Add div section within the_content() as a short code

snippet.php

<?php
/*
 * Add div section within the content as a short code.
 *
 * This allows users to edit content in visual mode without stripping
 * out necessary but hidden <div> tags.
 *
 * Example usages:
 * [section]My Content[/section] = <div>My Content</div>
 * [section width='6']My Content[/section] = <div class="col6">My Content</div>
 * [section width='6' class='last']My Content[/section] = <div class="col6 last">My Content</div>
 * [section class='my-class']My Content[/section] = <div class="my-class">My Content</div>
 */
function create_section($atts,$content){
  extract(shortcode_atts(array(
		'width' => '',
		'class' => ''
	), $atts));
	if($width || $class){
		$classes = ' class="';
		$classes .= ($width ? 'col'.$width : '');
		$classes .= ($width && $class ? ' ' : '');
		$classes .= $class.'" ';
	}
	$return_string = '<div'.$classes.'>'.do_shortcode($content).'</div>';
	return $return_string;
}
add_shortcode('section', 'create_section');