Ajax post filter by category

[Tartamata]

Hi everybody,
Im trying to make an ajax post filter by category.
So im following this tutorial: https://weichie.com/blog/wordpress-filter-posts-with-ajax/

So my problem is this hook:

add_action(‘wp_ajax_filter_projects’, ‘filter_projects’);
add_action(‘wp_ajax_nopriv_filter_projects’, ‘filter_projects’);

function filter_projects() {
$catSlug = $_POST[‘category’];

$ajaxposts = new WP_Query([
  'post_type' => 'post',
  'posts_per_page' => -1,
  'category_name' => $catSlug,
  'orderby' => 'menu_order', 
  'order' => 'desc',
]);
$response = '';

if($ajaxposts->have_posts()) {
  while($ajaxposts->have_posts()) : $ajaxposts->the_post();
    $response .= 'Results';
  endwhile;
} else {
  $response = 'empty';
}

echo $response;
exit;

}

When i put the following code in /functions.php it works, but when i move it to app/setup.php it doesn’t work.

Any idea?
is there any example on how to use ajax to call posts with Sage 10 ?

Thanks

[alwaysblank]

setup.php is namespaced, which means the functions in your callbacks also need to be namespaced—otherwise WordPress tries to call functions that don’t exist. The other app files (or maybe even setup) should have examples of how to do this.

[Tartamata]

Thank you @alwaysblank
I did this:

  add_action('wp_ajax_filter_projects', __NAMESPACE__ . '\\filter_projects' );
  add_action('wp_ajax_nopriv_filter_projects', __NAMESPACE__ . '\\filter_projects' ); 

But still not working

[Tartamata]

Fixed thanks you @alwaysblank
I had to add a backslash to WP_Query()