Using Advanced Custom Fields for a wordpress site I create a custom field for Users and its type is “User”, it is also set to support multiple selection. The idea is to link users to each other as friends.
To update the field I used update_field() but it me took time to figure out how to make it work.
At first I tried to push the new user id to the field :
<?php
// ADDING friend
$user_id = 'user_1'; // user id = 1
$new_friend_id = 2;
// retrieve current friends
$friends = get_field('friends', $user_id);
$friends[] = $new_friend_id;
// update field
update_field('friends', $friends, $user_id);
?>
But unfortunately this doesn’t work, for more than one user you should expect the wrong user to be added, the same for removing friend :
<?php
// REMOVING friend
$user_id = 'user_1'; // user id = 1
$friend_id_to_remove = 2;
// remove friend
foreach ($friends as $key => $friend) {
if($friend['ID'] != $friend_id_to_remove) {
unset($friends[$key]);
// or array_splice($friends, $key, 1);
break;
}
}
// update field
update_field('friends', $friends, $user_id);
?>
To make it work you have to create a new array and populate it with same type of datas :
<?php
// ADDING friend
$user_id = 'user_1'; // user id = 1
$new_friend_id = 2;
$newfriends = array();
// retrieve current friends
$friends = get_field('friends', $user_id);
foreach ($friends as $key => $friend) {
array_push($newfriends, $friend['ID']);
}
// add new user
array_push($newfriends, $new_friend_id);
// update field
update_field('friends', $newfriends, $user_id);
?>
And the same to remove a friend :
<?php
// REMOVING friend
$user_id = 'user_1'; // user id = 1
$friend_id_to_remove = 2;
$newfriends = array();
// retrieve current friends
$friends = get_field('friends', $user_id);
foreach ($friends as $key => $friend) {
if($friend['ID'] != $friend_id_to_remove) {
array_push($newfriends, $friend['ID']);
}
}
// update field
update_field('friends', $newfriends, $user_id);
?>
You can notice that the value of the custom field is an array of object and the one we create is only an array of ids.