Allow users to change their vote

This isn’t really a support post but I though I would relay the info in case you either want to develop this further, or if you have suggestions on a better way to implement this.

I have a small site that is members only. Members need to be able to change their vote easily.

In order to do this, I added the below code right before the following line in yop_poll_model.php:

if ( $this->user_have_votes_to_vote( $voter ) ){

Custom code:

if ( 'wordpress' == $voter['user_type'] ) {
	global $wpdb;
	$wpdb->query( $wpdb->prepare( "
			update " . $wpdb->yop_polls . " p
			set total_votes = total_votes - (
				select count(pv.poll_id)
				from " . $wpdb->yop_poll_voters . " pv
				where p.id = pv.poll_id and pv.user_id = %d and pv.user_type = 'wordpress'
				),
			total_answers = total_answers - (
				select count(pl.answer_id)
				from wp_2_yop_poll_logs pl
				where p.id = pl.poll_id and pl.user_id = %d and pl.user_type = 'wordpress'
				)
			where p.id = %d;
			", $current_user->ID, $current_user->ID, $poll_id ) );
	$wpdb->query( $wpdb->prepare( "
			update " . $wpdb->yop_poll_answers . " pa
			set votes = votes - (
				select count(pl.answer_id)
				from " . $wpdb->yop_poll_logs . " pl
				where pa.id = pl.answer_id and pa.poll_id = pl.poll_id and pl.user_id = %d and pl.user_type = 'wordpress'
				)
			where pa.poll_id = %d;
			", $current_user->ID, $poll_id ) );
	$wpdb->query( $wpdb->prepare( "
			delete from " . $wpdb->yop_poll_voters . "
			where poll_id = %d and
			user_id = %d and
			user_type = 'wordpress';
			", $poll_id, $current_user->ID ) );
	$wpdb->query( $wpdb->prepare( "
			delete from " . $wpdb->yop_poll_logs . "
			where poll_id = %d and
			user_id = %d and
			user_type = 'wordpress';
			", $poll_id, $current_user->ID ) );
}

https://wordpress.org/plugins/yop-poll/