Remove empty terms from array, sort alphabetically, update back to repeating field

Question

I have a repeating field that stores text terms in an array, like this:

[0] => 
[1] => NUC Lights
[2] => Smoke Alarm
[3] => Binoculars

You'll note key A has no value, and they're not ordered alphabetically. What I want to do is to take the array above, remove empty values, sort it, and resave it like below:

[0] => Binoculars
[1] => NUC Lights
[2] => Smoke Alarm

Here's my current code:

// Post Types to include
$post_args = array(
    'posts_per_page' => -1,
    'post_type' => array(
        'boat'
    ),
);

// The Query
$post_query = new WP_Query( $post_args );
$posts = $post_query->posts;

foreach($posts as $post) {

    $boat_safety_terms = get_post_meta( $post->ID, 'wpcf-all-safety-terms', false );
    $boat_safety_terms_cleaned = array_filter( $boat_safety_terms );
    $boat_safety_terms_cleaned_sorted = sort( $boat_safety_terms_cleaned );

    error_log( print_r( $boat_safety_terms_cleaned_sorted, TRUE ) );

}

But my log only shows 1 for each boat for some reason. Any idea what might be going wrong with it?

Also, I'm assuming I'll want to use update_post_meta to save the array back to the field?

Answer 1

$boat_safety_terms_cleaned_sorted = sort( $boat_safety_terms_cleaned );
error_log( print_r( $boat_safety_terms_cleaned_sorted, TRUE ) );

PHP's sort accepts an array reference and sorts in-place, and returns success or failure - hence the 1 you're getting. You want:

sort( $boat_safety_terms_cleaned );
error_log( print_r( $boat_safety_terms_cleaned, TRUE ) );

Also, I'm assuming I'll want to use update_post_meta to save the array back to the field?

Yes, that would work fine. I assume this is utility method that you'll manually trigger once per post though, and not something that gets run as a matter of course? If it's on save of a boat then there are probably better ways to filter the value as you save it, depending on how you're doing that.