The following code gets the "organisation" taxonomy terms associated with the last 20 "article" or "viewpoint" posts.

First, it gets the posts, $recent_posts. Second, it pushes each of those "organisation" terms on to a new array, $recent_companies.

Later, I deduplicate them and display those terms. It all works fine.

The only thing is, with debugging enabled, I can see that the line foreach ($orgs_in_post as $org_single) { throws the following PHP warning:

Warning: Invalid argument supplied for foreach()

It doesn't stop the code working. I've only just discovered the warning.But I'd like to eliminate it. So what is going on with this code?

          <?php
          // Get latest posts
          $args = array(
            'numberposts' => 20,
            'offset' => 0,
            'category' => 0,
            'orderby' => 'post_date',
            'order' => 'DESC',
            'include' => '',
            'exclude' => '',
            'meta_key' => '',
            'meta_value' =>'',
            'post_type' => array('article','viewpoint'),
            'post_status' => 'publish',
            'suppress_filters' => true
          );
          $recent_posts = wp_get_recent_posts( $args, ARRAY_A );

                $recent_companies = array();
          // Get companies in latest posts
          foreach ($recent_posts as $post) {
            // get terms
            $orgs_in_post = get_the_terms($post['ID'], 'company');
            foreach ($orgs_in_post as $org_single) {
              array_push($recent_companies, $org_single->term_id);
            }
          }

The following code gets the "organisation" taxonomy terms associated with the last 20 "article" or "viewpoint" posts.

First, it gets the posts, $recent_posts. Second, it pushes each of those "organisation" terms on to a new array, $recent_companies.

Later, I deduplicate them and display those terms. It all works fine.

The only thing is, with debugging enabled, I can see that the line foreach ($orgs_in_post as $org_single) { throws the following PHP warning:

Warning: Invalid argument supplied for foreach()

It doesn't stop the code working. I've only just discovered the warning.But I'd like to eliminate it. So what is going on with this code?

          <?php
          // Get latest posts
          $args = array(
            'numberposts' => 20,
            'offset' => 0,
            'category' => 0,
            'orderby' => 'post_date',
            'order' => 'DESC',
            'include' => '',
            'exclude' => '',
            'meta_key' => '',
            'meta_value' =>'',
            'post_type' => array('article','viewpoint'),
            'post_status' => 'publish',
            'suppress_filters' => true
          );
          $recent_posts = wp_get_recent_posts( $args, ARRAY_A );

                $recent_companies = array();
          // Get companies in latest posts
          foreach ($recent_posts as $post) {
            // get terms
            $orgs_in_post = get_the_terms($post['ID'], 'company');
            foreach ($orgs_in_post as $org_single) {
              array_push($recent_companies, $org_single->term_id);
            }
          }

• taxonomy
• terms

1 Answer 1

According to the documentation, get_the_terms() returns an array of WP_Term objects, or a boolean false value, or a WP_Error object. The last two won't work with foreach().

You could update your code to check for these conditions:

$orgs_in_post = get_the_terms($post['ID'], 'company');
if ( is_array( $orgs_in_post ) ) {
    foreach ($orgs_in_post as $org_single) {
        array_push($recent_companies, $org_single->term_id);
    }
}