform the matched string into an array of classes
		$addedClasses = explode(' ', $matches[1]);

		// add the new array to the wp body classes array
		$classes = array_merge($classes,$addedClasses);

	}
	return $classes;
	
}
add_filter( 'body_class', 'use_bodyclass_shortcode' );

// register the bodyclass function with WordPress will not return anything extra
function bodyclass_Func( $atts, $content = null ){ 
	return do_shortcode($content);
}
add_shortcode('bodyclass','bodyclass_Func');

?>