Come posso ottenere solo i termini genitore?

Sì,passa semplicementeilparametrogenitore a get_terms quando lo chiami,come ha sottolineato Michael.

Dalmomento che WP 4.5 questo è l'uso consigliato:

 $myterms = get_terms( array( 'taxonomy' => 'taxonomy_name', 'parent' => 0 ) );
 

Prima di WP 4.5 questoera l'utilizzopredefinito:

 $myterms = get_terms( 'taxonomy_name_here', array( 'parent' => 0 ) );
 

Restituiràtuttii termini che hanno un valoreprincipale di 0,ades.termini diprimo livello.

Yes, just pass in the parent parameter to get_terms when you call it, as Michael pointed out.

Since WP 4.5 this is the recommend usage:

$myterms = get_terms( array( 'taxonomy' => 'taxonomy_name', 'parent' => 0 ) );

Prior to WP 4.5 this was the default usage:

$myterms = get_terms( 'taxonomy_name_here', array( 'parent' => 0 ) );

Will return all terms that have a parent value of 0, ie. top level terms.

utilizzailparametro "genitore":

http://codex.wordpress.org/Function_Reference/get_terms

o

http://codex.wordpress.org/Function_Reference/get_categories

use the 'parent' parameter:

http://codex.wordpress.org/Function_Reference/get_terms

or

http://codex.wordpress.org/Function_Reference/get_categories

peri modelli diemail di woocommerce utilizza quanto segue:

 $terms = get_the_terms( $_product->id , 'product_cat');
    if($terms) {
        foreach( $terms as $term ) {
            $term = get_term_by("id", $term->parent, "product_cat");
            if ($term->parent > 0) {
                $term = get_term_by("id", $term->parent, "product_cat");
            }
            $cat_obj = get_term($term->term_id, 'product_cat');
            $cat_name = $cat_obj->name;
        }
    }
echo '<br />('. $cat_name . ')';
 

for woocommerce email templates use the following:

$terms = get_the_terms( $_product->id , 'product_cat');
    if($terms) {
        foreach( $terms as $term ) {
            $term = get_term_by("id", $term->parent, "product_cat");
            if ($term->parent > 0) {
                $term = get_term_by("id", $term->parent, "product_cat");
            }
            $cat_obj = get_term($term->term_id, 'product_cat');
            $cat_name = $cat_obj->name;
        }
    }
echo '<br />('. $cat_name . ')';

  $archive_cats= get_terms( 'archivecat', 'orderby=count&hide_empty=0&parent=0' );
 

 $archive_cats= get_terms( 'archivecat', 'orderby=count&hide_empty=0&parent=0' );