Show all wp_get_post_terms slugs

Question

I am using the following code to display my custom taxonomy slugs. However it is only displaying the first category and not all the related categories. I know this is fairly simple and is to do with [0] but I can't figure out how to change it.

$getslugid = wp_get_post_terms( $post->ID, 'opd_taggallery' ); 
$getslug = $getslugid [0]->slug;
echo $getslug;

Answer 1

This is more of a PHP question, but the solution is simple - you need to use a foreach-loop on $getslug, because you just echo the slug of the first taxonomy.

The function wp_get_post_terms() does not return a single object, but an array of objects. You are right with the [0], this indicates that you are checking the first entry of said array.

Your function should look something like this:

$getslugid = wp_get_post_terms( $post->ID, 'opd_taggallery' ); 
foreach( $getslugid as $thisslug ) {

    echo $thisslug->slug . ' '; // Added a space between the slugs with . ' '

}

Answer 2

The WordPres Core function wp_list_pluck() should make this fairly easy.

$getslugid = wp_get_post_terms( $post->ID, 'opd_taggallery' ); 
$slugs = implode(', ',wp_list_pluck($getslugid,'slug'));
echo $slugs;

Answer 3

In newer WordPress versions it is possible to directly query only the taxonomy slugs. I think this came with the introduction of the WP_Term_Query class in WP version 4.6.0.

$slugs = wp_get_post_terms( $post->ID, 'opd_taggallery', array( 
    'fields' => 'id=>slug',
) );
echo implode( " ", $slugs );