bbp_get_form_topic_tags()

	function bbp_get_form_topic_tags() {

		// Get _POST data
		if ( bbp_is_post_request() && isset( $_POST['bbp_topic_tags'] ) ) {
			$topic_tags = $_POST['bbp_topic_tags'];

		// Get edit data
		} elseif ( bbp_is_single_topic() || bbp_is_single_reply() || bbp_is_topic_edit() || bbp_is_reply_edit() ) {

			// Determine the topic id based on the post type
			switch ( get_post_type() ) {

				// Post is a topic
				case bbp_get_topic_post_type() :
					$topic_id = get_the_ID();
					break;

				// Post is a reply
				case bbp_get_reply_post_type() :
					$topic_id = bbp_get_reply_topic_id( get_the_ID() );
					break;
			}

			$new_terms = array();

			// Topic exists
			if ( !empty( $topic_id ) ) {

				// Topic is spammed so display pre-spam terms
				if ( bbp_is_topic_spam( $topic_id ) ) {
					$new_terms = get_post_meta( $topic_id, '_bbp_spam_topic_tags', true );

				// Topic is not spam so get real terms
				} else {
					$terms     = array_filter( (array) get_the_terms( $topic_id, bbp_get_topic_tag_tax_id() ) );
					$new_terms = wp_list_pluck( $terms, 'name' );
				}
			}

			// Set the return value
			$topic_tags = ( !empty( $new_terms ) ) ? implode( ', ', $new_terms ) : '';

		// No data
		} else {
			$topic_tags = '';
		}

		return apply_filters( 'bbp_get_form_topic_tags', esc_attr( $topic_tags ) );
	}