WordPress | Tag cloud for categories via shortcode

tag-cloud-based-on-category-via-shortcode.php

<?php

function tag_cloud_shortcode($atts) {

	// first make sure we are within a category
	if (is_category()) {

		// get info of current category
		$category = get_category( get_query_var( 'cat' ) );
		// get current category ID
		$cat_id = $category->cat_ID;
		// loop through all posts within the current category ID
		$query_args = array( 'cat' => $cat_id, 'posts_per_page' => -1 );
		// create the new query
		$custom_query = new WP_Query( $query_args );

		// if this category has posts
		if ($custom_query->have_posts()) {

			while ($custom_query->have_posts()) : $custom_query->the_post();
				// grab the tags of each post in this query
				$posttags = get_the_tags();
				// if there are any tags that belong to posts in this query
				if ($posttags) {
					// for each one, grab that tag ID
					foreach($posttags as $tag) {
						$all_tags[] = $tag->term_id;
					}
				}
			endwhile;

		}

		// create list of each unique tag ID that as found
		$tags_arr = array_unique($all_tags);
		// pull the array apart to get each unique tag ID
		$tags_str = implode(",", $tags_arr);

		// display parameters for the output of the tags
		$args = array(
			'echo'      => false,
			'smallest'  => 12,
			'largest'   => 20,
			'unit'      => 'px',
			'number'    => 0,
			'format'    => 'list',
			'order'     => 'count',
			'include'   => $tags_str
		);

		// if the current category did have posts, then output the tag cloud and other information
		if ($custom_query->have_posts()) {
			return '<div class="fs-tag-wrapper"><h4 class="widgettitle">'. get_cat_name($cat_id) .' Tags</h4><div class="fs-tags">'. wp_tag_cloud($args) .'</div></div>';
		}
		// otherwise the current category didn't have any posts, so return nothing (otherwise it would try to return ALL tags of ANY category posts)
		else {
			return '';
		}

	}
}
add_shortcode( 'tagscloud', 'tag_cloud_shortcode' );