function to return comma separated list of meta values

Question

I'm customizing the admin edit.php screen and I have a column that displays a meta key $gear. But it only lists the first value instead of returning a list of all the values. Here's the bit that matters:

add_action( 'manage_artists_posts_custom_column', 'manage_artists_columns', 10, 2 );
function manage_artists_columns( $column, $post_id ) {
    global $post;
    switch( $column ) {
        case 'gear' :
        $gear = get_post_meta( $post_id, 'gear', true ); 
            if ( empty( $gear ) )
                echo __( '' );
            else
                printf( __( '%s' ), $gear );

            break;

        default :
            break;
    }
}

I use a similar get_post_meta() call on the front end that uses

if( $gear = get_post_meta($post->ID, 'gear') 
echo implode( $gear, ', ' );

but I couldn't get it to adapt to this application. How do i get printf to output all values?

Answer 1

$gear = get_post_meta( $post_id, 'gear', true );

… will return the last value only, because you told it do that with the last parameter. Drop it, and you will get an array of all values:

$gear = get_post_meta( $post_id, 'gear' );

Then print it with:

print join( $gear, ', ' );

And as Chip has pointed out: Do not use the translation function for values that are not translatable. And even translatable values need a text domain.