@hube2 I got somewhat further:
<?php
$motd = get_field('motd');
?>
<div id="<?php echo esc_attr($id); ?>" class="<?php echo esc_attr($className); ?>">
<?php
$molecule_month = get_the_terms($motd->ID , 'molecules_of_the_month' );
$month = array_pop($molecule_month);
$molecule_link = get_term_link( $month->term_id, 'molecules_of_the_month' );
// Set the post type here, and sort them randomly
// molecule of the month presented as random molecule of the day.
$args = array(
'post_type' => 'molecule',
'posts_per_page'=> 1,
'post_category' => 'molecule_of_the_month',
'order_by' => 'rand',
);
// Initiate a custom query
$cpt_query = new WP_Query($args);
// If the query has any post, start the loop
if($cpt_query->have_posts()){
while($cpt_query->have_posts()){
// Output a link and a thumbnail of the post
$cpt_query->the_post(); ?>
<div class="random-post">
<div class="motd-img">
<a href="<?php echo $molecule_link ?>">
<?php echo get_the_post_thumbnail( $motd->ID, 'full');?>"/>
</a>
</div>
<a href="<?php the_permalink();?>"><?php the_title();?></a>
</div><?php
}
} ?>
</div>
But got this error
: Uncaught TypeError: array_pop(): Argument #1 ($array) must be of type array, bool given in /Users/jasper/code/site/wp-content/themes/theme/blocks/random-molecule/block.php:30
Why would ID be null? It refers to $month = array_pop($molecule_month); and the field has been set before that line. And we do have molecules of the day(based on month) and molecules of the month.
